Cannot load host Docker config from container. Remove option and rely on environment variables

README.md

@@ -39,7 +39,7 @@ docker run -d \
   centurylink/watchtower
 ```
 
-If pulling images from a private Docker registry, supply any authentication credentials with the environment variables `REPO_USER` and `REPO_PASS` or omit to leave watchtower load credentials from the default Docker config (`~/.docker/config.json`):
+If pulling images from a private Docker registry, supply any authentication credentials with the environment variables `REPO_USER` and `REPO_PASS`.
 
 ```
 docker run -d \

container/client.go

@@ -148,10 +148,6 @@ func (client dockerClient) IsContainerStale(c Container) (bool, error) {
 		
 		var opts types.ImagePullOptions // ImagePullOptions can take a RegistryAuth arg to authenticate against a private registry
 		auth, err := EncodedEnvAuth(imageName)
-		if err != nil {
-			// credentials environment vars not set, trying Docker config instead
-			auth, err = EncodedConfigAuth(imageName)
-		}
 		if err != nil {
 			log.Debug("No authentication credentials found")
 			opts = types.ImagePullOptions{}

container/trust.go

@@ -48,6 +48,7 @@ func EncodedEnvAuth(ref string) (string, error) {
 /*
  * Return an encoded auth config for the given registry
  * loaded from the docker config
+ * The docker config must be mounted on the container
  */
 func EncodedConfigAuth(ref string) (string, error) {
 	server, err := ParseServerAddress(ref)