http_client: out_es: lib: implement http client response testing mechanism

include/fluent-bit/flb_http_client.h

@@ -99,6 +99,71 @@ struct flb_http_debug {
     int (*cb_debug_request_payload);
 };
 
+/* To make opaque struct */
+struct flb_http_client;
+
+/*
+ * Tests callbacks
+ * ===============
+ */
+struct flb_test_http_response {
+    /*
+     * Response Test Mode
+     * ====================
+     * When the response test enable the test response mode, it needs to
+     * keep a reference of the context and other information:
+     *
+     * - rt_ctx : flb_http_client context
+     *
+     * - rt_status : HTTP response code
+     *
+     * - rt_in_callback: intermediary function to receive the results of
+     *                  the http response test function.
+     *
+     * - rt_data: opaque data type for rt_in_callback()
+     */
+
+    /* runtime library context */
+    void *rt_ctx;
+
+    /* HTTP status */
+    int rt_status;
+
+    /* optional response context */
+    void *response_ctx;
+
+    /*
+     * "response test callback": this function pointer is used by Fluent Bit
+     * http client testing mode to reference a test function that must retrieve the
+     * results of 'callback'. Consider this an intermediary function to
+     * transfer the results to the runtime test.
+     *
+     * This function is private and should not be set manually in the plugin
+     * code, it's set on src/flb_http_client.c .
+     */
+    void (*rt_resp_callback) (void *, int, void *, size_t, void *);
+
+    /*
+     * opaque data type passed by the runtime library to be used on
+     * rt_in_callback().
+     */
+    void *rt_data;
+
+    /*
+     * Callback
+     * =========
+     * "HTTP response callback": it references the plugin function that performs
+     * to validate HTTP response by HTTP client. This entry is mostly to
+     * expose the plugin local function.
+     */
+    int (*callback) (/* plugin that ingested the records */
+                     struct flb_http_client *,
+                     const void *,   /* incoming response data */
+                     size_t,         /* incoming response size */
+                     void **,        /* output buffer      */
+                     size_t *);      /* output buffer size */
+};
+
 /* Set a request type */
 struct flb_http_client {
     /* Upstream connection */
@@ -132,6 +197,10 @@ struct flb_http_client {
     /* Response */
     struct flb_http_client_response resp;
 
+    /* Tests */
+    int test_mode;
+    struct flb_test_http_response test_response;
+
     /* Reference to Callback context */
     void *cb_ctx;
 };
@@ -145,6 +214,13 @@ struct flb_http_client *flb_http_client(struct flb_connection *u_conn,
                                         const char *host, int port,
                                         const char *proxy, int flags);
 
+/* For fulfilling HTTP response testing (dummy client) */
+struct flb_http_client *flb_http_dummy_client(struct flb_connection *u_conn,
+                                              int method, const char *uri,
+                                              const char *body, size_t body_len,
+                                              const char *host, int port,
+                                              const char *proxy, int flags);
+
 int flb_http_add_header(struct flb_http_client *c,
                         const char *key, size_t key_len,
                         const char *val, size_t val_len);
@@ -160,6 +236,12 @@ int flb_http_set_keepalive(struct flb_http_client *c);
 int flb_http_set_content_encoding_gzip(struct flb_http_client *c);
 int flb_http_set_callback_context(struct flb_http_client *c,
                                   struct flb_callback *cb_ctx);
+int flb_http_set_response_test(struct flb_http_client *c, char *test_name,
+                               const void *data, size_t len,
+                               int status,
+                               void (*resp_callback) (void *, int, void *, size_t, void *),
+                               void *resp_callback_data);
+int flb_http_push_response(struct flb_http_client *c, const void *data, size_t len);
 
 int flb_http_get_response_data(struct flb_http_client *c, size_t bytes_consumed);
 int flb_http_do_request(struct flb_http_client *c, size_t *bytes);

include/fluent-bit/flb_lib.h

@@ -68,6 +68,9 @@ FLB_EXPORT int flb_output_set_test(flb_ctx_t *ctx, int ffd, char *test_name,
                                    void *test_ctx);
 FLB_EXPORT int flb_output_set_callback(flb_ctx_t *ctx, int ffd, char *name,
                                        void (*cb)(char *, void *, void *));
+FLB_EXPORT int flb_output_set_http_test(flb_ctx_t *ctx, int ffd, char *test_name,
+                                        void (*out_response) (void *, int, int, void *, size_t, void *),
+                                        void *out_callback_data);
 
 FLB_EXPORT int flb_filter_set(flb_ctx_t *ctx, int ffd, ...);
 FLB_EXPORT int flb_service_set(flb_ctx_t *ctx, ...);
@@ -84,6 +87,9 @@ FLB_EXPORT int flb_loop(flb_ctx_t *ctx);
 FLB_EXPORT int flb_lib_push(flb_ctx_t *ctx, int ffd, const void *data, size_t len);
 FLB_EXPORT int flb_lib_config_file(flb_ctx_t *ctx, const char *path);
 
+/* Emulate ingestions of HTTP responses for output plugins */
+FLB_EXPORT int flb_lib_response(flb_ctx_t *ctx, int ffd, int status, const void *data, size_t len);
+
 /* library context handling */
 FLB_EXPORT void flb_context_set(flb_ctx_t *ctx);
 FLB_EXPORT flb_ctx_t *flb_context_get();

include/fluent-bit/flb_output.h

@@ -167,6 +167,66 @@ struct flb_test_out_formatter {
                      size_t *);      /* output buffer size */
 };
 
+struct flb_test_out_response {
+    /*
+     * Runtime Library Mode
+     * ====================
+     * When the runtime library enable the test formatter mode, it needs to
+     * keep a reference of the context and other information:
+     *
+     * - rt_ctx : context created by flb_create()
+     *
+     * - rt_ffd : this plugin assigned 'integer' created by flb_output()
+     *
+     * - rt_step_calback: intermediary function to receive the results of
+     *                    the formatter plugin test function.
+     *
+     * - rt_data: opaque data type for rt_step_callback()
+     */
+
+    /* runtime library context */
+    void *rt_ctx;
+
+    /* runtime library: assigned plugin integer */
+    int rt_ffd;
+
+    /*
+     * "runtime step callback": this function pointer is used by Fluent Bit
+     * library mode to reference a test function that must retrieve the
+     * results of 'callback'. Consider this an intermediary function to
+     * transfer the results to the runtime test.
+     *
+     * This function is private and should not be set manually in the plugin
+     * code, it's set on src/flb_lib.c .
+     */
+    void (*rt_out_response) (void *, int, int, void *, size_t, void *);
+
+    /*
+     * opaque data type passed by the runtime library to be used on
+     * rt_step_test().
+     */
+    void *rt_data;
+
+    /* optional context for flush callback */
+    void *flush_ctx;
+
+    /*
+     * Callback
+     * =========
+     * "Formatter callback": it references the plugin function that performs
+     * data formatting (msgpack -> local data). This entry is mostly to
+     * expose the plugin local function.
+     */
+    int (*callback) (/* Fluent Bit context */
+                     struct flb_config *,
+                     void *,         /* plugin instance context */
+                     int status,     /* HTTP status code */
+                     const void *,   /* respond msgpack data */
+                     size_t,         /* respond msgpack size */
+                     void **,        /* output buffer      */
+                     size_t *);      /* output buffer size */
+};
+
 struct flb_output_plugin {
     /*
      * a 'mask' to define what kind of data the plugin can manage:
@@ -234,6 +294,7 @@ struct flb_output_plugin {
 
     /* Tests */
     struct flb_test_out_formatter test_formatter;
+    struct flb_test_out_response test_response;
 
     /* Link to global list from flb_config->outputs */
     struct mk_list _head;
@@ -384,6 +445,7 @@ struct flb_output_instance {
 
     /* Tests */
     struct flb_test_out_formatter test_formatter;
+    struct flb_test_out_response test_response;
 
     /*
      * Buffer counter: it counts the total of disk space (filesystem) used by buffers

plugins/out_es/es.c

@@ -985,6 +985,78 @@ static void cb_es_flush(struct flb_event_chunk *event_chunk,
     FLB_OUTPUT_RETURN(FLB_RETRY);
 }
 
+static int elasticsearch_response_test(struct flb_config *config,
+                                       void *plugin_context,
+                                       int status,
+                                       const void *data, size_t bytes,
+                                       void **out_data, size_t *out_size)
+{
+    int ret = 0;
+    struct flb_elasticsearch *ctx = plugin_context;
+    struct flb_connection *u_conn;
+    struct flb_http_client *c;
+    size_t b_sent;
+
+    /* Not retrieve upstream connection */
+    u_conn = NULL;
+
+    /* Compose HTTP Client request (dummy client) */
+    c = flb_http_dummy_client(u_conn, FLB_HTTP_POST, ctx->uri,
+                              NULL, 0, NULL, 0, NULL, 0);
+
+    flb_http_buffer_size(c, ctx->buffer_size);
+
+    /* Just stubbing the HTTP responses */
+    flb_http_set_response_test(c, "response", data, bytes, status, NULL, NULL);
+
+    ret = flb_http_do(c, &b_sent);
+    if (ret != 0) {
+        flb_plg_warn(ctx->ins, "http_do=%i URI=%s", ret, ctx->uri);
+        goto error;
+    }
+    if (ret != 0) {
+        flb_plg_warn(ctx->ins, "http_do=%i URI=%s", ret, ctx->uri);
+        goto error;
+    }
+    else {
+        /* The request was issued successfully, validate the 'error' field */
+        flb_plg_debug(ctx->ins, "HTTP Status=%i URI=%s", c->resp.status, ctx->uri);
+        if (c->resp.status != 200 && c->resp.status != 201) {
+            if (c->resp.payload_size > 0) {
+                flb_plg_error(ctx->ins, "HTTP status=%i URI=%s, response:\n%s\n",
+                              c->resp.status, ctx->uri, c->resp.payload);
+            }
+            else {
+                flb_plg_error(ctx->ins, "HTTP status=%i URI=%s",
+                              c->resp.status, ctx->uri);
+            }
+            goto error;
+        }
+
+        if (c->resp.payload_size > 0) {
+            /*
+             * Elasticsearch payload should be JSON, we convert it to msgpack
+             * and lookup the 'error' field.
+             */
+            ret = elasticsearch_error_check(ctx, c);
+        }
+        else {
+            goto error;
+        }
+    }
+
+    /* Cleanup */
+    flb_http_client_destroy(c);
+
+    return ret;
+
+error:
+    /* Cleanup */
+    flb_http_client_destroy(c);
+
+    return -2;
+}
+
 static int cb_es_exit(void *data, struct flb_config *config)
 {
     struct flb_elasticsearch *ctx = data;
@@ -1231,6 +1303,7 @@ struct flb_output_plugin out_es_plugin = {
 
     /* Test */
     .test_formatter.callback = elasticsearch_format,
+    .test_response.callback = elasticsearch_response_test,
 
     /* Plugin flags */
     .flags          = FLB_OUTPUT_NET | FLB_IO_OPT_TLS,