Merging upstream version 1.44.3.

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

1 files changed, 857 insertions, 0 deletions

diff --git a/collectors/systemd-journal.plugin/systemd-journal-files.c b/collectors/systemd-journal.plugin/systemd-journal-files.c
new file mode 100644
index 000000000..56496df22
--- /dev/null
+++ b/collectors/systemd-journal.plugin/systemd-journal-files.c
@@ -0,0 +1,857 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "systemd-internals.h"
+
+#define SYSTEMD_JOURNAL_MAX_SOURCE_LEN 64
+#define VAR_LOG_JOURNAL_MAX_DEPTH 10
+
+struct journal_directory journal_directories[MAX_JOURNAL_DIRECTORIES] = { 0 };
+DICTIONARY *journal_files_registry = NULL;
+DICTIONARY *used_hashes_registry = NULL;
+
+static usec_t systemd_journal_session = 0;
+
+void buffer_json_journal_versions(BUFFER *wb) {
+    buffer_json_member_add_object(wb, "versions");
+    {
+        buffer_json_member_add_uint64(wb, "sources",
+                systemd_journal_session + dictionary_version(journal_files_registry));
+    }
+    buffer_json_object_close(wb);
+}
+
+static bool journal_sd_id128_parse(const char *in, sd_id128_t *ret) {
+    while(isspace(*in))
+        in++;
+
+    char uuid[33];
+    strncpyz(uuid, in, 32);
+    uuid[32] = '\0';
+
+    if(strlen(uuid) == 32) {
+        sd_id128_t read;
+        if(sd_id128_from_string(uuid, &read) == 0) {
+            *ret = read;
+            return true;
+        }
+    }
+
+    return false;
+}
+
+static void journal_file_get_header_from_journalctl(const char *filename, struct journal_file *jf) {
+    // unfortunately, our capabilities are not inheritted by journalctl
+    // so, it fails to give us the information we need.
+
+    bool read_writer = false, read_head = false, read_tail = false;
+
+    char cmd[FILENAME_MAX * 2];
+    snprintfz(cmd, sizeof(cmd), "journalctl --header --file '%s'", filename);
+    CLEAN_BUFFER *wb = run_command_and_get_output_to_buffer(cmd, 1024);
+    if(wb) {
+        const char *s = buffer_tostring(wb);
+
+        const char *sequential_id_header = "Sequential Number ID:";
+        const char *sequential_id_data = strcasestr(s, sequential_id_header);
+        if(sequential_id_data) {
+            sequential_id_data += strlen(sequential_id_header);
+            if(journal_sd_id128_parse(sequential_id_data, &jf->first_writer_id))
+                read_writer = true;
+        }
+
+        const char *head_sequential_number_header = "Head sequential number:";
+        const char *head_sequential_number_data = strcasestr(s, head_sequential_number_header);
+        if(head_sequential_number_data) {
+            head_sequential_number_data += strlen(head_sequential_number_header);
+
+            while(isspace(*head_sequential_number_data))
+                head_sequential_number_data++;
+
+            if(isdigit(*head_sequential_number_data)) {
+                jf->first_seqnum = strtoul(head_sequential_number_data, NULL, 10);
+                if(jf->first_seqnum)
+                    read_head = true;
+            }
+        }
+
+        const char *tail_sequential_number_header = "Tail sequential number:";
+        const char *tail_sequential_number_data = strcasestr(s, tail_sequential_number_header);
+        if(tail_sequential_number_data) {
+            tail_sequential_number_data += strlen(tail_sequential_number_header);
+
+            while(isspace(*tail_sequential_number_data))
+                tail_sequential_number_data++;
+
+            if(isdigit(*tail_sequential_number_data)) {
+                jf->last_seqnum = strtoul(tail_sequential_number_data, NULL, 10);
+                if(jf->last_seqnum)
+                    read_tail = true;
+            }
+        }
+
+        if(read_head && read_tail && jf->last_seqnum > jf->first_seqnum)
+            jf->messages_in_file = jf->last_seqnum - jf->first_seqnum;
+    }
+
+    if(!jf->logged_journalctl_failure && (!read_head || !read_head || !read_tail)) {
+
+        nd_log(NDLS_COLLECTORS, NDLP_NOTICE,
+               "Failed to read %s%s%s from journalctl's output on filename '%s', using the command: %s",
+               read_writer?"":"writer id,",
+               read_head?"":"head id,",
+               read_tail?"":"tail id,",
+               filename, cmd);
+
+        jf->logged_journalctl_failure = true;
+    }
+}
+
+usec_t journal_file_update_annotation_boot_id(sd_journal *j, struct journal_file *jf, const char *boot_id) {
+    usec_t ut = UINT64_MAX;
+    int r;
+
+    char m[100];
+    size_t len = snprintfz(m, sizeof(m), "_BOOT_ID=%s", boot_id);
+
+    sd_journal_flush_matches(j);
+
+    r = sd_journal_add_match(j, m, len);
+    if(r < 0) {
+        errno = -r;
+        internal_error(true,
+                       "JOURNAL: while looking for the first timestamp of boot_id '%s', "
+                       "sd_journal_add_match('%s') on file '%s' returned %d",
+                       boot_id, m, jf->filename, r);
+        return UINT64_MAX;
+    }
+
+    r = sd_journal_seek_head(j);
+    if(r < 0) {
+        errno = -r;
+        internal_error(true,
+                       "JOURNAL: while looking for the first timestamp of boot_id '%s', "
+                       "sd_journal_seek_head() on file '%s' returned %d",
+                       boot_id, jf->filename, r);
+        return UINT64_MAX;
+    }
+
+    r = sd_journal_next(j);
+    if(r < 0) {
+        errno = -r;
+        internal_error(true,
+                       "JOURNAL: while looking for the first timestamp of boot_id '%s', "
+                       "sd_journal_next() on file '%s' returned %d",
+                       boot_id, jf->filename, r);
+        return UINT64_MAX;
+    }
+
+    r = sd_journal_get_realtime_usec(j, &ut);
+    if(r < 0 || !ut || ut == UINT64_MAX) {
+        errno = -r;
+        internal_error(r != -EADDRNOTAVAIL,
+                       "JOURNAL: while looking for the first timestamp of boot_id '%s', "
+                       "sd_journal_get_realtime_usec() on file '%s' returned %d",
+                       boot_id, jf->filename, r);
+        return UINT64_MAX;
+    }
+
+    if(ut && ut != UINT64_MAX) {
+        dictionary_set(boot_ids_to_first_ut, boot_id, &ut, sizeof(ut));
+        return ut;
+    }
+
+    return UINT64_MAX;
+}
+
+static void journal_file_get_boot_id_annotations(sd_journal *j __maybe_unused, struct journal_file *jf __maybe_unused) {
+#ifdef HAVE_SD_JOURNAL_RESTART_FIELDS
+    sd_journal_flush_matches(j);
+
+    int r = sd_journal_query_unique(j, "_BOOT_ID");
+    if (r < 0) {
+        errno = -r;
+        internal_error(true,
+                       "JOURNAL: while querying for the unique _BOOT_ID values, "
+                       "sd_journal_query_unique() on file '%s' returned %d",
+                       jf->filename, r);
+        errno = -r;
+        return;
+    }
+
+    const void *data = NULL;
+    size_t data_length;
+
+    DICTIONARY *dict = dictionary_create(DICT_OPTION_SINGLE_THREADED);
+
+    SD_JOURNAL_FOREACH_UNIQUE(j, data, data_length) {
+        const char *key, *value;
+        size_t key_length, value_length;
+
+        if(!parse_journal_field(data, data_length, &key, &key_length, &value, &value_length))
+            continue;
+
+        if(value_length != 32)
+            continue;
+
+        char buf[33];
+        memcpy(buf, value, 32);
+        buf[32] = '\0';
+
+        dictionary_set(dict, buf, NULL, 0);
+    }
+
+    void *nothing;
+    dfe_start_read(dict, nothing){
+        journal_file_update_annotation_boot_id(j, jf, nothing_dfe.name);
+    }
+    dfe_done(nothing);
+
+    dictionary_destroy(dict);
+#endif
+}
+
+void journal_file_update_header(const char *filename, struct journal_file *jf) {
+    if(jf->last_scan_header_vs_last_modified_ut == jf->file_last_modified_ut)
+        return;
+
+    fstat_cache_enable_on_thread();
+
+    const char *files[2] = {
+            [0] = filename,
+            [1] = NULL,
+    };
+
+    sd_journal *j = NULL;
+    if(sd_journal_open_files(&j, files, ND_SD_JOURNAL_OPEN_FLAGS) < 0 || !j) {
+        netdata_log_error("JOURNAL: cannot open file '%s' to update msg_ut", filename);
+        fstat_cache_disable_on_thread();
+
+        if(!jf->logged_failure) {
+            netdata_log_error("cannot open journal file '%s', using file timestamps to understand time-frame.", filename);
+            jf->logged_failure = true;
+        }
+
+        jf->msg_first_ut = 0;
+        jf->msg_last_ut = jf->file_last_modified_ut;
+        jf->last_scan_header_vs_last_modified_ut = jf->file_last_modified_ut;
+        return;
+    }
+
+    usec_t first_ut = 0, last_ut = 0;
+    uint64_t first_seqnum = 0, last_seqnum = 0;
+    sd_id128_t first_writer_id = SD_ID128_NULL, last_writer_id = SD_ID128_NULL;
+
+    if(sd_journal_seek_head(j) < 0 || sd_journal_next(j) < 0 || sd_journal_get_realtime_usec(j, &first_ut) < 0 || !first_ut) {
+        internal_error(true, "cannot find the timestamp of the first message in '%s'", filename);
+        first_ut = 0;
+    }
+#ifdef HAVE_SD_JOURNAL_GET_SEQNUM
+    else {
+        if(sd_journal_get_seqnum(j, &first_seqnum, &first_writer_id) < 0 || !first_seqnum) {
+            internal_error(true, "cannot find the first seqnums of the first message in '%s'", filename);
+            first_seqnum = 0;
+            memset(&first_writer_id, 0, sizeof(first_writer_id));
+        }
+    }
+#endif
+
+    if(sd_journal_seek_tail(j) < 0 || sd_journal_previous(j) < 0 || sd_journal_get_realtime_usec(j, &last_ut) < 0 || !last_ut) {
+        internal_error(true, "cannot find the timestamp of the last message in '%s'", filename);
+        last_ut = jf->file_last_modified_ut;
+    }
+#ifdef HAVE_SD_JOURNAL_GET_SEQNUM
+    else {
+        if(sd_journal_get_seqnum(j, &last_seqnum, &last_writer_id) < 0 || !last_seqnum) {
+            internal_error(true, "cannot find the last seqnums of the first message in '%s'", filename);
+            last_seqnum = 0;
+            memset(&last_writer_id, 0, sizeof(last_writer_id));
+        }
+    }
+#endif
+
+    if(first_ut > last_ut) {
+        internal_error(true, "timestamps are flipped in file '%s'", filename);
+        usec_t t = first_ut;
+        first_ut = last_ut;
+        last_ut = t;
+    }
+
+    if(!first_seqnum || !first_ut) {
+        // extract these from the filename - if possible
+
+        const char *at = strchr(filename, '@');
+        if(at) {
+            const char *dash_seqnum = strchr(at + 1, '-');
+            if(dash_seqnum) {
+                const char *dash_first_msg_ut = strchr(dash_seqnum + 1, '-');
+                if(dash_first_msg_ut) {
+                    const char *dot_journal = strstr(dash_first_msg_ut + 1, ".journal");
+                    if(dot_journal) {
+                        if(dash_seqnum - at - 1 == 32 &&
+                            dash_first_msg_ut - dash_seqnum - 1 == 16 &&
+                            dot_journal - dash_first_msg_ut - 1 == 16) {
+                            sd_id128_t writer;
+                            if(journal_sd_id128_parse(at + 1, &writer)) {
+                                char *endptr = NULL;
+                                uint64_t seqnum = strtoul(dash_seqnum + 1, &endptr, 16);
+                                if(endptr == dash_first_msg_ut) {
+                                    uint64_t ts = strtoul(dash_first_msg_ut + 1, &endptr, 16);
+                                    if(endptr == dot_journal) {
+                                        first_seqnum = seqnum;
+                                        first_writer_id = writer;
+                                        first_ut = ts;
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    jf->first_seqnum = first_seqnum;
+    jf->last_seqnum = last_seqnum;
+
+    jf->first_writer_id = first_writer_id;
+    jf->last_writer_id = last_writer_id;
+
+    jf->msg_first_ut = first_ut;
+    jf->msg_last_ut = last_ut;
+
+    if(!jf->msg_last_ut)
+        jf->msg_last_ut = jf->file_last_modified_ut;
+
+    if(last_seqnum > first_seqnum) {
+        if(!sd_id128_equal(first_writer_id, last_writer_id)) {
+            jf->messages_in_file = 0;
+            nd_log(NDLS_COLLECTORS, NDLP_NOTICE,
+                    "The writers of the first and the last message in file '%s' differ."
+                   , filename);
+        }
+        else
+            jf->messages_in_file = last_seqnum - first_seqnum + 1;
+    }
+    else
+        jf->messages_in_file = 0;
+
+//    if(!jf->messages_in_file)
+//        journal_file_get_header_from_journalctl(filename, jf);
+
+    journal_file_get_boot_id_annotations(j, jf);
+    sd_journal_close(j);
+    fstat_cache_disable_on_thread();
+
+    jf->last_scan_header_vs_last_modified_ut = jf->file_last_modified_ut;
+
+    nd_log(NDLS_COLLECTORS, NDLP_DEBUG,
+           "Journal file header updated '%s'",
+           jf->filename);
+}
+
+static STRING *string_strdupz_source(const char *s, const char *e, size_t max_len, const char *prefix) {
+    char buf[max_len];
+    size_t len;
+    char *dst = buf;
+
+    if(prefix) {
+        len = strlen(prefix);
+        memcpy(buf, prefix, len);
+        dst = &buf[len];
+        max_len -= len;
+    }
+
+    len = e - s;
+    if(len >= max_len)
+        len = max_len - 1;
+    memcpy(dst, s, len);
+    dst[len] = '\0';
+    buf[max_len - 1] = '\0';
+
+    for(size_t i = 0; buf[i] ;i++)
+        if(!isalnum(buf[i]) && buf[i] != '-' && buf[i] != '.' && buf[i] != ':')
+            buf[i] = '_';
+
+    return string_strdupz(buf);
+}
+
+static void files_registry_insert_cb(const DICTIONARY_ITEM *item, void *value, void *data __maybe_unused) {
+    struct journal_file *jf = value;
+    jf->filename = dictionary_acquired_item_name(item);
+    jf->filename_len = strlen(jf->filename);
+    jf->source_type = SDJF_ALL;
+
+    // based on the filename
+    // decide the source to show to the user
+    const char *s = strrchr(jf->filename, '/');
+    if(s) {
+        if(strstr(jf->filename, "/remote/")) {
+            jf->source_type |= SDJF_REMOTE_ALL;
+
+            if(strncmp(s, "/remote-", 8) == 0) {
+                s = &s[8]; // skip "/remote-"
+
+                char *e = strchr(s, '@');
+                if(!e)
+                    e = strstr(s, ".journal");
+
+                if(e) {
+                    const char *d = s;
+                    for(; d < e && (isdigit(*d) || *d == '.' || *d == ':') ; d++) ;
+                    if(d == e) {
+                        // a valid IP address
+                        char ip[e - s + 1];
+                        memcpy(ip, s, e - s);
+                        ip[e - s] = '\0';
+                        char buf[SYSTEMD_JOURNAL_MAX_SOURCE_LEN];
+                        if(ip_to_hostname(ip, buf, sizeof(buf)))
+                            jf->source = string_strdupz_source(buf, &buf[strlen(buf)], SYSTEMD_JOURNAL_MAX_SOURCE_LEN, "remote-");
+                        else {
+                            internal_error(true, "Cannot find the hostname for IP '%s'", ip);
+                            jf->source = string_strdupz_source(s, e, SYSTEMD_JOURNAL_MAX_SOURCE_LEN, "remote-");
+                        }
+                    }
+                    else
+                        jf->source = string_strdupz_source(s, e, SYSTEMD_JOURNAL_MAX_SOURCE_LEN, "remote-");
+                }
+            }
+        }
+        else {
+            jf->source_type |= SDJF_LOCAL_ALL;
+
+            const char *t = s - 1;
+            while(t >= jf->filename && *t != '.' && *t != '/')
+                t--;
+
+            if(t >= jf->filename && *t == '.') {
+                jf->source_type |= SDJF_LOCAL_NAMESPACE;
+                jf->source = string_strdupz_source(t + 1, s, SYSTEMD_JOURNAL_MAX_SOURCE_LEN, "namespace-");
+            }
+            else if(strncmp(s, "/system", 7) == 0)
+                jf->source_type |= SDJF_LOCAL_SYSTEM;
+
+            else if(strncmp(s, "/user", 5) == 0)
+                jf->source_type |= SDJF_LOCAL_USER;
+
+            else
+                jf->source_type |= SDJF_LOCAL_OTHER;
+        }
+    }
+    else
+        jf->source_type |= SDJF_LOCAL_ALL | SDJF_LOCAL_OTHER;
+
+    jf->msg_last_ut = jf->file_last_modified_ut;
+
+    nd_log(NDLS_COLLECTORS, NDLP_DEBUG,
+           "Journal file added to the journal files registry: '%s'",
+           jf->filename);
+}
+
+static bool files_registry_conflict_cb(const DICTIONARY_ITEM *item, void *old_value, void *new_value, void *data __maybe_unused) {
+    struct journal_file *jf = old_value;
+    struct journal_file *njf = new_value;
+
+    if(njf->last_scan_monotonic_ut > jf->last_scan_monotonic_ut)
+        jf->last_scan_monotonic_ut = njf->last_scan_monotonic_ut;
+
+    if(njf->file_last_modified_ut > jf->file_last_modified_ut) {
+        jf->file_last_modified_ut = njf->file_last_modified_ut;
+        jf->size = njf->size;
+
+        jf->msg_last_ut = jf->file_last_modified_ut;
+
+        nd_log(NDLS_COLLECTORS, NDLP_DEBUG,
+               "Journal file updated to the journal files registry '%s'",
+               jf->filename);
+    }
+
+    return false;
+}
+
+struct journal_file_source {
+    usec_t first_ut;
+    usec_t last_ut;
+    size_t count;
+    uint64_t size;
+};
+
+static void human_readable_size_ib(uint64_t size, char *dst, size_t dst_len) {
+    if(size > 1024ULL * 1024 * 1024 * 1024)
+        snprintfz(dst, dst_len, "%0.2f TiB", (double)size / 1024.0 / 1024.0 / 1024.0 / 1024.0);
+    else if(size > 1024ULL * 1024 * 1024)
+        snprintfz(dst, dst_len, "%0.2f GiB", (double)size / 1024.0 / 1024.0 / 1024.0);
+    else if(size > 1024ULL * 1024)
+        snprintfz(dst, dst_len, "%0.2f MiB", (double)size / 1024.0 / 1024.0);
+    else if(size > 1024ULL)
+        snprintfz(dst, dst_len, "%0.2f KiB", (double)size / 1024.0);
+    else
+        snprintfz(dst, dst_len, "%"PRIu64" B", size);
+}
+
+#define print_duration(dst, dst_len, pos, remaining, duration, one, many, printed) do { \
+    if((remaining) > (duration)) {                                                      \
+        uint64_t _count = (remaining) / (duration);                                     \
+        uint64_t _rem = (remaining) - (_count * (duration));                            \
+        (pos) += snprintfz(&(dst)[pos], (dst_len) - (pos), "%s%s%"PRIu64" %s", (printed) ? ", " : "", _rem ? "" : "and ", _count, _count > 1 ? (many) : (one));  \
+        (remaining) = _rem;                                                             \
+        (printed) = true;                                                               \
+    } \
+} while(0)
+
+static void human_readable_duration_s(time_t duration_s, char *dst, size_t dst_len) {
+    if(duration_s < 0)
+        duration_s = -duration_s;
+
+    size_t pos = 0;
+    dst[0] = 0 ;
+
+    bool printed = false;
+    print_duration(dst, dst_len, pos, duration_s, 86400 * 365, "year", "years", printed);
+    print_duration(dst, dst_len, pos, duration_s, 86400 * 30, "month", "months", printed);
+    print_duration(dst, dst_len, pos, duration_s, 86400 * 1, "day", "days", printed);
+    print_duration(dst, dst_len, pos, duration_s, 3600 * 1, "hour", "hours", printed);
+    print_duration(dst, dst_len, pos, duration_s, 60 * 1, "min", "mins", printed);
+    print_duration(dst, dst_len, pos, duration_s, 1, "sec", "secs", printed);
+}
+
+static int journal_file_to_json_array_cb(const DICTIONARY_ITEM *item, void *entry, void *data) {
+    struct journal_file_source *jfs = entry;
+    BUFFER *wb = data;
+
+    const char *name = dictionary_acquired_item_name(item);
+
+    buffer_json_add_array_item_object(wb);
+    {
+        char size_for_humans[100];
+        human_readable_size_ib(jfs->size, size_for_humans, sizeof(size_for_humans));
+
+        char duration_for_humans[1024];
+        human_readable_duration_s((time_t)((jfs->last_ut - jfs->first_ut) / USEC_PER_SEC),
+                duration_for_humans, sizeof(duration_for_humans));
+
+        char info[1024];
+        snprintfz(info, sizeof(info), "%zu files, with a total size of %s, covering %s",
+                jfs->count, size_for_humans, duration_for_humans);
+
+        buffer_json_member_add_string(wb, "id", name);
+        buffer_json_member_add_string(wb, "name", name);
+        buffer_json_member_add_string(wb, "pill", size_for_humans);
+        buffer_json_member_add_string(wb, "info", info);
+    }
+    buffer_json_object_close(wb); // options object
+
+    return 1;
+}
+
+static bool journal_file_merge_sizes(const DICTIONARY_ITEM *item __maybe_unused, void *old_value, void *new_value , void *data __maybe_unused) {
+    struct journal_file_source *jfs = old_value, *njfs = new_value;
+    jfs->count += njfs->count;
+    jfs->size += njfs->size;
+
+    if(njfs->first_ut && njfs->first_ut < jfs->first_ut)
+        jfs->first_ut = njfs->first_ut;
+
+    if(njfs->last_ut && njfs->last_ut > jfs->last_ut)
+        jfs->last_ut = njfs->last_ut;
+
+    return false;
+}
+
+void available_journal_file_sources_to_json_array(BUFFER *wb) {
+    DICTIONARY *dict = dictionary_create(DICT_OPTION_SINGLE_THREADED|DICT_OPTION_NAME_LINK_DONT_CLONE|DICT_OPTION_DONT_OVERWRITE_VALUE);
+    dictionary_register_conflict_callback(dict, journal_file_merge_sizes, NULL);
+
+    struct journal_file_source t = { 0 };
+
+    struct journal_file *jf;
+    dfe_start_read(journal_files_registry, jf) {
+        t.first_ut = jf->msg_first_ut;
+        t.last_ut = jf->msg_last_ut;
+        t.count = 1;
+        t.size = jf->size;
+
+        dictionary_set(dict, SDJF_SOURCE_ALL_NAME, &t, sizeof(t));
+
+        if(jf->source_type & SDJF_LOCAL_ALL)
+            dictionary_set(dict, SDJF_SOURCE_LOCAL_NAME, &t, sizeof(t));
+        if(jf->source_type & SDJF_LOCAL_SYSTEM)
+            dictionary_set(dict, SDJF_SOURCE_LOCAL_SYSTEM_NAME, &t, sizeof(t));
+        if(jf->source_type & SDJF_LOCAL_USER)
+            dictionary_set(dict, SDJF_SOURCE_LOCAL_USERS_NAME, &t, sizeof(t));
+        if(jf->source_type & SDJF_LOCAL_OTHER)
+            dictionary_set(dict, SDJF_SOURCE_LOCAL_OTHER_NAME, &t, sizeof(t));
+        if(jf->source_type & SDJF_LOCAL_NAMESPACE)
+            dictionary_set(dict, SDJF_SOURCE_NAMESPACES_NAME, &t, sizeof(t));
+        if(jf->source_type & SDJF_REMOTE_ALL)
+            dictionary_set(dict, SDJF_SOURCE_REMOTES_NAME, &t, sizeof(t));
+        if(jf->source)
+            dictionary_set(dict, string2str(jf->source), &t, sizeof(t));
+    }
+    dfe_done(jf);
+
+    dictionary_sorted_walkthrough_read(dict, journal_file_to_json_array_cb, wb);
+
+    dictionary_destroy(dict);
+}
+
+static void files_registry_delete_cb(const DICTIONARY_ITEM *item, void *value, void *data __maybe_unused) {
+    struct journal_file *jf = value; (void)jf;
+    const char *filename = dictionary_acquired_item_name(item); (void)filename;
+
+    internal_error(true, "removed journal file '%s'", filename);
+    string_freez(jf->source);
+}
+
+void journal_directory_scan_recursively(DICTIONARY *files, DICTIONARY *dirs, const char *dirname, int depth) {
+    static const char *ext = ".journal";
+    static const ssize_t ext_len = sizeof(".journal") - 1;
+
+    if (depth > VAR_LOG_JOURNAL_MAX_DEPTH)
+        return;
+
+    DIR *dir;
+    struct dirent *entry;
+    char full_path[FILENAME_MAX];
+
+    // Open the directory.
+    if ((dir = opendir(dirname)) == NULL) {
+        if(errno != ENOENT && errno != ENOTDIR)
+            netdata_log_error("Cannot opendir() '%s'", dirname);
+        return;
+    }
+
+    bool existing = false;
+    bool *found = dictionary_set(dirs, dirname, &existing, sizeof(existing));
+    if(*found) return;
+    *found = true;
+
+    // Read each entry in the directory.
+    while ((entry = readdir(dir)) != NULL) {
+        if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
+            continue;
+
+        ssize_t len = snprintfz(full_path, sizeof(full_path), "%s/%s", dirname, entry->d_name);
+
+        if (entry->d_type == DT_DIR) {
+            journal_directory_scan_recursively(files, dirs, full_path, depth++);
+        }
+        else if (entry->d_type == DT_REG && len > ext_len && strcmp(full_path + len - ext_len, ext) == 0) {
+            if(files)
+                dictionary_set(files, full_path, NULL, 0);
+
+            send_newline_and_flush();
+        }
+        else if (entry->d_type == DT_LNK) {
+            struct stat info;
+            if (stat(full_path, &info) == -1)
+                continue;
+
+            if (S_ISDIR(info.st_mode)) {
+                // The symbolic link points to a directory
+                char resolved_path[FILENAME_MAX + 1];
+                if (realpath(full_path, resolved_path) != NULL) {
+                    journal_directory_scan_recursively(files, dirs, resolved_path, depth++);
+                }
+            }
+            else if(S_ISREG(info.st_mode) && len > ext_len && strcmp(full_path + len - ext_len, ext) == 0) {
+                if(files)
+                    dictionary_set(files, full_path, NULL, 0);
+
+                send_newline_and_flush();
+            }
+        }
+    }
+
+    closedir(dir);
+}
+
+static size_t journal_files_scans = 0;
+bool journal_files_completed_once(void) {
+    return journal_files_scans > 0;
+}
+
+int filenames_compar(const void *a, const void *b) {
+    const char *p1 = *(const char **)a;
+    const char *p2 = *(const char **)b;
+
+    const char *at1 = strchr(p1, '@');
+    const char *at2 = strchr(p2, '@');
+
+    if(!at1 && at2)
+        return -1;
+
+    if(at1 && !at2)
+        return 1;
+
+    if(!at1 && !at2)
+        return strcmp(p1, p2);
+
+    const char *dash1 = strrchr(at1, '-');
+    const char *dash2 = strrchr(at2, '-');
+
+    if(!dash1 || !dash2)
+        return strcmp(p1, p2);
+
+    uint64_t ts1 = strtoul(dash1 + 1, NULL, 16);
+    uint64_t ts2 = strtoul(dash2 + 1, NULL, 16);
+
+    if(ts1 > ts2)
+        return -1;
+
+    if(ts1 < ts2)
+        return 1;
+
+    return -strcmp(p1, p2);
+}
+
+void journal_files_registry_update(void) {
+    static SPINLOCK spinlock = NETDATA_SPINLOCK_INITIALIZER;
+
+    if(spinlock_trylock(&spinlock)) {
+        usec_t scan_monotonic_ut = now_monotonic_usec();
+
+        DICTIONARY *files = dictionary_create(DICT_OPTION_SINGLE_THREADED | DICT_OPTION_DONT_OVERWRITE_VALUE);
+        DICTIONARY *dirs = dictionary_create(DICT_OPTION_SINGLE_THREADED|DICT_OPTION_DONT_OVERWRITE_VALUE);
+
+        for(unsigned i = 0; i < MAX_JOURNAL_DIRECTORIES; i++) {
+            if(!journal_directories[i].path) break;
+            journal_directory_scan_recursively(files, dirs, journal_directories[i].path, 0);
+        }
+
+        const char **array = mallocz(sizeof(const char *) * dictionary_entries(files));
+        size_t used = 0;
+
+        void *x;
+        dfe_start_read(files, x) {
+            if(used >= dictionary_entries(files)) continue;
+            array[used++] = x_dfe.name;
+        }
+        dfe_done(x);
+
+        qsort(array, used, sizeof(const char *), filenames_compar);
+
+        for(size_t i = 0; i < used ;i++) {
+            const char *full_path = array[i];
+
+            struct stat info;
+            if (stat(full_path, &info) == -1)
+                continue;
+
+            struct journal_file t = {
+                    .file_last_modified_ut = info.st_mtim.tv_sec * USEC_PER_SEC + info.st_mtim.tv_nsec / NSEC_PER_USEC,
+                    .last_scan_monotonic_ut = scan_monotonic_ut,
+                    .size = info.st_size,
+                    .max_journal_vs_realtime_delta_ut = JOURNAL_VS_REALTIME_DELTA_DEFAULT_UT,
+            };
+            struct journal_file *jf = dictionary_set(journal_files_registry, full_path, &t, sizeof(t));
+            journal_file_update_header(jf->filename, jf);
+        }
+        freez(array);
+        dictionary_destroy(files);
+        dictionary_destroy(dirs);
+
+        struct journal_file *jf;
+        dfe_start_write(journal_files_registry, jf){
+            if(jf->last_scan_monotonic_ut < scan_monotonic_ut)
+                dictionary_del(journal_files_registry, jf_dfe.name);
+        }
+        dfe_done(jf);
+
+        journal_files_scans++;
+        spinlock_unlock(&spinlock);
+
+        internal_error(true,
+               "Journal library scan completed in %.3f ms",
+                       (double)(now_monotonic_usec() - scan_monotonic_ut) / (double)USEC_PER_MS);
+    }
+}
+
+// ----------------------------------------------------------------------------
+
+int journal_file_dict_items_backward_compar(const void *a, const void *b) {
+    const DICTIONARY_ITEM **ad = (const DICTIONARY_ITEM **)a, **bd = (const DICTIONARY_ITEM **)b;
+    struct journal_file *jfa = dictionary_acquired_item_value(*ad);
+    struct journal_file *jfb = dictionary_acquired_item_value(*bd);
+
+    // compare the last message timestamps
+    if(jfa->msg_last_ut < jfb->msg_last_ut)
+        return 1;
+
+    if(jfa->msg_last_ut > jfb->msg_last_ut)
+        return -1;
+
+    // compare the file last modification timestamps
+    if(jfa->file_last_modified_ut < jfb->file_last_modified_ut)
+        return 1;
+
+    if(jfa->file_last_modified_ut > jfb->file_last_modified_ut)
+        return -1;
+
+    // compare the first message timestamps
+    if(jfa->msg_first_ut < jfb->msg_first_ut)
+        return 1;
+
+    if(jfa->msg_first_ut > jfb->msg_first_ut)
+        return -1;
+
+    return 0;
+}
+
+int journal_file_dict_items_forward_compar(const void *a, const void *b) {
+    return -journal_file_dict_items_backward_compar(a, b);
+}
+
+static bool boot_id_conflict_cb(const DICTIONARY_ITEM *item, void *old_value, void *new_value, void *data __maybe_unused) {
+    usec_t *old_usec = old_value;
+    usec_t *new_usec = new_value;
+
+    if(*new_usec < *old_usec) {
+        *old_usec = *new_usec;
+        return true;
+    }
+
+    return false;
+}
+
+void journal_init_files_and_directories(void) {
+    unsigned d = 0;
+
+    // ------------------------------------------------------------------------
+    // setup the journal directories
+
+    journal_directories[d++].path = strdupz("/run/log/journal");
+    journal_directories[d++].path = strdupz("/var/log/journal");
+
+    if(*netdata_configured_host_prefix) {
+        char path[PATH_MAX];
+        snprintfz(path, sizeof(path), "%s/var/log/journal", netdata_configured_host_prefix);
+        journal_directories[d++].path = strdupz(path);
+        snprintfz(path, sizeof(path), "%s/run/log/journal", netdata_configured_host_prefix);
+        journal_directories[d++].path = strdupz(path);
+    }
+
+    // terminate the list
+    journal_directories[d].path = NULL;
+
+    // ------------------------------------------------------------------------
+    // initialize the used hashes files registry
+
+    used_hashes_registry = dictionary_create(DICT_OPTION_DONT_OVERWRITE_VALUE);
+
+    systemd_journal_session = (now_realtime_usec() / USEC_PER_SEC) * USEC_PER_SEC;
+
+    journal_files_registry = dictionary_create_advanced(
+            DICT_OPTION_DONT_OVERWRITE_VALUE | DICT_OPTION_FIXED_SIZE,
+            NULL, sizeof(struct journal_file));
+
+    dictionary_register_insert_callback(journal_files_registry, files_registry_insert_cb, NULL);
+    dictionary_register_delete_callback(journal_files_registry, files_registry_delete_cb, NULL);
+    dictionary_register_conflict_callback(journal_files_registry, files_registry_conflict_cb, NULL);
+
+    boot_ids_to_first_ut = dictionary_create_advanced(
+            DICT_OPTION_DONT_OVERWRITE_VALUE | DICT_OPTION_FIXED_SIZE,
+            NULL, sizeof(usec_t));
+
+    dictionary_register_conflict_callback(boot_ids_to_first_ut, boot_id_conflict_cb, NULL);
+
+}