CODEWITHSUNDEEP
dockerdocker-composegitlab-cigitlab-ci-runner
olidem
olidem

Reputation: 2121

Gitlab-CI: Bind mount failed

I am trying to configure Gitlab CI for my dockerized Symfony project.

In the test phase, I try to start my docker-compose.yml, where one service needs a bind mount. My runner does see the folder, but I cannot use it. I get as test output:

$ docker-compose -f docker-compose_deploy.yml up -d
Creating network "xxx_default" with the default driver
Creating xxx_php_1   ... 
Creating xxx_db_1    ... 

Creating xxx_php_1   ... done
Creating xxx_nginx_1 ... 

Creating xxx_db_1    ... error

ERROR: for xxx_db_1  Cannot start service db: Bind mount failed: '/backups' does not exists

To test that I included the command ls / in my before_script section. But it does show /backups, since I altered my runners' config.toml:

[[runners]]
  name = "main-runner"
  url = "https://gitlab.com/"
  token = "xyz"
  executor = "docker"
  [runners.docker]
    tls_verify = false
    image = "docker:latest"
    privileged = false
    disable_cache = false
    volumes = ["/var/run/docker.sock:/var/run/docker.sock","/volume1/docker/postgres-backup:/backups", "/cache"]
    shm_size = 0
  [runners.cache]

Here's the important part of my .gitlab-ci.yml:

before_script:
  - ls /
  - docker info
  - apk add --update py-pip && pip install docker-compose
  - docker login -u gitlab-ci-token -p $CI_BUILD_TOKEN registry.gitlab.com

build:
  stage: build
  script:
    - docker-compose -f docker-compose_deploy.yml build --pull 

test1:
  stage: test
  script:
    - docker-compose -f docker-compose_deploy.yml up -d
    - docker exec registry.gitlab.com/xxx-group/xxx_php_1 bash docker/php-fpm/initialization.sh
    - docker exec registry.gitlab.com/xxx-group/xxx_php_1 bin/console app:initialize
    - docker exec registry.gitlab.com/xxx-group/xxx_php_1 ./vendor/bin/simple-phpunit
  after_script:
    - docker-compose -f docker-compose_deploy.yml down

The docker-compose.yml is

volumes:
    pgdata:
services:
    db:
        image: postgres:9-alpine
        volumes:
            - pgdata:/var/lib/postgresql/data
            - /backups:/backups

Although the built images cannot be executed, I can inspect them: And the volume in fact is not listed there!

"Volumes": {
                "/var/lib/postgresql/data": {}
            }

Upvotes: 0

Views: 3135

Answers (2)

olidem
olidem

Reputation: 2121

To repeat Stefan von Gastel's correct answer:

When running the test (and docker-compose'ing up), in my setting, the docker commands run in the context of the docker host, i.e. the machine that executes the gitlab-runner.

So to stay in my config, a simple 

$ ln -s  /volume1/docker/postgres-backup/ /backups

solved my problem, because now the path is available. In fact, the entry in volumes in my runner's config.toml are unneccessary.

THANKS Stefan!

Upvotes: 1

Stefan van Gastel
Stefan van Gastel

Reputation: 4478

You are running docker-in-docker with a shared socket. This means that you have a Gitlab CI runner host (a.k.a HOST) and a job running in a container based on docker:latest (a.k.a JOBCONTAINER).

Your assumption is that you can mount files that exist in your JOBCONTAINER (the ones you see when you ls in your before_script) when in fact the actual container you are starting with docker-compose will run in context of the HOST since you are using its Docker daemon inside your JOBCONTAINER.

Upvotes: 4

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