docker: fix unauthenticated pulls from gcr.io

Signed-off-by: Antonio Murdaca <[email protected]>

Author: runcom

docker/docker_client.go

@@ -265,7 +265,12 @@ func (c *dockerClient) setupRequestAuth(req *http.Request) error {
 		}
 		chs := parseAuthHeader(res.Header)
 		if res.StatusCode != http.StatusUnauthorized || chs == nil || len(chs) == 0 {
-			// try again one last time with Basic Auth (gcr.io for instance)
+			if res.StatusCode == http.StatusOK {
+				return nil // gcr.io unauthenticated pull
+			}
+			// gcr.io authenticated pull requires us to send user:pass pair in
+			// order to retrieve a token
+			// try again one last time with Basic Auth
 			testReq2 := *req
 			// Do not use the body stream, or we couldn't reuse it for the "real" call later.
 			testReq2.Body = nil