5 files changed, 708 insertions, 0 deletions

diff --git a/fluent-bit/plugins/out_pgsql/CMakeLists.txt b/fluent-bit/plugins/out_pgsql/CMakeLists.txt
new file mode 100644
index 000000000..6206c02f9
--- /dev/null
+++ b/fluent-bit/plugins/out_pgsql/CMakeLists.txt
@@ -0,0 +1,8 @@
+set(src
+  pgsql.c
+  pgsql_connections.c
+  )
+
+FLB_PLUGIN(out_pgsql "${src}" "")
+target_include_directories(flb-plugin-out_pgsql PRIVATE ${PostgreSQL_INCLUDE_DIRS})
+target_link_libraries(flb-plugin-out_pgsql -lpq)
diff --git a/fluent-bit/plugins/out_pgsql/pgsql.c b/fluent-bit/plugins/out_pgsql/pgsql.c
new file mode 100644
index 000000000..a01090c1a
--- /dev/null
+++ b/fluent-bit/plugins/out_pgsql/pgsql.c
@@ -0,0 +1,389 @@
+/* -*- 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 <fluent-bit/flb_info.h>
+#include <fluent-bit/flb_output.h>
+#include <fluent-bit/flb_utils.h>
+#include <fluent-bit/flb_pack.h>
+
+#include "pgsql.h"
+#include "pgsql_connections.h"
+
+void pgsql_conf_destroy(struct flb_pgsql_config *ctx)
+{
+    pgsql_destroy_connections(ctx);
+
+    flb_free(ctx->db_hostname);
+
+    if (ctx->db_table != NULL) {
+        flb_sds_destroy(ctx->db_table);
+    }
+
+    if (ctx->timestamp_key != NULL) {
+        flb_sds_destroy(ctx->timestamp_key);
+    }
+
+    flb_free(ctx);
+    ctx = NULL;
+}
+
+static int cb_pgsql_init(struct flb_output_instance *ins,
+                          struct flb_config *config, void *data)
+{
+
+    struct flb_pgsql_config *ctx;
+    size_t str_len;
+    PGresult *res;
+    char *query = NULL;
+    char *temp = NULL;
+    const char *tmp = NULL;
+    int ret;
+
+    /* set default network configuration */
+    flb_output_net_default(FLB_PGSQL_HOST, FLB_PGSQL_PORT, ins);
+
+    ctx = flb_calloc(1, sizeof(struct flb_pgsql_config));
+    if (!ctx) {
+        flb_errno();
+        return -1;
+    }
+
+    ctx->ins = ins;
+
+    /* Database host */
+    ctx->db_hostname = flb_strdup(ins->host.name);
+    if (!ctx->db_hostname) {
+        flb_errno();
+        pgsql_conf_destroy(ctx);
+        return -1;
+    }
+
+    /* Database port */
+    snprintf(ctx->db_port, sizeof(ctx->db_port), "%d", ins->host.port);
+
+    /* Database name */
+    ctx->db_name = flb_output_get_property("database", ins);
+    if (!ctx->db_name) {
+        ctx->db_name = FLB_PGSQL_DBNAME;
+    }
+
+    /* db table */
+    tmp = flb_output_get_property("table", ins);
+    if (tmp) {
+        ctx->db_table = flb_sds_create(tmp);
+    }
+    else {
+        ctx->db_table = flb_sds_create(FLB_PGSQL_TABLE);
+    }
+
+    /* connection options */
+    ctx->conn_options = flb_output_get_property("connection_options", ins);
+
+    if (!ctx->db_table) {
+        flb_errno();
+        pgsql_conf_destroy(ctx);
+        return -1;
+    }
+
+    /* db user */
+    ctx->db_user = flb_output_get_property("user", ins);
+    if (!ctx->db_user) {
+        flb_plg_warn(ctx->ins,
+                     "You didn't supply a valid user to connect,"
+                     "your current unix user will be used");
+    }
+
+    /* db user password */
+    ctx->db_passwd = flb_output_get_property("password", ins);
+
+    /* timestamp key */
+    tmp = flb_output_get_property("timestamp_key", ins);
+    if (tmp) {
+        ctx->timestamp_key = flb_sds_create(tmp);
+    }
+    else {
+        ctx->timestamp_key = flb_sds_create(FLB_PGSQL_TIMESTAMP_KEY);
+    }
+
+    if (!ctx->timestamp_key) {
+        flb_errno();
+        pgsql_conf_destroy(ctx);
+        return -1;
+    }
+
+    /* Pool size */
+    tmp = flb_output_get_property("max_pool_size", ins);
+    if (tmp) {
+        ctx->max_pool_size = strtol(tmp, NULL, 0);
+        if (ctx->max_pool_size < 1)
+            ctx->max_pool_size = 1;
+    }
+    else {
+        ctx->max_pool_size = FLB_PGSQL_POOL_SIZE;
+    }
+
+    tmp = flb_output_get_property("min_pool_size", ins);
+    if (tmp) {
+        ctx->min_pool_size = strtol(tmp, NULL, 0);
+        if (ctx->min_pool_size < 1 || ctx->min_pool_size > ctx->max_pool_size)
+            ctx->min_pool_size = ctx->max_pool_size;
+    }
+    else {
+        ctx->min_pool_size = FLB_PGSQL_MIN_POOL_SIZE;
+    }
+
+    /* Sync Mode */
+    tmp = flb_output_get_property("async", ins);
+    if (tmp && flb_utils_bool(tmp)) {
+        ctx->async = FLB_TRUE;
+    }
+    else {
+        ctx->async = FLB_FALSE;
+    }
+
+    if (!ctx->async) {
+        ctx->min_pool_size = 1;
+        ctx->max_pool_size = 1;
+    }
+
+    /* CockroachDB Support */
+    tmp = flb_output_get_property("cockroachdb", ins);
+    if (tmp && flb_utils_bool(tmp)) {
+        ctx->cockroachdb = FLB_TRUE;
+    }
+    else {
+        ctx->cockroachdb = FLB_FALSE;
+    }
+
+    ret = pgsql_start_connections(ctx);
+    if (ret) {
+        return -1;
+    }
+
+    flb_plg_info(ctx->ins, "host=%s port=%s dbname=%s OK",
+              ctx->db_hostname, ctx->db_port, ctx->db_name);
+    flb_output_set_context(ins, ctx);
+
+    temp = PQescapeIdentifier(ctx->conn_current->conn, ctx->db_table,
+                              flb_sds_len(ctx->db_table));
+
+    if (temp == NULL) {
+        flb_plg_error(ctx->ins, "failed to parse table name: %s",
+                      PQerrorMessage(ctx->conn_current->conn));
+        pgsql_conf_destroy(ctx);
+        return -1;
+    }
+
+    flb_sds_destroy(ctx->db_table);
+    ctx->db_table = flb_sds_create(temp);
+    PQfreemem(temp);
+
+    if (!ctx->db_table) {
+        flb_errno();
+        pgsql_conf_destroy(ctx);
+        return -1;
+    }
+
+    flb_plg_info(ctx->ins, "we check that the table %s "
+                 "exists, if not we create it", ctx->db_table);
+
+    str_len = 72 + flb_sds_len(ctx->db_table);
+
+    query = flb_malloc(str_len);
+    if (query == NULL) {
+        flb_errno();
+        pgsql_conf_destroy(ctx);
+        return -1;
+    }
+
+    /* Maybe use the timestamp with the TZ specified */
+    /* in the postgresql connection? */
+    snprintf(query, str_len,
+             "CREATE TABLE IF NOT EXISTS %s "
+             "(tag varchar, time timestamp, data jsonb);",
+             ctx->db_table);
+    flb_plg_trace(ctx->ins, "%s", query);
+    res = PQexec(ctx->conn_current->conn, query);
+
+    flb_free(query);
+
+    if (PQresultStatus(res) != PGRES_COMMAND_OK) {
+        flb_plg_error(ctx->ins, "%s",
+                      PQerrorMessage(ctx->conn_current->conn));
+        pgsql_conf_destroy(ctx);
+        return -1;
+    }
+
+    PQclear(res);
+
+    return 0;
+}
+
+static void cb_pgsql_flush(struct flb_event_chunk *event_chunk,
+                           struct flb_output_flush *out_flush,
+                           struct flb_input_instance *i_ins,
+                           void *out_context,
+                           struct flb_config *config)
+{
+    struct flb_pgsql_config *ctx = out_context;
+    flb_sds_t json;
+    char *tmp = NULL;
+    char *query = NULL;
+    PGresult *res = NULL;
+    int send_res;
+    flb_sds_t tag_escaped = NULL;
+    size_t str_len;
+
+
+    if (pgsql_next_connection(ctx) == 1) {
+        FLB_OUTPUT_RETURN(FLB_RETRY);
+    }
+
+    /*
+     * PQreset()
+     * This function will close the connection to the server and attempt to
+     * reestablish a new connection to the same server, using all the same
+     * parameters previously used. This might be useful for error recovery
+     * if a working connection is lost.
+     */
+    if (PQstatus(ctx->conn_current->conn) != CONNECTION_OK) {
+        PQreset(ctx->conn_current->conn);
+        FLB_OUTPUT_RETURN(FLB_RETRY);
+    }
+
+    json = flb_pack_msgpack_to_json_format(event_chunk->data,
+                                           event_chunk->size,
+                                           FLB_PACK_JSON_FORMAT_JSON,
+                                           FLB_PACK_JSON_DATE_DOUBLE,
+                                           ctx->timestamp_key);
+    if (json == NULL) {
+        flb_errno();
+        flb_plg_error(ctx->ins,
+                      "Can't parse the msgpack into json");
+        FLB_OUTPUT_RETURN(FLB_RETRY);
+    }
+
+    tmp = PQescapeLiteral(ctx->conn_current->conn, json, flb_sds_len(json));
+    flb_sds_destroy(json);
+    if (!tmp) {
+        flb_errno();
+        PQfreemem(tmp);
+        flb_plg_error(ctx->ins, "Can't escape json string");
+        FLB_OUTPUT_RETURN(FLB_RETRY);
+    }
+
+    json = flb_sds_create(tmp);
+    PQfreemem(tmp);
+    if (!json) {
+        flb_errno();
+        FLB_OUTPUT_RETURN(FLB_RETRY);
+    }
+
+    tmp = PQescapeLiteral(ctx->conn_current->conn,
+                          event_chunk->tag,
+                          flb_sds_len(event_chunk->tag));
+    if (!tmp) {
+        flb_errno();
+        flb_sds_destroy(json);
+        PQfreemem(tmp);
+        flb_plg_error(ctx->ins, "Can't escape tag string: %s",
+                      event_chunk->tag);
+        FLB_OUTPUT_RETURN(FLB_RETRY);
+    }
+
+    tag_escaped = flb_sds_create(tmp);
+    PQfreemem(tmp);
+    if (!tag_escaped) {
+        flb_errno();
+        flb_sds_destroy(json);
+        FLB_OUTPUT_RETURN(FLB_RETRY);
+    }
+
+    str_len = 100 + flb_sds_len(json)
+        + flb_sds_len(tag_escaped)
+        + flb_sds_len(ctx->db_table)
+        + flb_sds_len(ctx->timestamp_key);
+    query = flb_malloc(str_len);
+
+    if (query == NULL) {
+        flb_errno();
+        flb_sds_destroy(json);
+        flb_sds_destroy(tag_escaped);
+        FLB_OUTPUT_RETURN(FLB_RETRY);
+    }
+
+
+    snprintf(query, str_len,
+             ctx->cockroachdb ? FLB_PGSQL_INSERT_COCKROACH : FLB_PGSQL_INSERT,
+             ctx->db_table, tag_escaped, ctx->timestamp_key, json);
+    flb_plg_trace(ctx->ins, "query: %s", query);
+
+    if (ctx->async) {
+        send_res = PQsendQuery(ctx->conn_current->conn, query);
+        flb_free(query);
+        flb_sds_destroy(json);
+        flb_sds_destroy(tag_escaped);
+
+        if (send_res == 0) {
+            flb_plg_error(ctx->ins, "%s",
+                          PQerrorMessage(ctx->conn_current->conn));
+            FLB_OUTPUT_RETURN(FLB_RETRY);
+        }
+
+        PQflush(ctx->conn_current->conn);
+    }
+    else {
+        res = PQexec(ctx->conn_current->conn, query);
+        flb_free(query);
+        flb_sds_destroy(json);
+        flb_sds_destroy(tag_escaped);
+
+        if (PQresultStatus(res) != PGRES_COMMAND_OK) {
+            flb_plg_error(ctx->ins, "%s",
+                          PQerrorMessage(ctx->conn_current->conn));
+            PQclear(res);
+            FLB_OUTPUT_RETURN(FLB_RETRY);
+        }
+        PQclear(res);
+    }
+
+    FLB_OUTPUT_RETURN(FLB_OK);
+}
+
+static int cb_pgsql_exit(void *data, struct flb_config *config)
+{
+    struct flb_pgsql_config *ctx = data;
+
+    if (!ctx){
+        return 0;
+    }
+
+    pgsql_conf_destroy(ctx);
+
+    return 0;
+}
+
+struct flb_output_plugin out_pgsql_plugin = {
+    .name         = "pgsql",
+    .description  = "PostgreSQL",
+    .cb_init      = cb_pgsql_init,
+    .cb_flush     = cb_pgsql_flush,
+    .cb_exit      = cb_pgsql_exit,
+    .flags        = 0,
+};
diff --git a/fluent-bit/plugins/out_pgsql/pgsql.h b/fluent-bit/plugins/out_pgsql/pgsql.h
new file mode 100644
index 000000000..5190a5a54
--- /dev/null
+++ b/fluent-bit/plugins/out_pgsql/pgsql.h
@@ -0,0 +1,91 @@
+/* -*- 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.
+ */
+
+#ifndef FLB_OUT_PGSQL_H
+#define FLB_OUT_PGSQL_H
+
+#include <fluent-bit/flb_output.h>
+#include <fluent-bit/flb_time.h>
+#include <fluent-bit/flb_output_plugin.h>
+
+#include <libpq-fe.h>
+
+#define FLB_PGSQL_HOST "127.0.0.1"
+#define FLB_PGSQL_PORT 5432
+#define FLB_PGSQL_DBNAME "fluentbit"
+#define FLB_PGSQL_TABLE "fluentbit"
+#define FLB_PGSQL_TIMESTAMP_KEY "date"
+#define FLB_PGSQL_POOL_SIZE 4
+#define FLB_PGSQL_MIN_POOL_SIZE 1
+#define FLB_PGSQL_SYNC FLB_FALSE
+#define FLB_PGSQL_COCKROACH FLB_FALSE
+
+#define FLB_PGSQL_INSERT "INSERT INTO %s SELECT %s, "   \
+    "to_timestamp(CAST(value->>'%s' as FLOAT)),"        \
+    " * FROM json_array_elements(%s);"
+#define FLB_PGSQL_INSERT_COCKROACH "INSERT INTO %s SELECT %s,"  \
+    "CAST(value->>'%s' AS INTERVAL) + DATE'1970-01-01',"        \
+    " * FROM json_array_elements(%s);"
+
+struct flb_pgsql_conn {
+    struct mk_list _head;
+    PGconn *conn;
+    int number;
+};
+
+struct flb_pgsql_config {
+
+    /* database */
+    char *db_hostname;
+    char db_port[8];
+    const char *db_name;
+    flb_sds_t db_table;
+
+    /* auth */
+    const char *db_user;
+    const char *db_passwd;
+
+    /* time key */
+    flb_sds_t timestamp_key;
+
+    /* instance reference */
+    struct flb_output_instance *ins;
+
+    /* connections options */
+    const char *conn_options;
+
+    /* connections pool */
+    struct mk_list conn_queue;
+    struct mk_list _head;
+
+    struct flb_pgsql_conn *conn_current;
+    int max_pool_size;
+    int min_pool_size;
+    int active_conn;
+
+    /* async mode or sync mode */
+    int async;
+
+    /* cockroachdb */
+    int cockroachdb;
+};
+
+void pgsql_conf_destroy(struct flb_pgsql_config *ctx);
+
+#endif
diff --git a/fluent-bit/plugins/out_pgsql/pgsql_connections.c b/fluent-bit/plugins/out_pgsql/pgsql_connections.c
new file mode 100644
index 000000000..9c4ccfba2
--- /dev/null
+++ b/fluent-bit/plugins/out_pgsql/pgsql_connections.c
@@ -0,0 +1,193 @@
+/* -*- 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 <fluent-bit/flb_output_plugin.h>
+
+#include "pgsql.h"
+
+void pgsql_destroy_connections(struct flb_pgsql_config *ctx)
+{
+    struct mk_list *tmp;
+    struct mk_list *head;
+    struct flb_pgsql_conn *conn;
+    PGresult *res = NULL;
+
+    mk_list_foreach_safe(head, tmp, &ctx->conn_queue) {
+        conn = mk_list_entry(head, struct flb_pgsql_conn, _head);
+        if (PQstatus(conn->conn) == CONNECTION_OK) {
+            while(PQconsumeInput(conn->conn) == 0) {
+                res = PQgetResult(conn->conn);
+                if (PQresultStatus(res) != PGRES_COMMAND_OK) {
+                    flb_plg_warn(ctx->ins, "%s",
+                                 PQerrorMessage(conn->conn));
+                }
+                PQclear(res);
+            }
+        }
+        PQfinish(conn->conn);
+        flb_free(conn);
+    }
+}
+
+void *pgsql_create_connection(struct flb_pgsql_config *ctx)
+{
+    struct flb_pgsql_conn *conn;
+
+    conn = flb_calloc(1, sizeof(struct flb_pgsql_conn));
+    if (!conn) {
+        flb_errno();
+        return NULL;
+    }
+
+    conn->conn = PQsetdbLogin(ctx->db_hostname,
+                              ctx->db_port,
+                              ctx->conn_options,
+                              NULL,
+                              ctx->db_name,
+                              ctx->db_user,
+                              ctx->db_passwd);
+
+    if (PQstatus(conn->conn) != CONNECTION_OK) {
+        flb_plg_error(ctx->ins,
+                      "failed connecting to host=%s with error: %s",
+                      ctx->db_hostname, PQerrorMessage(conn->conn));
+        PQfinish(conn->conn);
+        flb_free(conn);
+        return NULL;
+    }
+
+    flb_plg_info(ctx->ins, "switching postgresql connection "
+                 "to non-blocking mode");
+
+    if (PQsetnonblocking(conn->conn, 1) != 0) {
+        flb_plg_error(ctx->ins, "non-blocking mode not set");
+        PQfinish(conn->conn);
+        flb_free(conn);
+        return NULL;
+    }
+
+    return conn;
+}
+
+int pgsql_start_connections(struct flb_pgsql_config *ctx)
+{
+    int i;
+    struct flb_pgsql_conn *conn = NULL;
+
+    mk_list_init(&ctx->conn_queue);
+    ctx->active_conn = 0;
+
+    for(i = 0; i < ctx->min_pool_size; i++) {
+        flb_plg_info(ctx->ins, "Opening connection: #%d", i);
+
+        conn = (struct flb_pgsql_conn *)pgsql_create_connection(ctx);
+        if (conn == NULL) {
+            pgsql_conf_destroy(ctx);
+            return -1;
+        }
+
+        conn->number = i;
+        ctx->active_conn++;
+        mk_list_add(&conn->_head, &ctx->conn_queue);
+    }
+
+    ctx->conn_current = mk_list_entry_last(&ctx->conn_queue,
+                                           struct flb_pgsql_conn,
+                                           _head);
+
+    return 0;
+}
+
+int pgsql_new_connection(struct flb_pgsql_config *ctx)
+{
+    struct flb_pgsql_conn *conn = NULL;
+
+    if (ctx->active_conn >= ctx->max_pool_size) {
+        return -1;
+    }
+
+    conn = (struct flb_pgsql_conn *)pgsql_create_connection(ctx);
+    if (conn == NULL) {
+        pgsql_conf_destroy(ctx);
+        return -1;
+    }
+
+    conn->number = ctx->active_conn + 1;
+    ctx->active_conn++;
+
+    mk_list_add(&conn->_head, &ctx->conn_queue);
+
+    return 0;
+}
+
+int pgsql_next_connection(struct flb_pgsql_config *ctx)
+{
+    struct flb_pgsql_conn *tmp = NULL;
+    PGresult *res = NULL;
+    struct mk_list *head;
+    int ret_conn = 1;
+
+    if (PQconsumeInput(ctx->conn_current->conn) == 1) {
+        if (PQisBusy(ctx->conn_current->conn) == 0) {
+            res = PQgetResult(ctx->conn_current->conn);
+            PQclear(res);
+        }
+    }
+    else {
+        flb_plg_error(ctx->ins, "%s",
+                      PQerrorMessage(ctx->conn_current->conn));
+    }
+
+    mk_list_foreach(head, &ctx->conn_queue) {
+        tmp = mk_list_entry(head, struct flb_pgsql_conn, _head);
+        if (ctx->conn_current == NULL) {
+            ctx->conn_current = tmp;
+            break;
+        }
+
+        res = PQgetResult(tmp->conn);
+
+        if (res == NULL) {
+            flb_plg_debug(ctx->ins, "Connection number %d",
+                          tmp->number);
+            ctx->conn_current = tmp;
+            PQclear(res);
+            return 0;
+        }
+
+        if (PQresultStatus(res) == PGRES_FATAL_ERROR) {
+            flb_plg_info(ctx->ins, "%s",
+                         PQerrorMessage(tmp->conn));
+        }
+
+        PQclear(res);
+    }
+
+    if (pgsql_new_connection(ctx) == -1) {
+        flb_plg_warn(ctx->ins,
+                     "No more free connections."
+                     " Increase max connections");
+    }
+    else {
+        flb_plg_warn(ctx->ins, "Added new connection");
+        ret_conn = pgsql_next_connection(ctx);
+    }
+
+    return ret_conn;
+}
diff --git a/fluent-bit/plugins/out_pgsql/pgsql_connections.h b/fluent-bit/plugins/out_pgsql/pgsql_connections.h
new file mode 100644
index 000000000..cd8730618
--- /dev/null
+++ b/fluent-bit/plugins/out_pgsql/pgsql_connections.h
@@ -0,0 +1,27 @@
+/* -*- 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.
+ */
+
+#ifndef FLB_OUT_PGSQL_CONNECTIONS_H
+#define FLB_OUT_PGSQL_CONNECTIONS_H
+
+void pgsql_destroy_connections(struct flb_pgsql_config *ctx);
+int pgsql_start_connections(struct flb_pgsql_config *ctx);
+int pgsql_next_connection(struct flb_pgsql_config *ctx);
+
+#endif