Merge pull request #15699 from yashykt/noproxyarg

Add channel arg to enable/disable http proxy

include/grpc/impl/codegen/grpc_types.h

@@ -336,6 +336,8 @@ typedef struct {
 /** If non-zero, client authority filter is disabled for the channel */
 #define GRPC_ARG_DISABLE_CLIENT_AUTHORITY_FILTER \
   "grpc.disable_client_authority_filter"
+/** If set to zero, disables use of http proxies. Enabled by default. */
+#define GRPC_ARG_ENABLE_HTTP_PROXY "grpc.enable_http_proxy"
 /** \} */
 
 /** Result of a grpc call. If the caller satisfies the prerequisites of a

src/core/ext/filters/client_channel/http_proxy.cc

@@ -83,11 +83,24 @@ done:
   return proxy_name;
 }
 
+/**
+ * Checks the value of GRPC_ARG_ENABLE_HTTP_PROXY to determine if http_proxy
+ * should be used.
+ */
+bool http_proxy_enabled(const grpc_channel_args* args) {
+  const grpc_arg* arg =
+      grpc_channel_args_find(args, GRPC_ARG_ENABLE_HTTP_PROXY);
+  return grpc_channel_arg_get_bool(arg, true);
+}
+
 static bool proxy_mapper_map_name(grpc_proxy_mapper* mapper,
                                   const char* server_uri,
                                   const grpc_channel_args* args,
                                   char** name_to_resolve,
                                   grpc_channel_args** new_args) {
+  if (!http_proxy_enabled(args)) {
+    return false;
+  }
   char* user_cred = nullptr;
   *name_to_resolve = get_http_proxy_server(&user_cred);
   if (*name_to_resolve == nullptr) return false;