filter_nest: Add config property suppress_warnings to skip lift errors

In case of lift, if there's no valid/matching key found and the
content cannot be lifted, the filter  will throw an error. However, there
can be scenarios, where it is intended that sometimes the lift filter does
not find a match (like two different kinds of logs with the same tag).
Then these warnings should be disableable by the user. This commit adds an
option to suppress these kind of warnings.

Signed-off-by: Richard Treu <[email protected]>

plugins/filter_nest/nest.c

@@ -146,6 +146,9 @@ static int configure(struct filter_nest_ctx *ctx,
             ctx->prefix = flb_strdup(kv->val);
             ctx->prefix_len = flb_sds_len(kv->val);
             ctx->remove_prefix = true;
+        }
+        else if (strcasecmp(kv->key, "suppress_warnings") == 0) {
+            continue;
         } else {
             flb_plg_error(ctx->ins, "Invalid configuration key '%s'", kv->key);
             return -1;
@@ -385,9 +388,11 @@ static inline bool is_kv_to_lift(msgpack_object_kv * kv,
         }
         memcpy(tmp, key, klen);
         tmp[klen] = '\0';
-        flb_plg_warn(ctx->ins, "Value of key '%s' is not a map. "
-                     "Will not attempt to lift from here",
-                     tmp);
+        if (ctx->suppress_warnings == false) {
+            flb_plg_warn(ctx->ins, "Value of key '%s' is not a map. "
+                          "Will not attempt to lift from here",
+                          tmp);
+        }
         flb_free(tmp);
         return false;
     }
@@ -757,6 +762,11 @@ static struct flb_config_map config_map[] = {
     0, FLB_FALSE, 0,
     "Remove prefix from affected keys if it matches this string"
    },
+   {
+    FLB_CONFIG_MAP_BOOL, "suppress_warnings", "false",
+    0, FLB_TRUE, offsetof(struct filter_nest_ctx, suppress_warnings),
+    "Suppress warnings about non-matching keys"
+   },
    {0}
 };
 

plugins/filter_nest/nest.h

@@ -35,6 +35,7 @@ struct filter_nest_ctx
     int key_len;
     char *prefix;
     int prefix_len;
+    bool suppress_warnings;
     // nest
     struct mk_list wildcards;
     int wildcards_cnt;