Merging upstream version 1.44.3.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1860 insertions, 0 deletions

diff --git a/fluent-bit/plugins/in_tail/tail_file.c b/fluent-bit/plugins/in_tail/tail_file.c
new file mode 100644
index 000000000..2385f0626
--- /dev/null
+++ b/fluent-bit/plugins/in_tail/tail_file.c
@@ -0,0 +1,1860 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+
+/*  Fluent Bit
+ *  ==========
+ *  Copyright (C) 2015-2022 The Fluent Bit Authors
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <time.h>
+#ifdef FLB_SYSTEM_FREEBSD
+#include <sys/user.h>
+#include <libutil.h>
+#endif
+
+#include <fluent-bit/flb_compat.h>
+#include <fluent-bit/flb_info.h>
+#include <fluent-bit/flb_input_plugin.h>
+#include <fluent-bit/flb_parser.h>
+#ifdef FLB_HAVE_REGEX
+#include <fluent-bit/flb_regex.h>
+#include <fluent-bit/flb_hash_table.h>
+#endif
+
+#include "tail.h"
+#include "tail_file.h"
+#include "tail_config.h"
+#include "tail_db.h"
+#include "tail_signal.h"
+#include "tail_dockermode.h"
+#include "tail_multiline.h"
+#include "tail_scan.h"
+
+#ifdef FLB_SYSTEM_WINDOWS
+#include "win32.h"
+#endif
+
+#include <cfl/cfl.h>
+
+static inline void consume_bytes(char *buf, int bytes, int length)
+{
+    memmove(buf, buf + bytes, length - bytes);
+}
+
+static uint64_t stat_get_st_dev(struct stat *st)
+{
+#ifdef FLB_SYSTEM_WINDOWS
+    /* do you want to contribute with a way to extract volume serial number ? */
+    return 0;
+#else
+    return st->st_dev;
+#endif
+}
+
+static int stat_to_hash_bits(struct flb_tail_config *ctx, struct stat *st,
+                             uint64_t *out_hash)
+{
+    int len;
+    uint64_t st_dev;
+    char tmp[64];
+
+    st_dev = stat_get_st_dev(st);
+
+    len = snprintf(tmp, sizeof(tmp) - 1, "%" PRIu64 ":%" PRIu64,
+                   st_dev, (uint64_t)st->st_ino);
+
+    *out_hash = cfl_hash_64bits(tmp, len);
+    return 0;
+}
+
+static int stat_to_hash_key(struct flb_tail_config *ctx, struct stat *st,
+                            flb_sds_t *key)
+{
+    uint64_t st_dev;
+    flb_sds_t tmp;
+    flb_sds_t buf;
+
+    buf = flb_sds_create_size(64);
+    if (!buf) {
+        return -1;
+    }
+
+    st_dev = stat_get_st_dev(st);
+    tmp = flb_sds_printf(&buf, "%" PRIu64 ":%" PRIu64,
+                         st_dev, (uint64_t)st->st_ino);
+    if (!tmp) {
+        flb_sds_destroy(buf);
+        return -1;
+    }
+
+    *key = buf;
+    return 0;
+}
+
+/* Append custom keys and report the number of records processed */
+static int record_append_custom_keys(struct flb_tail_file *file,
+                                     char *in_data, size_t in_size,
+                                     char **out_data, size_t *out_size)
+{
+    int i;
+    int ret;
+    int records = 0;
+    msgpack_object k;
+    msgpack_object v;
+    struct flb_log_event event;
+    struct flb_tail_config *ctx;
+    struct flb_log_event_encoder encoder;
+    struct flb_log_event_decoder decoder;
+
+    ctx = (struct flb_tail_config *) file->config;
+
+    ret = flb_log_event_decoder_init(&decoder, in_data, in_size);
+
+    if (ret != FLB_EVENT_DECODER_SUCCESS) {
+        return -1;
+    }
+
+    ret = flb_log_event_encoder_init(&encoder, FLB_LOG_EVENT_FORMAT_DEFAULT);
+
+    if (ret != FLB_EVENT_ENCODER_SUCCESS) {
+        flb_log_event_decoder_destroy(&decoder);
+
+        return -2;
+    }
+
+    while (flb_log_event_decoder_next(&decoder, &event) ==
+            FLB_EVENT_DECODER_SUCCESS) {
+
+        ret = flb_log_event_encoder_begin_record(&encoder);
+
+        if (ret == FLB_EVENT_ENCODER_SUCCESS) {
+            ret = flb_log_event_encoder_set_timestamp(&encoder, &event.timestamp);
+        }
+
+        /* append previous map keys */
+        for (i = 0; i < event.body->via.map.size; i++) {
+            k = event.body->via.map.ptr[i].key;
+            v = event.body->via.map.ptr[i].val;
+
+            if (ret == FLB_EVENT_ENCODER_SUCCESS) {
+                ret = flb_log_event_encoder_append_body_msgpack_object(
+                        &encoder,
+                        &k);
+            }
+
+            if (ret == FLB_EVENT_ENCODER_SUCCESS) {
+                ret = flb_log_event_encoder_append_body_msgpack_object(
+                        &encoder,
+                        &v);
+            }
+        }
+
+        /* path_key */
+        if (ctx->path_key != NULL) {
+            if (ret == FLB_EVENT_ENCODER_SUCCESS) {
+                ret = flb_log_event_encoder_append_body_cstring(
+                        &encoder,
+                        file->config->path_key);
+            }
+
+            if (ret == FLB_EVENT_ENCODER_SUCCESS) {
+                ret = flb_log_event_encoder_append_body_cstring(
+                        &encoder,
+                        file->orig_name);
+            }
+        }
+
+        /* offset_key */
+        if (ctx->offset_key != NULL) {
+            if (ret == FLB_EVENT_ENCODER_SUCCESS) {
+                ret = flb_log_event_encoder_append_body_cstring(
+                        &encoder,
+                        file->config->offset_key);
+            }
+
+            if (ret == FLB_EVENT_ENCODER_SUCCESS) {
+                ret = flb_log_event_encoder_append_body_uint64(
+                        &encoder,
+                        file->offset +
+                        file->last_processed_bytes);
+            }
+        }
+
+        if (ret == FLB_EVENT_ENCODER_SUCCESS) {
+            ret = flb_log_event_encoder_commit_record(&encoder);
+        }
+        else {
+            flb_plg_error(file->config->ins, "error packing event : %d", ret);
+
+            flb_log_event_encoder_rollback_record(&encoder);
+        }
+
+        /* counter */
+        records++;
+    }
+
+    *out_data = encoder.output_buffer;
+    *out_size = encoder.output_length;
+
+    /* This function transfers ownership of the internal memory allocated by
+     * sbuffer using msgpack_sbuffer_release which means the caller is
+     * responsible for releasing the memory.
+     */
+    flb_log_event_encoder_claim_internal_buffer_ownership(&encoder);
+
+    flb_log_event_decoder_destroy(&decoder);
+    flb_log_event_encoder_destroy(&encoder);
+
+    return records;
+}
+
+static int flb_tail_repack_map(struct flb_log_event_encoder *encoder,
+                               char *data,
+                               size_t data_size)
+{
+    msgpack_unpacked source_map;
+    size_t           offset;
+    int              result;
+    size_t           index;
+    msgpack_object   value;
+    msgpack_object   key;
+
+    result = FLB_EVENT_ENCODER_SUCCESS;
+
+    if (data_size > 0) {
+        msgpack_unpacked_init(&source_map);
+
+        offset = 0;
+        result = msgpack_unpack_next(&source_map,
+                                     data,
+                                     data_size,
+                                     &offset);
+
+        if (result == MSGPACK_UNPACK_SUCCESS) {
+            result = FLB_EVENT_ENCODER_SUCCESS;
+        }
+        else {
+            result = FLB_EVENT_DECODER_ERROR_DESERIALIZATION_FAILURE;
+        }
+
+        for (index = 0;
+             index < source_map.data.via.map.size &&
+             result == FLB_EVENT_ENCODER_SUCCESS;
+             index++) {
+            key   = source_map.data.via.map.ptr[index].key;
+            value = source_map.data.via.map.ptr[index].val;
+
+            result = flb_log_event_encoder_append_body_msgpack_object(
+                        encoder,
+                        &key);
+
+            if (result == FLB_EVENT_ENCODER_SUCCESS) {
+                result = flb_log_event_encoder_append_body_msgpack_object(
+                            encoder,
+                            &value);
+            }
+        }
+
+        msgpack_unpacked_destroy(&source_map);
+    }
+
+    return result;
+}
+
+int flb_tail_pack_line_map(struct flb_time *time, char **data,
+                           size_t *data_size, struct flb_tail_file *file,
+                           size_t processed_bytes)
+{
+    int result;
+
+    result = flb_log_event_encoder_begin_record(file->sl_log_event_encoder);
+
+    if (result == FLB_EVENT_ENCODER_SUCCESS) {
+        result = flb_log_event_encoder_set_timestamp(
+                    file->sl_log_event_encoder, time);
+    }
+
+    if (result == FLB_EVENT_ENCODER_SUCCESS) {
+        result = flb_tail_repack_map(file->sl_log_event_encoder,
+                                     *data,
+                                     *data_size);
+    }
+
+    /* path_key */
+    if (file->config->path_key != NULL) {
+        if (result == FLB_EVENT_ENCODER_SUCCESS) {
+            result = flb_log_event_encoder_append_body_values(
+                        file->sl_log_event_encoder,
+                        FLB_LOG_EVENT_CSTRING_VALUE(file->config->path_key),
+                        FLB_LOG_EVENT_STRING_VALUE(file->orig_name,
+                                                   file->orig_name_len));
+        }
+    }
+
+    /* offset_key */
+    if (file->config->offset_key != NULL) {
+        if (result == FLB_EVENT_ENCODER_SUCCESS) {
+            result = flb_log_event_encoder_append_body_values(
+                        file->sl_log_event_encoder,
+                        FLB_LOG_EVENT_CSTRING_VALUE(file->config->offset_key),
+                        FLB_LOG_EVENT_UINT64_VALUE(file->offset + processed_bytes));
+        }
+    }
+
+    if (result == FLB_EVENT_ENCODER_SUCCESS) {
+        result = flb_log_event_encoder_commit_record(file->sl_log_event_encoder);
+    }
+    else {
+        flb_log_event_encoder_rollback_record(file->sl_log_event_encoder);
+    }
+
+    if (result != FLB_EVENT_ENCODER_SUCCESS) {
+        flb_plg_error(file->config->ins, "error packing event");
+
+        return -1;
+    }
+
+    return 0;
+}
+
+int flb_tail_file_pack_line(struct flb_time *time, char *data, size_t data_size,
+                            struct flb_tail_file *file, size_t processed_bytes)
+{
+    int result;
+
+    result = flb_log_event_encoder_begin_record(file->sl_log_event_encoder);
+
+    if (result == FLB_EVENT_ENCODER_SUCCESS) {
+        result = flb_log_event_encoder_set_timestamp(
+                    file->sl_log_event_encoder, time);
+    }
+
+    /* path_key */
+    if (file->config->path_key != NULL) {
+        if (result == FLB_EVENT_ENCODER_SUCCESS) {
+            result = flb_log_event_encoder_append_body_values(
+                        file->sl_log_event_encoder,
+                        FLB_LOG_EVENT_CSTRING_VALUE(file->config->path_key),
+                        FLB_LOG_EVENT_STRING_VALUE(file->orig_name,
+                                                   file->orig_name_len));
+        }
+    }
+
+    /* offset_key */
+    if (file->config->offset_key != NULL) {
+        if (result == FLB_EVENT_ENCODER_SUCCESS) {
+            result = flb_log_event_encoder_append_body_values(
+                        file->sl_log_event_encoder,
+                        FLB_LOG_EVENT_CSTRING_VALUE(file->config->offset_key),
+                        FLB_LOG_EVENT_UINT64_VALUE(file->offset + processed_bytes));
+        }
+    }
+
+    if (result == FLB_EVENT_ENCODER_SUCCESS) {
+        result = flb_log_event_encoder_append_body_values(
+                    file->sl_log_event_encoder,
+                    FLB_LOG_EVENT_CSTRING_VALUE(file->config->key),
+                    FLB_LOG_EVENT_STRING_VALUE(data,
+                                               data_size));
+    }
+
+    if (result == FLB_EVENT_ENCODER_SUCCESS) {
+        result = flb_log_event_encoder_commit_record(file->sl_log_event_encoder);
+    }
+
+    if (result != FLB_EVENT_ENCODER_SUCCESS) {
+        flb_plg_error(file->config->ins, "error packing event : %d", result);
+
+        return -1;
+    }
+
+    return 0;
+}
+
+static int ml_stream_buffer_append(struct flb_tail_file *file, char *buf_data, size_t buf_size)
+{
+    int result;
+
+    result = flb_log_event_encoder_emit_raw_record(
+                 file->ml_log_event_encoder,
+                 buf_data, buf_size);
+
+    if (result != FLB_EVENT_ENCODER_SUCCESS) {
+        flb_plg_error(file->config->ins,
+                      "log event raw append error : %d",
+                      result);
+
+        return -1;
+    }
+
+    return 0;
+}
+
+static int ml_stream_buffer_flush(struct flb_tail_config *ctx, struct flb_tail_file *file)
+{
+    if (file->ml_log_event_encoder->output_length > 0) {
+        flb_input_log_append(ctx->ins,
+                             file->tag_buf,
+                             file->tag_len,
+                             file->ml_log_event_encoder->output_buffer,
+                             file->ml_log_event_encoder->output_length);
+
+        flb_log_event_encoder_reset(file->ml_log_event_encoder);
+    }
+
+    return 0;
+}
+
+static int process_content(struct flb_tail_file *file, size_t *bytes)
+{
+    size_t len;
+    int lines = 0;
+    int ret;
+    size_t processed_bytes = 0;
+    char *data;
+    char *end;
+    char *p;
+    void *out_buf;
+    size_t out_size;
+    int crlf;
+    char *line;
+    size_t line_len;
+    char *repl_line;
+    size_t repl_line_len;
+    time_t now = time(NULL);
+    struct flb_time out_time = {0};
+    struct flb_tail_config *ctx;
+
+    ctx = (struct flb_tail_config *) file->config;
+
+    /* Parse the data content */
+    data = file->buf_data;
+    end = data + file->buf_len;
+
+    /* reset last processed bytes */
+    file->last_processed_bytes = 0;
+
+    /* Skip null characters from the head (sometimes introduced by copy-truncate log rotation) */
+    while (data < end && *data == '\0') {
+        data++;
+        processed_bytes++;
+    }
+
+    while (data < end && (p = memchr(data, '\n', end - data))) {
+        len = (p - data);
+        crlf = 0;
+        if (file->skip_next == FLB_TRUE) {
+            data += len + 1;
+            processed_bytes += len + 1;
+            file->skip_next = FLB_FALSE;
+            continue;
+        }
+
+        /*
+         * Empty line (just breakline)
+         * ---------------------------
+         * [NOTE] with the new Multiline core feature and Multiline Filter on
+         * Fluent Bit v1.8.2, there are a couple of cases where stack traces
+         * or multi line patterns expects an empty line (meaning only the
+         * breakline), skipping empty lines on this plugin will break that
+         * functionality.
+         *
+         * We are introducing 'skip_empty_lines=off' configuration
+         * property to revert this behavior if some user is affected by
+         * this change.
+         */
+
+        if (len == 0 && ctx->skip_empty_lines) {
+            data++;
+            processed_bytes++;
+            continue;
+        }
+
+        /* Process '\r\n' */
+        if (len >= 2) {
+            crlf = (data[len-1] == '\r');
+            if (len == 1 && crlf) {
+                data += 2;
+                processed_bytes += 2;
+                continue;
+            }
+        }
+
+        /* Reset time for each line */
+        flb_time_zero(&out_time);
+
+        line = data;
+        line_len = len - crlf;
+        repl_line = NULL;
+
+        if (ctx->ml_ctx) {
+            ret = flb_ml_append_text(ctx->ml_ctx,
+                                     file->ml_stream_id,
+                                     &out_time,
+                                     line,
+                                     line_len);
+            goto go_next;
+        }
+        else if (ctx->docker_mode) {
+            ret = flb_tail_dmode_process_content(now, line, line_len,
+                                                 &repl_line, &repl_line_len,
+                                                 file, ctx);
+            if (ret >= 0) {
+                if (repl_line == line) {
+                    repl_line = NULL;
+                }
+                else {
+                    line = repl_line;
+                    line_len = repl_line_len;
+                }
+                /* Skip normal parsers flow */
+                goto go_next;
+            }
+            else {
+                flb_tail_dmode_flush(file, ctx);
+            }
+        }
+
+#ifdef FLB_HAVE_PARSER
+        if (ctx->parser) {
+            /* Common parser (non-multiline) */
+            ret = flb_parser_do(ctx->parser, line, line_len,
+                                &out_buf, &out_size, &out_time);
+            if (ret >= 0) {
+                if (flb_time_to_nanosec(&out_time) == 0L) {
+                    flb_time_get(&out_time);
+                }
+
+                /* If multiline is enabled, flush any buffered data */
+                if (ctx->multiline == FLB_TRUE) {
+                    flb_tail_mult_flush(file, ctx);
+                }
+
+                flb_tail_pack_line_map(&out_time,
+                                       (char**) &out_buf, &out_size, file,
+                                       processed_bytes);
+
+                flb_free(out_buf);
+            }
+            else {
+                /* Parser failed, pack raw text */
+                flb_tail_file_pack_line(NULL, data, len, file, processed_bytes);
+            }
+        }
+        else if (ctx->multiline == FLB_TRUE) {
+            ret = flb_tail_mult_process_content(now,
+                                                line, line_len,
+                                                file, ctx, processed_bytes);
+
+            /* No multiline */
+            if (ret == FLB_TAIL_MULT_NA) {
+                flb_tail_mult_flush(file, ctx);
+
+                flb_tail_file_pack_line(NULL,
+                                        line, line_len, file, processed_bytes);
+            }
+            else if (ret == FLB_TAIL_MULT_MORE) {
+                /* we need more data, do nothing */
+                goto go_next;
+            }
+            else if (ret == FLB_TAIL_MULT_DONE) {
+                /* Finalized */
+            }
+        }
+        else {
+            flb_tail_file_pack_line(NULL,
+                                    line, line_len, file, processed_bytes);
+        }
+#else
+        flb_tail_file_pack_line(NULL,
+                                line, line_len, file, processed_bytes);
+#endif
+
+    go_next:
+        flb_free(repl_line);
+        repl_line = NULL;
+        /* Adjust counters */
+        data += len + 1;
+        processed_bytes += len + 1;
+        lines++;
+        file->parsed = 0;
+        file->last_processed_bytes += processed_bytes;
+    }
+    file->parsed = file->buf_len;
+
+    if (lines > 0) {
+        /* Append buffer content to a chunk */
+        *bytes = processed_bytes;
+
+        if (file->sl_log_event_encoder->output_length > 0) {
+            flb_input_log_append_records(ctx->ins,
+                                         lines,
+                                         file->tag_buf,
+                                         file->tag_len,
+                                         file->sl_log_event_encoder->output_buffer,
+                                         file->sl_log_event_encoder->output_length);
+
+            flb_log_event_encoder_reset(file->sl_log_event_encoder);
+        }
+    }
+    else if (file->skip_next) {
+        *bytes = file->buf_len;
+    }
+    else {
+        *bytes = processed_bytes;
+    }
+
+    if (ctx->ml_ctx) {
+        ml_stream_buffer_flush(ctx, file);
+    }
+
+    return lines;
+}
+
+static inline void drop_bytes(char *buf, size_t len, int pos, int bytes)
+{
+    memmove(buf + pos,
+            buf + pos + bytes,
+            len - pos - bytes);
+}
+
+#ifdef FLB_HAVE_REGEX
+static void cb_results(const char *name, const char *value,
+                       size_t vlen, void *data)
+{
+    struct flb_hash_table *ht = data;
+
+    if (vlen == 0) {
+        return;
+    }
+
+    flb_hash_table_add(ht, name, strlen(name), (void *) value, vlen);
+}
+#endif
+
+#ifdef FLB_HAVE_REGEX
+static int tag_compose(char *tag, struct flb_regex *tag_regex, char *fname,
+                       char *out_buf, size_t *out_size,
+                       struct flb_tail_config *ctx)
+#else
+static int tag_compose(char *tag, char *fname, char *out_buf, size_t *out_size,
+                       struct flb_tail_config *ctx)
+#endif
+{
+    int i;
+    size_t len;
+    char *p;
+    size_t buf_s = 0;
+#ifdef FLB_HAVE_REGEX
+    ssize_t n;
+    struct flb_regex_search result;
+    struct flb_hash_table *ht;
+    char *beg;
+    char *end;
+    int ret;
+    const char *tmp;
+    size_t tmp_s;
+#endif
+
+#ifdef FLB_HAVE_REGEX
+    if (tag_regex) {
+        n = flb_regex_do(tag_regex, fname, strlen(fname), &result);
+        if (n <= 0) {
+            flb_plg_error(ctx->ins, "invalid tag_regex pattern for file %s",
+                          fname);
+            return -1;
+        }
+        else {
+            ht = flb_hash_table_create(FLB_HASH_TABLE_EVICT_NONE,
+                                       FLB_HASH_TABLE_SIZE, FLB_HASH_TABLE_SIZE);
+            flb_regex_parse(tag_regex, &result, cb_results, ht);
+
+            for (p = tag, beg = p; (beg = strchr(p, '<')); p = end + 2) {
+                if (beg != p) {
+                    len = (beg - p);
+                    memcpy(out_buf + buf_s, p, len);
+                    buf_s += len;
+                }
+
+                beg++;
+
+                end = strchr(beg, '>');
+                if (end && !memchr(beg, '<', end - beg)) {
+                    end--;
+
+                    len = end - beg + 1;
+                    ret = flb_hash_table_get(ht, beg, len, (void *) &tmp, &tmp_s);
+                    if (ret != -1) {
+                        memcpy(out_buf + buf_s, tmp, tmp_s);
+                        buf_s += tmp_s;
+                    }
+                    else {
+                        memcpy(out_buf + buf_s, "_", 1);
+                        buf_s++;
+                    }
+                }
+                else {
+                    flb_plg_error(ctx->ins,
+                                  "missing closing angle bracket in tag %s "
+                                  "at position %lu", tag, beg - tag);
+                    flb_hash_table_destroy(ht);
+                    return -1;
+                }
+            }
+
+            flb_hash_table_destroy(ht);
+            if (*p) {
+                len = strlen(p);
+                memcpy(out_buf + buf_s, p, len);
+                buf_s += len;
+            }
+        }
+    }
+    else {
+#endif
+        p = strchr(tag, '*');
+        if (!p) {
+            return -1;
+        }
+
+        /* Copy tag prefix if any */
+        len = (p - tag);
+        if (len > 0) {
+            memcpy(out_buf, tag, len);
+            buf_s += len;
+        }
+
+        /* Append file name */
+        len = strlen(fname);
+        memcpy(out_buf + buf_s, fname, len);
+        buf_s += len;
+
+        /* Tag suffix (if any) */
+        p++;
+        if (*p) {
+            len = strlen(tag);
+            memcpy(out_buf + buf_s, p, (len - (p - tag)));
+            buf_s += (len - (p - tag));
+        }
+
+        /* Sanitize buffer */
+        for (i = 0; i < buf_s; i++) {
+            if (out_buf[i] == '/' || out_buf[i] == '\\' || out_buf[i] == ':') {
+                if (i > 0) {
+                    out_buf[i] = '.';
+                }
+                else {
+                    drop_bytes(out_buf, buf_s, i, 1);
+                    buf_s--;
+                    i--;
+                }
+            }
+
+            if (i > 0 && out_buf[i] == '.') {
+                if (out_buf[i - 1] == '.') {
+                    drop_bytes(out_buf, buf_s, i, 1);
+                    buf_s--;
+                    i--;
+                }
+            }
+            else if (out_buf[i] == '*') {
+                    drop_bytes(out_buf, buf_s, i, 1);
+                    buf_s--;
+                    i--;
+            }
+        }
+
+        /* Check for an ending '.' */
+        if (out_buf[buf_s - 1] == '.') {
+            drop_bytes(out_buf, buf_s, buf_s - 1, 1);
+            buf_s--;
+        }
+#ifdef FLB_HAVE_REGEX
+    }
+#endif
+
+    out_buf[buf_s] = '\0';
+    *out_size = buf_s;
+
+    return 0;
+}
+
+static inline int flb_tail_file_exists(struct stat *st,
+                                       struct flb_tail_config *ctx)
+{
+    int ret;
+    uint64_t hash;
+
+    ret = stat_to_hash_bits(ctx, st, &hash);
+    if (ret != 0) {
+        return -1;
+    }
+
+    /* static hash */
+    if (flb_hash_table_exists(ctx->static_hash, hash)) {
+        return FLB_TRUE;
+    }
+
+    /* event hash */
+    if (flb_hash_table_exists(ctx->event_hash, hash)) {
+        return FLB_TRUE;
+    }
+
+    return FLB_FALSE;
+}
+
+/*
+ * Based in the configuration or database offset, set the proper 'offset' for the
+ * file in question.
+ */
+static int set_file_position(struct flb_tail_config *ctx,
+                             struct flb_tail_file *file)
+{
+    int64_t ret;
+
+#ifdef FLB_HAVE_SQLDB
+    /*
+     * If the database option is enabled, try to gather the file position. The
+     * database function updates the file->offset entry.
+     */
+    if (ctx->db) {
+        ret = flb_tail_db_file_set(file, ctx);
+        if (ret == 0) {
+            if (file->offset > 0) {
+                ret = lseek(file->fd, file->offset, SEEK_SET);
+                if (ret == -1) {
+                    flb_errno();
+                    return -1;
+                }
+            }
+            else if (ctx->read_from_head == FLB_FALSE) {
+                ret = lseek(file->fd, 0, SEEK_END);
+                if (ret == -1) {
+                    flb_errno();
+                    return -1;
+                }
+                file->offset = ret;
+                flb_tail_db_file_offset(file, ctx);
+            }
+            return 0;
+        }
+    }
+#endif
+
+    if (ctx->read_from_head == FLB_TRUE) {
+        /* no need to seek, offset position is already zero */
+        return 0;
+    }
+
+    /* tail... */
+    ret = lseek(file->fd, 0, SEEK_END);
+    if (ret == -1) {
+        flb_errno();
+        return -1;
+    }
+    file->offset = ret;
+
+    return 0;
+}
+
+/* Multiline flush callback: invoked every time some content is complete */
+static int ml_flush_callback(struct flb_ml_parser *parser,
+                             struct flb_ml_stream *mst,
+                             void *data, char *buf_data, size_t buf_size)
+{
+    int result;
+    size_t mult_size = 0;
+    char *mult_buf = NULL;
+    struct flb_tail_file *file = data;
+    struct flb_tail_config *ctx = file->config;
+
+    if (ctx->path_key == NULL && ctx->offset_key == NULL) {
+        ml_stream_buffer_append(file, buf_data, buf_size);
+    }
+    else {
+        /* adjust the records in a new buffer */
+        result = record_append_custom_keys(file,
+                                           buf_data,
+                                           buf_size,
+                                           &mult_buf,
+                                           &mult_size);
+
+        if (result < 0) {
+            ml_stream_buffer_append(file, buf_data, buf_size);
+        }
+        else {
+            ml_stream_buffer_append(file, mult_buf, mult_size);
+
+            flb_free(mult_buf);
+        }
+    }
+
+    if (mst->forced_flush) {
+        ml_stream_buffer_flush(ctx, file);
+    }
+
+    return 0;
+}
+
+int flb_tail_file_append(char *path, struct stat *st, int mode,
+                         struct flb_tail_config *ctx)
+{
+    int fd;
+    int ret;
+    uint64_t stream_id;
+    uint64_t ts;
+    uint64_t hash_bits;
+    flb_sds_t hash_key;
+    size_t len;
+    char *tag;
+    char *name;
+    size_t tag_len;
+    struct flb_tail_file *file;
+    struct stat lst;
+    flb_sds_t inode_str;
+
+    if (!S_ISREG(st->st_mode)) {
+        return -1;
+    }
+
+    if (flb_tail_file_exists(st, ctx) == FLB_TRUE) {
+        return -1;
+    }
+
+    fd = open(path, O_RDONLY);
+    if (fd == -1) {
+        flb_errno();
+        flb_plg_error(ctx->ins, "cannot open %s", path);
+        return -1;
+    }
+
+    file = flb_calloc(1, sizeof(struct flb_tail_file));
+    if (!file) {
+        flb_errno();
+        goto error;
+    }
+
+    /* Initialize */
+    file->watch_fd  = -1;
+    file->fd        = fd;
+
+    /* On non-windows environments check if the original path is a link */
+    ret = lstat(path, &lst);
+    if (ret == 0) {
+        if (S_ISLNK(lst.st_mode)) {
+            file->is_link = FLB_TRUE;
+            file->link_inode = lst.st_ino;
+        }
+    }
+
+    /* get unique hash for this file */
+    ret = stat_to_hash_bits(ctx, st, &hash_bits);
+    if (ret != 0) {
+        flb_plg_error(ctx->ins, "error procesisng hash bits for file %s", path);
+        goto error;
+    }
+    file->hash_bits = hash_bits;
+
+    /* store the hash key used for hash_bits */
+    ret = stat_to_hash_key(ctx, st, &hash_key);
+    if (ret != 0) {
+        flb_plg_error(ctx->ins, "error procesisng hash key for file %s", path);
+        goto error;
+    }
+    file->hash_key = hash_key;
+
+    file->inode     = st->st_ino;
+    file->offset    = 0;
+    file->size      = st->st_size;
+    file->buf_len   = 0;
+    file->parsed    = 0;
+    file->config    = ctx;
+    file->tail_mode = mode;
+    file->tag_len   = 0;
+    file->tag_buf   = NULL;
+    file->rotated   = 0;
+    file->pending_bytes = 0;
+    file->mult_firstline = FLB_FALSE;
+    file->mult_keys = 0;
+    file->mult_flush_timeout = 0;
+    file->mult_skipping = FLB_FALSE;
+
+    /*
+     * Duplicate string into 'file' structure, the called function
+     * take cares to resolve real-name of the file in case we are
+     * running in a non-Linux system.
+     *
+     * Depending of the operating system, the way to obtain the file
+     * name associated to it file descriptor can have different behaviors
+     * specifically if it root path it's under a symbolic link. On Linux
+     * we can trust the file name but in others it's better to solve it
+     * with some extra calls.
+     */
+    ret = flb_tail_file_name_dup(path, file);
+    if (!file->name) {
+        flb_errno();
+        goto error;
+    }
+
+    /* We keep a copy of the initial filename in orig_name. This is required
+     * for path_key to continue working after rotation. */
+    file->orig_name = flb_strdup(file->name);
+    if (!file->orig_name) {
+        flb_free(file->name);
+        flb_errno();
+        goto error;
+    }
+    file->orig_name_len = file->name_len;
+
+    /* multiline msgpack buffers */
+    file->mult_records = 0;
+    msgpack_sbuffer_init(&file->mult_sbuf);
+    msgpack_packer_init(&file->mult_pck, &file->mult_sbuf,
+                        msgpack_sbuffer_write);
+
+    /* docker mode */
+    file->dmode_flush_timeout = 0;
+    file->dmode_complete = true;
+    file->dmode_buf = flb_sds_create_size(ctx->docker_mode == FLB_TRUE ? 65536 : 0);
+    file->dmode_lastline = flb_sds_create_size(ctx->docker_mode == FLB_TRUE ? 20000 : 0);
+    file->dmode_firstline = false;
+#ifdef FLB_HAVE_SQLDB
+    file->db_id     = 0;
+#endif
+    file->skip_next = FLB_FALSE;
+    file->skip_warn = FLB_FALSE;
+
+    /* Multiline core mode */
+    if (ctx->ml_ctx) {
+        /*
+         * Create inode str to get stream_id.
+         *
+         * If stream_id is created by filename,
+         * it will be same after file rotation and it causes invalid destruction:
+         *
+         *  - https://github.com/fluent/fluent-bit/issues/4190
+         */
+        inode_str = flb_sds_create_size(64);
+        flb_sds_printf(&inode_str, "%"PRIu64, file->inode);
+
+        /* Create a stream for this file */
+        ret = flb_ml_stream_create(ctx->ml_ctx,
+                                   inode_str, flb_sds_len(inode_str),
+                                   ml_flush_callback, file,
+                                   &stream_id);
+        if (ret != 0) {
+            flb_plg_error(ctx->ins,
+                          "could not create multiline stream for file: %s",
+                          inode_str);
+            flb_sds_destroy(inode_str);
+            goto error;
+        }
+        file->ml_stream_id = stream_id;
+        flb_sds_destroy(inode_str);
+
+        /*
+         * Multiline core file buffer: the multiline core functionality invokes a callback everytime a message is ready
+         * to be processed by the caller, this can be a multiline message or a message that is considered 'complete'. In
+         * the previous version of Tail, when it received a message this message was automatically ingested into the pipeline
+         * without any previous buffering which leads to performance degradation.
+         *
+         * The msgpack buffer 'ml_sbuf' keeps all ML provided records and it's flushed just when the file processor finish
+         * processing the "read() bytes".
+         */
+    }
+
+    /* Local buffer */
+    file->buf_size = ctx->buf_chunk_size;
+    file->buf_data = flb_malloc(file->buf_size);
+    if (!file->buf_data) {
+        flb_errno();
+        goto error;
+    }
+
+    /* Initialize (optional) dynamic tag */
+    if (ctx->dynamic_tag == FLB_TRUE) {
+        len = ctx->ins->tag_len + strlen(path) + 1;
+        tag = flb_malloc(len);
+        if (!tag) {
+            flb_errno();
+            flb_plg_error(ctx->ins, "failed to allocate tag buffer");
+            goto error;
+        }
+#ifdef FLB_HAVE_REGEX
+        ret = tag_compose(ctx->ins->tag, ctx->tag_regex, path, tag, &tag_len, ctx);
+#else
+        ret = tag_compose(ctx->ins->tag, path, tag, &tag_len, ctx);
+#endif
+        if (ret == 0) {
+            file->tag_len = tag_len;
+            file->tag_buf = flb_strdup(tag);
+        }
+        flb_free(tag);
+        if (ret != 0) {
+            flb_plg_error(ctx->ins, "failed to compose tag for file: %s", path);
+            goto error;
+        }
+    }
+    else {
+        file->tag_len = strlen(ctx->ins->tag);
+        file->tag_buf = flb_strdup(ctx->ins->tag);
+    }
+    if (!file->tag_buf) {
+        flb_plg_error(ctx->ins, "failed to set tag for file: %s", path);
+        flb_errno();
+        goto error;
+    }
+
+    if (mode == FLB_TAIL_STATIC) {
+        mk_list_add(&file->_head, &ctx->files_static);
+        ctx->files_static_count++;
+        flb_hash_table_add(ctx->static_hash, file->hash_key, flb_sds_len(file->hash_key),
+                           file, sizeof(file));
+        tail_signal_manager(file->config);
+    }
+    else if (mode == FLB_TAIL_EVENT) {
+        mk_list_add(&file->_head, &ctx->files_event);
+        flb_hash_table_add(ctx->event_hash, file->hash_key, flb_sds_len(file->hash_key),
+                           file, sizeof(file));
+
+        /* Register this file into the fs_event monitoring */
+        ret = flb_tail_fs_add(ctx, file);
+        if (ret == -1) {
+            flb_plg_error(ctx->ins, "could not register file into fs_events");
+            goto error;
+        }
+    }
+
+    /* Set the file position (database offset, head or tail) */
+    ret = set_file_position(ctx, file);
+    if (ret == -1) {
+        flb_tail_file_remove(file);
+        goto error;
+    }
+
+    /* Remaining bytes to read */
+    file->pending_bytes = file->size - file->offset;
+
+#ifdef FLB_HAVE_METRICS
+    name = (char *) flb_input_name(ctx->ins);
+    ts = cfl_time_now();
+    cmt_counter_inc(ctx->cmt_files_opened, ts, 1, (char *[]) {name});
+
+    /* Old api */
+    flb_metrics_sum(FLB_TAIL_METRIC_F_OPENED, 1, ctx->ins->metrics);
+#endif
+
+    file->sl_log_event_encoder = flb_log_event_encoder_create(
+                                    FLB_LOG_EVENT_FORMAT_DEFAULT);
+
+    if (file->sl_log_event_encoder == NULL) {
+        flb_tail_file_remove(file);
+
+        goto error;
+    }
+
+    file->ml_log_event_encoder = flb_log_event_encoder_create(
+                                    FLB_LOG_EVENT_FORMAT_DEFAULT);
+
+    if (file->ml_log_event_encoder == NULL) {
+        flb_tail_file_remove(file);
+
+        goto error;
+    }
+
+    flb_plg_debug(ctx->ins,
+                  "inode=%"PRIu64" with offset=%"PRId64" appended as %s",
+                  file->inode, file->offset, path);
+    return 0;
+
+error:
+    if (file) {
+        if (file->buf_data) {
+            flb_free(file->buf_data);
+        }
+        if (file->name) {
+            flb_free(file->name);
+        }
+        flb_free(file);
+    }
+    close(fd);
+
+    return -1;
+}
+
+void flb_tail_file_remove(struct flb_tail_file *file)
+{
+    uint64_t ts;
+    char *name;
+    struct flb_tail_config *ctx;
+
+    ctx = file->config;
+
+    flb_plg_debug(ctx->ins, "inode=%"PRIu64" removing file name %s",
+                  file->inode, file->name);
+
+    /* remove the multiline.core stream */
+    if (ctx->ml_ctx && file->ml_stream_id > 0) {
+        /* destroy ml stream */
+        flb_ml_stream_id_destroy_all(ctx->ml_ctx, file->ml_stream_id);
+    }
+
+    if (file->rotated > 0) {
+#ifdef FLB_HAVE_SQLDB
+        /*
+         * Make sure to remove a the file entry from the database if the file
+         * was rotated and it's not longer being monitored.
+         */
+        if (ctx->db) {
+            flb_tail_db_file_delete(file, file->config);
+        }
+#endif
+        mk_list_del(&file->_rotate_head);
+    }
+
+    msgpack_sbuffer_destroy(&file->mult_sbuf);
+
+    if (file->sl_log_event_encoder != NULL) {
+        flb_log_event_encoder_destroy(file->sl_log_event_encoder);
+    }
+
+    if (file->ml_log_event_encoder != NULL) {
+        flb_log_event_encoder_destroy(file->ml_log_event_encoder);
+    }
+
+    flb_sds_destroy(file->dmode_buf);
+    flb_sds_destroy(file->dmode_lastline);
+    mk_list_del(&file->_head);
+    flb_tail_fs_remove(ctx, file);
+
+    /* avoid deleting file with -1 fd */
+    if (file->fd != -1) {
+        close(file->fd);
+    }
+    if (file->tag_buf) {
+        flb_free(file->tag_buf);
+    }
+
+    /* remove any potential entry from the hash tables */
+    flb_hash_table_del(ctx->static_hash, file->hash_key);
+    flb_hash_table_del(ctx->event_hash, file->hash_key);
+
+    flb_free(file->buf_data);
+    flb_free(file->name);
+    flb_free(file->orig_name);
+    flb_free(file->real_name);
+    flb_sds_destroy(file->hash_key);
+
+#ifdef FLB_HAVE_METRICS
+    name = (char *) flb_input_name(ctx->ins);
+    ts = cfl_time_now();
+    cmt_counter_inc(ctx->cmt_files_closed, ts, 1, (char *[]) {name});
+
+    /* old api */
+    flb_metrics_sum(FLB_TAIL_METRIC_F_CLOSED, 1, ctx->ins->metrics);
+#endif
+
+    flb_free(file);
+}
+
+int flb_tail_file_remove_all(struct flb_tail_config *ctx)
+{
+    int count = 0;
+    struct mk_list *head;
+    struct mk_list *tmp;
+    struct flb_tail_file *file;
+
+    mk_list_foreach_safe(head, tmp, &ctx->files_static) {
+        file = mk_list_entry(head, struct flb_tail_file, _head);
+        flb_tail_file_remove(file);
+        count++;
+    }
+
+    mk_list_foreach_safe(head, tmp, &ctx->files_event) {
+        file = mk_list_entry(head, struct flb_tail_file, _head);
+        flb_tail_file_remove(file);
+        count++;
+    }
+
+    return count;
+}
+
+static int adjust_counters(struct flb_tail_config *ctx, struct flb_tail_file *file)
+{
+    int ret;
+    int64_t offset;
+    struct stat st;
+
+    ret = fstat(file->fd, &st);
+    if (ret == -1) {
+        flb_errno();
+        return FLB_TAIL_ERROR;
+    }
+
+    /* Check if the file was truncated */
+    if (file->offset > st.st_size) {
+        offset = lseek(file->fd, 0, SEEK_SET);
+        if (offset == -1) {
+            flb_errno();
+            return FLB_TAIL_ERROR;
+        }
+
+        flb_plg_debug(ctx->ins, "inode=%"PRIu64" file truncated %s",
+                      file->inode, file->name);
+        file->offset = offset;
+        file->buf_len = 0;
+
+        /* Update offset in the database file */
+#ifdef FLB_HAVE_SQLDB
+        if (ctx->db) {
+            flb_tail_db_file_offset(file, ctx);
+        }
+#endif
+    }
+    else {
+        file->size = st.st_size;
+        file->pending_bytes = (st.st_size - file->offset);
+    }
+
+    return FLB_TAIL_OK;
+}
+
+int flb_tail_file_chunk(struct flb_tail_file *file)
+{
+    int ret;
+    char *tmp;
+    size_t size;
+    size_t capacity;
+    size_t processed_bytes;
+    ssize_t bytes;
+    struct flb_tail_config *ctx;
+
+    /* Check if we the engine issued a pause */
+    ctx = file->config;
+    if (flb_input_buf_paused(ctx->ins) == FLB_TRUE) {
+        return FLB_TAIL_BUSY;
+    }
+
+    capacity = (file->buf_size - file->buf_len) - 1;
+    if (capacity < 1) {
+        /*
+         * If there is no more room for more data, try to increase the
+         * buffer under the limit of buffer_max_size.
+         */
+        if (file->buf_size >= ctx->buf_max_size) {
+            if (ctx->skip_long_lines == FLB_FALSE) {
+                flb_plg_error(ctx->ins, "file=%s requires a larger buffer size, "
+                          "lines are too long. Skipping file.", file->name);
+                return FLB_TAIL_ERROR;
+            }
+
+            /* Warn the user */
+            if (file->skip_warn == FLB_FALSE) {
+                flb_plg_warn(ctx->ins, "file=%s have long lines. "
+                             "Skipping long lines.", file->name);
+                file->skip_warn = FLB_TRUE;
+            }
+
+            /* Do buffer adjustments */
+            file->offset += file->buf_len;
+            file->buf_len = 0;
+            file->skip_next = FLB_TRUE;
+        }
+        else {
+            size = file->buf_size + ctx->buf_chunk_size;
+            if (size > ctx->buf_max_size) {
+                size = ctx->buf_max_size;
+            }
+
+            /* Increase the buffer size */
+            tmp = flb_realloc(file->buf_data, size);
+            if (tmp) {
+                flb_plg_trace(ctx->ins, "file=%s increase buffer size "
+                              "%lu => %lu bytes",
+                              file->name, file->buf_size, size);
+                file->buf_data = tmp;
+                file->buf_size = size;
+            }
+            else {
+                flb_errno();
+                flb_plg_error(ctx->ins, "cannot increase buffer size for %s, "
+                          "skipping file.", file->name);
+                return FLB_TAIL_ERROR;
+            }
+        }
+        capacity = (file->buf_size - file->buf_len) - 1;
+    }
+
+    bytes = read(file->fd, file->buf_data + file->buf_len, capacity);
+    if (bytes > 0) {
+        /* we read some data, let the content processor take care of it */
+        file->buf_len += bytes;
+        file->buf_data[file->buf_len] = '\0';
+
+        /* Now that we have some data in the buffer, call the data processor
+         * which aims to cut lines and register the entries into the engine.
+         *
+         * The returned value is the absolute offset the file must be seek
+         * now. It may need to get back a few bytes at the beginning of a new
+         * line.
+         */
+        ret = process_content(file, &processed_bytes);
+        if (ret < 0) {
+            flb_plg_debug(ctx->ins, "inode=%"PRIu64" file=%s process content ERROR",
+                          file->inode, file->name);
+            return FLB_TAIL_ERROR;
+        }
+
+        /* Adjust the file offset and buffer */
+        file->offset += processed_bytes;
+        consume_bytes(file->buf_data, processed_bytes, file->buf_len);
+        file->buf_len -= processed_bytes;
+        file->buf_data[file->buf_len] = '\0';
+
+#ifdef FLB_HAVE_SQLDB
+        if (file->config->db) {
+            flb_tail_db_file_offset(file, file->config);
+        }
+#endif
+
+        /* adjust file counters, returns FLB_TAIL_OK or FLB_TAIL_ERROR */
+        ret = adjust_counters(ctx, file);
+
+        /* Data was consumed but likely some bytes still remain */
+        return ret;
+    }
+    else if (bytes == 0) {
+        /* We reached the end of file, let's wait for some incoming data */
+        ret = adjust_counters(ctx, file);
+        if (ret == FLB_TAIL_OK) {
+            return FLB_TAIL_WAIT;
+        }
+        else {
+            return FLB_TAIL_ERROR;
+        }
+    }
+    else {
+        /* error */
+        flb_errno();
+        flb_plg_error(ctx->ins, "error reading %s", file->name);
+        return FLB_TAIL_ERROR;
+    }
+
+    return FLB_TAIL_ERROR;
+}
+
+/* Returns FLB_TRUE if a file has been rotated, otherwise FLB_FALSE */
+int flb_tail_file_is_rotated(struct flb_tail_config *ctx,
+                             struct flb_tail_file *file)
+{
+    int ret;
+    char *name;
+    struct stat st;
+
+    /*
+     * Do not double-check already rotated files since the caller of this
+     * function will trigger a rotation.
+     */
+    if (file->rotated != 0) {
+        return FLB_FALSE;
+    }
+
+    /* Check if the 'original monitored file' is a link and rotated */
+    if (file->is_link == FLB_TRUE) {
+        ret = lstat(file->name, &st);
+        if (ret == -1) {
+            /* Broken link or missing file */
+            if (errno == ENOENT) {
+                flb_plg_info(ctx->ins, "inode=%"PRIu64" link_rotated: %s",
+                             file->link_inode, file->name);
+                return FLB_TRUE;
+            }
+            else {
+                flb_errno();
+                flb_plg_error(ctx->ins,
+                              "link_inode=%"PRIu64" cannot detect if file: %s",
+                              file->link_inode, file->name);
+                return -1;
+            }
+        }
+        else {
+            /* The file name is there, check if the same that we have */
+            if (st.st_ino != file->link_inode) {
+                return FLB_TRUE;
+            }
+        }
+    }
+
+    /* Retrieve the real file name, operating system lookup */
+    name = flb_tail_file_name(file);
+    if (!name) {
+        flb_plg_error(ctx->ins,
+                      "inode=%"PRIu64" cannot detect if file was rotated: %s",
+                      file->inode, file->name);
+        return -1;
+    }
+
+
+    /* Get stats from the file name */
+    ret = stat(name, &st);
+    if (ret == -1) {
+        flb_errno();
+        flb_free(name);
+        return -1;
+    }
+
+    /* Compare inodes and names */
+    if (file->inode == st.st_ino &&
+        flb_tail_target_file_name_cmp(name, file) == 0) {
+        flb_free(name);
+        return FLB_FALSE;
+    }
+
+    flb_plg_debug(ctx->ins, "inode=%"PRIu64" rotated: %s => %s",
+                  file->inode, file->name, name);
+
+    flb_free(name);
+    return FLB_TRUE;
+}
+
+/* Promote a event in the static list to the dynamic 'events' interface */
+int flb_tail_file_to_event(struct flb_tail_file *file)
+{
+    int ret;
+    struct stat st;
+    struct flb_tail_config *ctx = file->config;
+
+    /* Check if the file promoted have pending bytes */
+    ret = fstat(file->fd, &st);
+    if (ret != 0) {
+        flb_errno();
+        return -1;
+    }
+
+    if (file->offset < st.st_size) {
+        file->pending_bytes = (st.st_size - file->offset);
+        tail_signal_pending(file->config);
+    }
+    else {
+        file->pending_bytes = 0;
+    }
+
+    /* Check if the file has been rotated */
+    ret = flb_tail_file_is_rotated(ctx, file);
+    if (ret == FLB_TRUE) {
+        flb_tail_file_rotated(file);
+    }
+
+    /* Notify the fs-event handler that we will start monitoring this 'file' */
+    ret = flb_tail_fs_add(ctx, file);
+    if (ret == -1) {
+        return -1;
+    }
+
+    /* List swap: change from 'static' to 'event' list */
+    mk_list_del(&file->_head);
+    ctx->files_static_count--;
+    flb_hash_table_del(ctx->static_hash, file->hash_key);
+
+    mk_list_add(&file->_head, &file->config->files_event);
+    flb_hash_table_add(ctx->event_hash, file->hash_key, flb_sds_len(file->hash_key),
+                       file, sizeof(file));
+
+    file->tail_mode = FLB_TAIL_EVENT;
+
+    return 0;
+}
+
+/*
+ * Given an open file descriptor, return the filename. This function is a
+ * bit slow and it aims to be used only when a file is rotated.
+ */
+char *flb_tail_file_name(struct flb_tail_file *file)
+{
+    int ret;
+    char *buf;
+#ifdef __linux__
+    ssize_t s;
+    char tmp[128];
+#elif defined(__APPLE__)
+    char path[PATH_MAX];
+#elif defined(FLB_SYSTEM_WINDOWS)
+    HANDLE h;
+#elif defined(FLB_SYSTEM_FREEBSD)
+    struct kinfo_file *file_entries;
+    int file_count;
+    int file_index;
+#endif
+
+    buf = flb_malloc(PATH_MAX);
+    if (!buf) {
+        flb_errno();
+        return NULL;
+    }
+
+#ifdef __linux__
+    ret = snprintf(tmp, sizeof(tmp) - 1, "/proc/%i/fd/%i", getpid(), file->fd);
+    if (ret == -1) {
+        flb_errno();
+        flb_free(buf);
+        return NULL;
+    }
+
+    s = readlink(tmp, buf, PATH_MAX);
+    if (s == -1) {
+        flb_free(buf);
+        flb_errno();
+        return NULL;
+    }
+    buf[s] = '\0';
+
+#elif __APPLE__
+    int len;
+
+    ret = fcntl(file->fd, F_GETPATH, path);
+    if (ret == -1) {
+        flb_errno();
+        flb_free(buf);
+        return NULL;
+    }
+
+    len = strlen(path);
+    memcpy(buf, path, len);
+    buf[len] = '\0';
+
+#elif defined(FLB_SYSTEM_WINDOWS)
+    int len;
+
+    h = (HANDLE) _get_osfhandle(file->fd);
+    if (h == INVALID_HANDLE_VALUE) {
+        flb_errno();
+        flb_free(buf);
+        return NULL;
+    }
+
+    /* This function returns the length of the string excluding "\0"
+     * and the resulting path has a "\\?\" prefix.
+     */
+    len = GetFinalPathNameByHandleA(h, buf, PATH_MAX, FILE_NAME_NORMALIZED);
+    if (len == 0 || len >= PATH_MAX) {
+        flb_free(buf);
+        return NULL;
+    }
+
+    if (strstr(buf, "\\\\?\\")) {
+        memmove(buf, buf + 4, len + 1);
+    }
+#elif defined(FLB_SYSTEM_FREEBSD)
+    if ((file_entries = kinfo_getfile(getpid(), &file_count)) == NULL) {
+        flb_free(buf);
+        return NULL;
+    }
+
+    for (file_index=0; file_index < file_count; file_index++) {
+        if (file_entries[file_index].kf_fd == file->fd) {
+            strncpy(buf, file_entries[file_index].kf_path, PATH_MAX - 1);
+            buf[PATH_MAX - 1] = 0;
+            break;
+        }
+    }
+    free(file_entries);
+#endif
+    return buf;
+}
+
+int flb_tail_file_name_dup(char *path, struct flb_tail_file *file)
+{
+    file->name = flb_strdup(path);
+    if (!file->name) {
+        flb_errno();
+        return -1;
+    }
+    file->name_len = strlen(file->name);
+
+    if (file->real_name) {
+        flb_free(file->real_name);
+    }
+
+    file->real_name = flb_tail_file_name(file);
+    if (!file->real_name) {
+        flb_errno();
+        flb_free(file->name);
+        file->name = NULL;
+        return -1;
+    }
+
+    return 0;
+}
+
+/* Invoked every time a file was rotated */
+int flb_tail_file_rotated(struct flb_tail_file *file)
+{
+    int ret;
+    uint64_t ts;
+    char *name;
+    char *i_name;
+    char *tmp;
+    struct stat st;
+    struct flb_tail_config *ctx = file->config;
+
+    /* Get the new file name */
+    name = flb_tail_file_name(file);
+    if (!name) {
+        return -1;
+    }
+
+    flb_plg_debug(ctx->ins, "inode=%"PRIu64" rotated %s -> %s",
+                  file->inode, file->name, name);
+
+    /* Update local file entry */
+    tmp = file->name;
+    flb_tail_file_name_dup(name, file);
+    flb_plg_info(ctx->ins, "inode=%"PRIu64" handle rotation(): %s => %s",
+                 file->inode, tmp, file->name);
+    if (file->rotated == 0) {
+        file->rotated = time(NULL);
+        mk_list_add(&file->_rotate_head, &file->config->files_rotated);
+
+    /* Rotate the file in the database */
+#ifdef FLB_HAVE_SQLDB
+        if (file->config->db) {
+            ret = flb_tail_db_file_rotate(name, file, file->config);
+            if (ret == -1) {
+                flb_plg_error(ctx->ins, "could not rotate file %s->%s in database",
+                              file->name, name);
+            }
+        }
+#endif
+
+#ifdef FLB_HAVE_METRICS
+        i_name = (char *) flb_input_name(ctx->ins);
+        ts = cfl_time_now();
+        cmt_counter_inc(ctx->cmt_files_rotated, ts, 1, (char *[]) {i_name});
+
+        /* OLD api */
+        flb_metrics_sum(FLB_TAIL_METRIC_F_ROTATED,
+                        1, file->config->ins->metrics);
+#endif
+
+        /* Check if a new file has been created */
+        ret = stat(tmp, &st);
+        if (ret == 0 && st.st_ino != file->inode) {
+            if (flb_tail_file_exists(&st, ctx) == FLB_FALSE) {
+                ret = flb_tail_file_append(tmp, &st, FLB_TAIL_STATIC, ctx);
+                if (ret == -1) {
+                    flb_tail_scan(ctx->path_list, ctx);
+                }
+                else {
+                    tail_signal_manager(file->config);
+                }
+            }
+        }
+    }
+    flb_free(tmp);
+    flb_free(name);
+
+    return 0;
+}
+
+static int check_purge_deleted_file(struct flb_tail_config *ctx,
+                                    struct flb_tail_file *file, time_t ts)
+{
+    int ret;
+    struct stat st;
+
+    ret = fstat(file->fd, &st);
+    if (ret == -1) {
+        flb_plg_debug(ctx->ins, "error stat(2) %s, removing", file->name);
+        flb_tail_file_remove(file);
+        return FLB_TRUE;
+    }
+
+    if (st.st_nlink == 0) {
+        flb_plg_debug(ctx->ins, "purge: monitored file has been deleted: %s",
+                      file->name);
+#ifdef FLB_HAVE_SQLDB
+        if (ctx->db) {
+            /* Remove file entry from the database */
+            flb_tail_db_file_delete(file, file->config);
+        }
+#endif
+        /* Remove file from the monitored list */
+        flb_tail_file_remove(file);
+        return FLB_TRUE;
+    }
+
+    return FLB_FALSE;
+}
+
+/* Purge rotated and deleted files */
+int flb_tail_file_purge(struct flb_input_instance *ins,
+                        struct flb_config *config, void *context)
+{
+    int ret;
+    int count = 0;
+    struct mk_list *tmp;
+    struct mk_list *head;
+    struct flb_tail_file *file;
+    struct flb_tail_config *ctx = context;
+    time_t now;
+    struct stat st;
+
+    /* Rotated files */
+    now = time(NULL);
+    mk_list_foreach_safe(head, tmp, &ctx->files_rotated) {
+        file = mk_list_entry(head, struct flb_tail_file, _rotate_head);
+        if ((file->rotated + ctx->rotate_wait) <= now) {
+            ret = fstat(file->fd, &st);
+            if (ret == 0) {
+                flb_plg_debug(ctx->ins,
+                              "inode=%"PRIu64" purge rotated file %s " \
+                              "(offset=%"PRId64" / size = %"PRIu64")",
+                              file->inode, file->name, file->offset, (uint64_t)st.st_size);
+                if (file->pending_bytes > 0 && flb_input_buf_paused(ins)) {
+                    flb_plg_warn(ctx->ins, "purged rotated file while data "
+                                 "ingestion is paused, consider increasing "
+                                 "rotate_wait");
+                }
+            }
+            else {
+                flb_plg_debug(ctx->ins,
+                              "inode=%"PRIu64" purge rotated file %s (offset=%"PRId64")",
+                              file->inode, file->name, file->offset);
+            }
+
+            flb_tail_file_remove(file);
+            count++;
+        }
+    }
+
+    /*
+     * Deleted files: under high load scenarios, exists the chances that in
+     * our event loop we miss some notifications about a file. In order to
+     * sanitize our list of monitored files we will iterate all of them and check
+     * if they have been deleted or not.
+     */
+    mk_list_foreach_safe(head, tmp, &ctx->files_static) {
+        file = mk_list_entry(head, struct flb_tail_file, _head);
+        check_purge_deleted_file(ctx, file, now);
+    }
+    mk_list_foreach_safe(head, tmp, &ctx->files_event) {
+        file = mk_list_entry(head, struct flb_tail_file, _head);
+        check_purge_deleted_file(ctx, file, now);
+    }
+
+    return count;
+}