Runner fails to upload artifacts

The runner successfully clones the project but when it gets to the artifacts upload it reports a warning:

WARNING: Uploading artifacts to coordinator... failed couldn't execute POST against http://git/ci/api/v1/builds/9611/artifacts: Post http://git/ci/api/v1/builds/9611/artifacts: dial tcp: lookup git: no such host

This happens with a gitlab-ci-multirunner 1.0.1 and GitLab Community Edition 8.4.1, both running from the latest images from Docker Hub (gitlab/gitlab-runner and sameersbn/gitlab).