1 files changed, 79 insertions, 0 deletions
diff --git a/fluent-bit/src/flb_meta.c b/fluent-bit/src/flb_meta.c
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+++ b/fluent-bit/src/flb_meta.c
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+/* -*- 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_env.h>
+#include <fluent-bit/flb_mem.h>
+#include <fluent-bit/flb_meta.h>
+
+/*
+ * A meta is a way to extend the configuration through specific commands, e.g:
+ *
+ *   @SET a=b
+ *
+ * the meta command is prefixed with @, the command it self is 'SET' and have
+ * the parameters 'a=b'.
+ *
+ * Each command have their own handler function: meta_cmd_ABC().
+ */
+
+/* @SET command: register a key/value as a configuration variable */
+static int meta_cmd_set(struct flb_config *ctx, const char *params)
+{
+    int ret;
+    int len;
+    char *p;
+    char *key;
+    char *val;
+
+    p = strchr(params, '=');
+    if (!p) {
+        fprintf(stderr, "[meta SET] invalid parameter '%s'\n", params);
+        return -1;
+    }
+
+    len = strlen(params);
+    key = mk_string_copy_substr(params, 0, p - params);
+    if (!key) {
+        return -1;
+    }
+
+    val = mk_string_copy_substr(params, (p - params) + 1, len);
+    if (!val) {
+        flb_free(key);
+        return -1;
+    }
+
+    /* Set the variable in our local environment */
+    ret = flb_env_set(ctx->env, key, val);
+    flb_free(key);
+    flb_free(val);
+
+    return ret;
+}
+
+/* Run a specific command */
+int flb_meta_run(struct flb_config *ctx, const char *cmd, const char *params)
+{
+    if (strcasecmp(cmd, "SET") == 0) {
+        return meta_cmd_set(ctx, params);
+    }
+
+    return -1;
+}