For more frequently asked questions (FAQ) see GitHub and Stackoverflow


Debug toolbar visible with YII_DEBUG=0

Solution Set YII_ENV=dev which is the variable responsible for the debug toolbar.

AssetManager warning

PHP Warning – yii\base\ErrorException

Cannot use a scalar value as an array
1. in /app/vendor/yiisoft/yii2/web/AssetManager.php

:warning: Fix Check your application for missing asset files or configuration.


Slow or hanging updates

If you're experiencing slow updates, check what's going on in detail with

composer -vvv update

Can't use @dev or dev-master packages

You need to use, see also

config settings

"asset-pattern-skip-version": "(-build|-patch)"


Port is already allocated

ERROR: Cannot start container 88b754d7e46aca58961ef0a049216f0e7331e35ba905d84fab01016a4797a779: failed to create endpoint appdev_mariadb_1 on network bridge: Bind for failed: port is already allocated

Remove or change your port mapping.

Can't push to private registry

See also issue on GitHub

Solution Add the nameserver on your boot2docker vm

echo "nameserver" > /etc/resolv.conf && sudo /etc/init.d/docker restart

VM harddisk out of space


docker run -v /var/run/docker.sock:/var/run/docker.sock -v /var/lib/docker:/var/lib/docker --rm martin/docker-cleanup-volumes

Service 'php' failed to build

Pulling repository
ERROR: Service 'php' failed to build: Network timed out while trying to connect to You may want to check your internet connection or if you are behind a proxy.
make: *** [build] Error 1

MySQL connection takes more than 5 seconds

Check your DNS settings, restart VM with docker-machine.

Can not connect to hosts on private networks

May be caused by overlapping subnets, as workaround is to remove networks with docker network ls -q | xargs docker rnetwork rm.

Cleanup volumes


Cleanup images and containers

docker run \
	-it \
	-v /var/run/docker.sock:/var/run/docker.sock \
	yelp/docker-custodian \
		dcgc --max-image-age=30d --max-container-age=1d --dry-run

Registry Login

Interactive login

docker login

Login docker CLI

docker login --username=${YOUR_USER} --password=${YOUR_PASS}

Note! Check if Docker saves the credentials locally in ~/.docker

Gitlab CI Server


In case of weird errors you have the following workaround options, which you should try from to bottom:

  • Retry
  • Run a clean-script from time to time.
  • Use a different COMPOSE_PROJECT_NAME name for the CI jobs.
  • Clean project build folder via NAS
  • Clean project build folder via SSH to runner host and docker exec -it runner-x bash
  • Restart Docker daemon (sudo service docker restart and docker start runner-a runner-b ...
  • Move the project to another runner
  • Create a new runner
  • Reboot the runner-host (runners should have restart=always policy)
  • Recreate the runner-host (last resort)


$ bash build/scripts/
Username: EOF

Build variables like REGISTRY_USER not set.

SSH protocol error

> fatal: protocol error: bad line length character: No s

Check SSH key and correct spelling.

Todo: How to allow artifacts? ... cp to tmp and cp from tmp (EXPERIMENTAL!)


Running docker-compose on Windows can be painfully, because at least up to version 1.8.0-RC2 there's no interactive mode for commands like exec or run which renders them pretty unusable for development.

As a workaround you can use docker exec -it appname_php_1 bash to start a bash in a PHP container.

We recommend to run Docker CLI tools from a Linux VM on Windows.

Help us to improve the documentation, fork this page.