Failing to pull image from private registry

Summary

Getting the following error when the runner attempts to pull an image from a private registry (I have masked out the registry endpoint and image/org names):

Running with gitlab-ci-multi-runner 1.9.1 (b23d3d4)
WARNING: environment is not supported by selected executor and shell
Using Docker executor with image <registry>/<org>/<image>:<tag> ...
Pulling docker image <registry>/<org>/<image>:<tag> ...
ERROR: Build failed: API error (404): repository <registry>/<org>/<image> not found: does not exist or no pull access

I have set the DOCKER_AUTH_CONFIG variable per the docs here and validated that that same auth token has access to push/pull from that repository in the registry.

Steps to reproduce

  1. Configure DOCKER_AUTH_CONFIG variable with auth info (I have masked the actual registry, auth, and identitytoken values):
{
  "auths": {
    "<registry>": {
			"auth": "<value>",
			"identitytoken": "<value>"
		}
	}
}

  1. Set image property in gitlab-ci.yml to use image in private registry image: <registry>/<org>/<image>:<tag>

  2. Run pipeline

Actual behavior

The image pull fails

Expected behavior

The image is successfully pulled from the private registry

Environment description

Docker v1.13.0 GitLab CE 8.15.2 (790035f)

Used GitLab Runner version

docker exec -it gitlab-runner /bin/sh

# gitlab-runner --version
Version:      1.9.1
Git revision: b23d3d4
Git branch:
GO version:   go1.7.4
Built:        Tue, 27 Dec 2016 15:30:25 +0000
OS/Arch:      linux/amd64