<!--IssueSummary start--> <details> <summary> Everyone can contribute. [Help move this issue forward](https://handbook.gitlab.com/handbook/marketing/developer-relations/contributor-success/community-contributors-workflows/#contributor-links) while earning points, leveling up and collecting rewards. </summary> - [Close this issue](https://contributors.gitlab.com/manage-issue?action=close&projectId=278964&issueIid=19561) </details> <!--IssueSummary end--> ## Summary Although the usage of environment variables works (almost?) everywhere in .gitlab-ci.yml files (e.g. cache, artifacts, image, ...), variables are apparently not supported in docker service aliases. ## Steps to reproduce ```yaml # .gitlab-ci.yml stages: - test test: stage: test image: alpine:3.6 services: - name: mysql:latest alias: "$EXAMPLE_HOSTNAME" variables: EXAMPLE_HOSTNAME: "custom_mysql_hostname" MYSQL_RANDOM_ROOT_PASSWORD: "yes" script: - echo "$EXAMPLE_HOSTNAME" - cat /etc/hosts tags: - docker ``` ## Actual behavior Variables in docker services aliases are apparently not supported - instead the variable name is written to `/etc/hosts` as-is. ``` cat /etc/hosts [...] 172.17.0.2 mysql 0ed8b29901c4 runner-2e4737f8-project-169-concurrent-0-mysql-0 172.17.0.2 $EXAMPLE_HOSTNAME 0ed8b29901c4 runner-2e4737f8-project-169-concurrent-0-mysql-0 172.17.0.3 runner-2e4737f8-project-169-concurrent-0 ``` ## Expected behavior ``` cat /etc/hosts [...] 172.17.0.2 mysql 0ed8b29901c4 runner-2e4737f8-project-169-concurrent-0-mysql-0 172.17.0.2 custom_mysql_hostname 0ed8b29901c4 runner-2e4737f8-project-169-concurrent-0-mysql-0 172.17.0.3 runner-2e4737f8-project-169-concurrent-0 ``` ## Relevant logs and/or screenshots ``` Running with gitlab-ci-multi-runner 9.5.0 (413da38) on runner.example.net (2e4737f8) Using Docker executor with image alpine:3.6 ... Starting service mysql:latest ... Pulling docker image mysql:latest ... Using docker image mysql:latest ID=sha256:b4e78b89bcf31a38eab47da1b2b36235462e83beebacb7479d725367e76572cf for mysql service... Waiting for services to be up and running... Using docker image sha256:68ca2ef543ca7665db19914e2226b394f1ac85dbfadc6c3e6dc6511974914bbc for predefined container... Pulling docker image alpine:3.6 ... Using docker image alpine:3.6 ID=sha256:76da55c8019d7a47c347c0dceb7a6591144d232a7dd616242a367b8bed18ecbc for build container... Running on runner-2e4737f8-project-169-concurrent-0 via 9631295fbe60... Fetching changes... HEAD is now at 4c46c5f Demonstrates issue #2775 - Variables not used in service alias From https://gitlab.example.net/example/service-alias + 4c46c5f...5a34e5d master -> origin/master (forced update) Checking out 5a34e5d2 as master... Skipping Git submodules setup $ echo "$EXAMPLE_HOSTNAME" custom_mysql_hostname $ cat /etc/hosts 127.0.0.1 localhost ::1 localhost ip6-localhost ip6-loopback fe00::0 ip6-localnet ff00::0 ip6-mcastprefix ff02::1 ip6-allnodes ff02::2 ip6-allrouters 172.17.0.2 mysql 0ed8b29901c4 runner-2e4737f8-project-169-concurrent-0-mysql-0 172.17.0.2 $EXAMPLE_HOSTNAME 0ed8b29901c4 runner-2e4737f8-project-169-concurrent-0-mysql-0 172.17.0.3 runner-2e4737f8-project-169-concurrent-0 Job succeeded ``` ### Used GitLab Runner version ``` Running with gitlab-ci-multi-runner 9.5.0 (413da38) on runner.example.net (2e4737f8) Using Docker executor with image alpine:3.6 ... ```