output: Handle plugin aliases

Signed-off-by: Hiroshi Hatake <hiroshi@chronosphere.io>

Author: cosmo0920

src/flb_output.c

@@ -35,6 +35,7 @@
 #include <fluent-bit/flb_macros.h>
 #include <fluent-bit/flb_utils.h>
 #include <fluent-bit/flb_plugin.h>
+#include <fluent-bit/flb_plugin_alias.h>
 #include <fluent-bit/flb_plugin_proxy.h>
 #include <fluent-bit/flb_http_client_debug.h>
 #include <fluent-bit/flb_output_thread.h>
@@ -128,6 +129,7 @@ static int check_protocol(const char *prot, const char *output)
 {
     int len;
     char *p;
+    const char *alias_target;
 
     p = strstr(output, "://");
     if (p && p != output) {
@@ -137,12 +139,16 @@ static int check_protocol(const char *prot, const char *output)
         len = strlen(output);
     }
 
-    if (strlen(prot) != len) {
-        return 0;
+    /* Output plugin match */
+    if (strlen(prot) == (size_t) len &&
+        strncasecmp(prot, output, len) == 0) {
+        return 1;
     }
 
-    /* Output plugin match */
-    if (strncasecmp(prot, output, len) == 0) {
+    alias_target = flb_plugin_alias_get(FLB_PLUGIN_OUTPUT, output, len);
+    if (alias_target != NULL &&
+        strlen(alias_target) == strlen(prot) &&
+        strcasecmp(prot, alias_target) == 0) {
         return 1;
     }