text: /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
  
  /*  Fluent Bit
   *  ==========
   *  Copyright (C) 2019-2021 The Fluent Bit Authors
   *  Copyright (C) 2015-2018 Treasure Data Inc.
   *
   *  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 <fluent-bit/flb_utils.h>
  #include <fluent-bit/flb_time.h>
  #include <fluent-bit/flb_pack.h>
  #include <fluent-bit/flb_sds.h>
  #include <fluent-bit/flb_http_client.h>
  #include <fluent-bit/flb_config_map.h>
  #include <msgpack.h>
  
  #include "kafka.h"
  #include "kafka_conf.h"
  
  static struct flb_config_map config_map[] = {
      {
       FLB_CONFIG_MAP_STR, "message_key", NULL,
       0, FLB_TRUE, offsetof(struct flb_kafka_rest, message_key),
       "Specify a message key. "
      },
  
      {
       FLB_CONFIG_MAP_STR, "time_key", NULL,
       0, FLB_TRUE, offsetof(struct flb_kafka_rest, time_key),
       "Specify the name of the field that holds the record timestamp. "
      },
  
      {
       FLB_CONFIG_MAP_STR, "topic", "fluent-bit",
       0, FLB_TRUE, offsetof(struct flb_kafka_rest, topic),
       "Specify the kafka topic. "
      },
  
      {
       FLB_CONFIG_MAP_STR, "url_path", NULL,
       0, FLB_TRUE, offsetof(struct flb_kafka_rest, url_path),
       "Specify an optional HTTP URL path for the target web server, e.g: /something"
      },
  
      {
       FLB_CONFIG_MAP_DOUBLE, "partition", "-1",
       0, FLB_TRUE, offsetof(struct flb_kafka_rest, partition),
       "Specify kafka partition number. "
      },
  
      {
       FLB_CONFIG_MAP_STR, "time_key_format", FLB_KAFKA_TIME_KEYF,
       0, FLB_TRUE, offsetof(struct flb_kafka_rest, time_key_format),
       "Specify the format of the timestamp. "
      },
  
      {
       FLB_CONFIG_MAP_BOOL, "include_tag_key", "false",
       0, FLB_TRUE, offsetof(struct flb_kafka_rest, include_tag_key),
       "Specify whether to append tag name to final record. "
      },
  
      {
       FLB_CONFIG_MAP_STR, "tag_key", "_flb-key",
       0, FLB_TRUE, offsetof(struct flb_kafka_rest, tag_key),
       "Specify the key name of the record if include_tag_key is enabled. "
      },
  
      /* EOF */
      {0}
  };
  /*
   * Convert the internal Fluent Bit data representation to the required
   * one by Kafka REST Proxy.
   */
  static flb_sds_t kafka_rest_format(const void *data, size_t bytes,
                                     const char *tag, int tag_len,
                                     size_t *out_size,
                                     struct flb_kafka_rest *ctx)
  {
      int i;
      int len;
      int arr_size = 0;
      int map_size;
      size_t s;
      size_t off = 0;
      flb_sds_t out_buf;
      char time_formatted[256];
      msgpack_unpacked result;
      msgpack_object root;
      msgpack_object map;
      msgpack_object *obj;
      msgpack_object key;
      msgpack_object val;
      struct tm tm;
      struct flb_time tms;
      msgpack_sbuffer mp_sbuf;
      msgpack_packer mp_pck;
  
      /* Init temporary buffers */
      msgpack_sbuffer_init(&mp_sbuf);
      msgpack_packer_init(&mp_pck, &mp_sbuf, msgpack_sbuffer_write);
  
      /* Iterate the original buffer and perform adjustments */
      msgpack_unpacked_init(&result);
  
      /* Count number of entries */
      while (msgpack_unpack_next(&result, data, bytes, &off) == MSGPACK_UNPACK_SUCCESS) {
          arr_size++;
      }
      msgpack_unpacked_destroy(&result);
      off = 0;
  
      /* Root map */
      msgpack_pack_map(&mp_pck, 1);
      msgpack_pack_str(&mp_pck, 7);
      msgpack_pack_str_body(&mp_pck, "records", 7);
  
      msgpack_pack_array(&mp_pck, arr_size);
  
      /* Iterate and compose array content */
      msgpack_unpacked_init(&result);
      while (msgpack_unpack_next(&result, data, bytes, &off) == MSGPACK_UNPACK_SUCCESS) {
          root = result.data;
  
          map = root.via.array.ptr[1];
          map_size = 1;
  
          flb_time_pop_from_msgpack(&tms, &result, &obj);
  
          if (ctx->partition >= 0) {
              map_size++;
          }
  
          if (ctx->message_key != NULL) {
              map_size++;
          }
  
          msgpack_pack_map(&mp_pck, map_size);
          if (ctx->partition >= 0) {
              msgpack_pack_str(&mp_pck, 9);
              msgpack_pack_str_body(&mp_pck, "partition", 9);
              msgpack_pack_int64(&mp_pck, ctx->partition);
          }
  
  
          if (ctx->message_key != NULL) {
              msgpack_pack_str(&mp_pck, 3);
              msgpack_pack_str_body(&mp_pck, "key", 3);
              msgpack_pack_str(&mp_pck, ctx->message_key_len);
              msgpack_pack_str_body(&mp_pck, ctx->message_key, ctx->message_key_len);
          }
  
          /* Value Map Size */
          map_size = map.via.map.size;
          map_size++;
          if (ctx->include_tag_key == FLB_TRUE) {
              map_size++;
          }
  
          msgpack_pack_str(&mp_pck, 5);
          msgpack_pack_str_body(&mp_pck, "value", 5);
  
          msgpack_pack_map(&mp_pck, map_size);
  
          /* Time key and time formatted */
          msgpack_pack_str(&mp_pck, ctx->time_key_len);
          msgpack_pack_str_body(&mp_pck, ctx->time_key, ctx->time_key_len);
  
          /* Format the time */
          gmtime_r(&tms.tm.tv_sec, &tm);
          s = strftime(time_formatted, sizeof(time_formatted) - 1,
                       ctx->time_key_format, &tm);
          len = snprintf(time_formatted + s, sizeof(time_formatted) - 1 - s,
                         ".%09" PRIu64 "Z", (uint64_t) tms.tm.tv_nsec);
          s += len;
          msgpack_pack_str(&mp_pck, s);
          msgpack_pack_str_body(&mp_pck, time_formatted, s);
  
          /* Tag Key */
          if (ctx->include_tag_key == FLB_TRUE) {
              msgpack_pack_str(&mp_pck, ctx->tag_key_len);
              msgpack_pack_str_body(&mp_pck, ctx->tag_key, ctx->tag_key_len);
              msgpack_pack_str(&mp_pck, tag_len);
              msgpack_pack_str_body(&mp_pck, tag, tag_len);
          }
  
          for (i = 0; i < map.via.map.size; i++) {
              key = map.via.map.ptr[i].key;
              val = map.via.map.ptr[i].val;
  
              msgpack_pack_object(&mp_pck, key);
              msgpack_pack_object(&mp_pck, val);
          }
      }
      msgpack_unpacked_destroy(&result);
  
      /* Convert to JSON */
      out_buf = flb_msgpack_raw_to_json_sds(mp_sbuf.data, mp_sbuf.size);
      msgpack_sbuffer_destroy(&mp_sbuf);
      if (!out_buf) {
          return NULL;
      }
  
      *out_size = flb_sds_len(out_buf);
      return out_buf;
  }
  
  static int cb_kafka_init(struct flb_output_instance *ins,
                           struct flb_config *config,
                           void *data)
  {
      (void) ins;
      (void) config;
      (void) data;
      struct flb_kafka_rest *ctx;
  
      ctx = flb_kr_conf_create(ins, config);
      if (!ctx) {
          flb_plg_error(ins, "cannot initialize plugin");
          return -1;
      }
  
      flb_plg_debug(ctx->ins, "host=%s port=%i",
                    ins->host.name, ins->host.port);
      flb_output_set_context(ins, ctx);
  
      return 0;
  }
  
  static void cb_kafka_flush(const void *data, size_t bytes,
                             const char *tag, int tag_len,
                             struct flb_input_instance *i_ins,
                             void *out_context,
                             struct flb_config *config)
  {
      int ret;
      flb_sds_t js;
      size_t js_size;
      size_t b_sent;
      struct flb_http_client *c;
      struct flb_upstream_conn *u_conn;
      struct flb_kafka_rest *ctx = out_context;
      (void) i_ins;
      (void) tag;
      (void) tag_len;
  
      /* Get upstream connection */
      u_conn = flb_upstream_conn_get(ctx->u);
      if (!u_conn) {
          FLB_OUTPUT_RETURN(FLB_RETRY);
      }
  
      /* Convert format */
      js = kafka_rest_format(data, bytes, tag, tag_len, &js_size, ctx);
      if (!js) {
          flb_upstream_conn_release(u_conn);
          FLB_OUTPUT_RETURN(FLB_ERROR);
      }
  
      /* Compose HTTP Client request */
      c = flb_http_client(u_conn, FLB_HTTP_POST, ctx->uri,
                          js, js_size, NULL, 0, NULL, 0);
      flb_http_add_header(c, "User-Agent", 10, "Fluent-Bit", 10);
      flb_http_add_header(c,
                          "Content-Type", 12,
                          "application/vnd.kafka.json.v2+json", 34);
  
      if (ctx->http_user && ctx->http_passwd) {
          flb_http_basic_auth(c, ctx->http_user, ctx->http_passwd);
      }
  
      ret = flb_http_do(c, &b_sent);
      if (ret != 0) {
          flb_plg_warn(ctx->ins, "http_do=%i", ret);
          goto retry;
      }
      else {
          /* The request was issued successfully, validate the 'error' field */
          flb_plg_debug(ctx->ins, "HTTP Status=%i", c->resp.status);
          if (c->resp.status != 200) {
              if (c->resp.payload_size > 0) {
                  flb_plg_debug(ctx->ins, "Kafka REST response\n%s",
                                c->resp.payload);
              }
              goto retry;
          }
  
          if (c->resp.payload_size > 0) {
              flb_plg_debug(ctx->ins, "Kafka REST response\n%s",
                            c->resp.payload);
          }
          else {
              goto retry;
          }
      }
  
      /* Cleanup */
      flb_http_client_destroy(c);
      flb_sds_destroy(js);
      flb_upstream_conn_release(u_conn);
      FLB_OUTPUT_RETURN(FLB_OK);
  
      /* Issue a retry */
   retry:
      flb_http_client_destroy(c);
      flb_sds_destroy(js);
      flb_upstream_conn_release(u_conn);
      FLB_OUTPUT_RETURN(FLB_RETRY);
  }
  
  static int cb_kafka_exit(void *data, struct flb_config *config)
  {
      struct flb_kafka_rest *ctx = data;
  
      flb_kr_conf_destroy(ctx);
      return 0;
  }
  
  struct flb_output_plugin out_kafka_rest_plugin = {
      .name         = "kafka-rest",
      .description  = "Kafka REST Proxy",
      .cb_init      = cb_kafka_init,
      .cb_flush     = cb_kafka_flush,
      .cb_exit      = cb_kafka_exit,
      .config_map   = config_map,
      .flags        = FLB_OUTPUT_NET | FLB_IO_OPT_TLS,
  };
  