api: proxy: custom: Adjust API for custom Go plugins

Signed-off-by: Hiroshi Hatake <[email protected]>

Author: cosmo0920

include/fluent-bit/flb_api.h

@@ -22,6 +22,7 @@
 
 #include <fluent-bit/flb_info.h>
 #include <fluent-bit/flb_output.h>
+#include <fluent-bit/flb_custom.h>
 
 struct flb_api {
     const char *(*output_get_property) (const char *, struct flb_output_instance *);
@@ -33,6 +34,12 @@ struct flb_api {
     void (*log_print) (int, const char*, int, const char*, ...);
     int (*input_log_check) (struct flb_input_instance *, int);
     int (*output_log_check) (struct flb_output_instance *, int);
+
+    /* To preserve ABI, we need to add these APIs after the
+     * input/output definitions. */
+    const char *(*custom_get_property) (const char *, struct flb_custom_instance *);
+    void *(*custom_get_cmt_instance) (struct flb_custom_instance *);
+    int (*custom_log_check) (struct flb_custom_instance *, int);
 };
 
 #ifdef FLB_CORE

include/fluent-bit/flb_custom.h

@@ -107,5 +107,9 @@ int flb_custom_plugin_property_check(struct flb_custom_instance *ins,
 int flb_custom_init_all(struct flb_config *config);
 void flb_custom_set_context(struct flb_custom_instance *ins, void *context);
 void flb_custom_instance_destroy(struct flb_custom_instance *ins);
+#ifdef FLB_HAVE_METRICS
+void *flb_custom_get_cmt_instance(struct flb_custom_instance *ins);
+#endif
+int flb_custom_log_check(struct flb_custom_instance *ins, int l);
 
 #endif

src/flb_api.c

@@ -24,6 +24,7 @@
 
 #include <fluent-bit/flb_input.h>
 #include <fluent-bit/flb_output.h>
+#include <fluent-bit/flb_custom.h>
 
 struct flb_api *flb_api_create()
 {
@@ -37,15 +38,18 @@ struct flb_api *flb_api_create()
 
     api->output_get_property = flb_output_get_property;
     api->input_get_property = flb_input_get_property;
+    api->custom_get_property = flb_custom_get_property;
 
 #ifdef FLB_HAVE_METRICS
     api->output_get_cmt_instance = flb_output_get_cmt_instance;
     api->input_get_cmt_instance = flb_input_get_cmt_instance;
+    api->custom_get_cmt_instance = flb_custom_get_cmt_instance;
 #endif
 
     api->log_print = flb_log_print;
     api->input_log_check = flb_input_log_check;
     api->output_log_check = flb_output_log_check;
+    api->custom_log_check = flb_custom_log_check;
 
     return api;
 }

src/flb_custom.c

@@ -27,6 +27,7 @@
 #include <fluent-bit/flb_pack.h>
 #include <fluent-bit/flb_metrics.h>
 #include <fluent-bit/flb_utils.h>
+#include <fluent-bit/flb_plugin_proxy.h>
 #include <fluent-bit/flb_upstream.h>
 #include <fluent-bit/flb_downstream.h>
 #include <chunkio/chunkio.h>
@@ -183,6 +184,24 @@ struct flb_custom_instance *flb_custom_new(struct flb_config *config,
     snprintf(instance->name, sizeof(instance->name) - 1,
              "%s.%i", plugin->name, id);
 
+    if (plugin->type == FLB_CUSTOM_PLUGIN_CORE) {
+        instance->context = NULL;
+    }
+    else {
+        struct flb_plugin_proxy_context *ctx;
+
+        ctx = flb_calloc(1, sizeof(struct flb_plugin_proxy_context));
+        if (!ctx) {
+            flb_errno();
+            flb_free(instance);
+            return NULL;
+        }
+
+        ctx->proxy = plugin->proxy;
+
+        instance->context = ctx;
+    }
+
     instance->id    = id;
     instance->alias = NULL;
     instance->p     = plugin;
@@ -352,3 +371,22 @@ void flb_custom_set_context(struct flb_custom_instance *ins, void *context)
 {
     ins->context = context;
 }
+
+#ifdef FLB_HAVE_METRICS
+void *flb_custom_get_cmt_instance(struct flb_custom_instance *ins)
+{
+    return (void *)ins->cmt;
+}
+#endif
+
+/* Check custom plugin's log level.
+ * Not for core plugins but for Golang plugins.
+ * Golang plugins do not have thread-local flb_worker_ctx information. */
+int flb_custom_log_check(struct flb_custom_instance *ins, int l)
+{
+    if (ins->log_level < l) {
+        return FLB_FALSE;
+    }
+
+    return FLB_TRUE;
+}

src/flb_plugin_proxy.c

@@ -423,7 +423,7 @@ static int flb_proxy_register_input(struct flb_plugin_proxy *proxy,
     return 0;
 }
 
-int flb_proxy_custom_cb_init(struct flb_custom_instance *ins,
+int flb_proxy_custom_cb_init(struct flb_custom_instance *c_ins,
                              struct flb_config *config, void *data);
 
 static int flb_proxy_custom_cb_exit(void *custom_context, 
@@ -660,23 +660,32 @@ int flb_plugin_proxy_set(struct flb_plugin_proxy_def *def, int type,
     return 0;
 }
 
-int flb_proxy_custom_cb_init(struct flb_custom_instance *ins,
+int flb_proxy_custom_cb_init(struct flb_custom_instance *c_ins,
                              struct flb_config *config, void *data)
 {
     int ret = -1;
     struct flb_plugin_proxy_context *pc;
     struct flb_plugin_proxy *proxy;
 
-    pc = (struct flb_plugin_proxy_context *)(ins->context);
+    pc = (struct flb_plugin_proxy_context *)(c_ins->context);
     proxy = pc->proxy;
 
+    /* Before to initialize, set the instance reference */
+    pc->proxy->instance = c_ins;
+
     if (proxy->def->proxy == FLB_PROXY_GOLANG) {
 #ifdef FLB_HAVE_PROXY_GO
         ret = proxy_go_custom_init(proxy);
 #endif
     }
 
-    return ret;
+    if (ret == -1) {
+        flb_error("[custom] could not initialize '%s' plugin",
+                  c_ins->p->name);
+        return -1;
+    }
+
+    return 0;
 }
 
 int flb_proxy_custom_cb_exit(void *custom_context, 

src/proxy/go/go.c

@@ -42,7 +42,7 @@
  *
  *      - name: shortname of the plugin.
  *      - description: plugin description.
- *      - type: input, output, filter, processor, custom.
+ *      - type: input, output, filter, custom, whatever.
  *      - proxy: type of proxy e.g. GOLANG
  *      - flags: optional flags, not used by Go plugins at the moment.
  *