how to redirect docker output to an artifact

[brett_mcbride]

I'm running some tests (php-cs-fixer) inside a docker container as part of a bamboo build.

I can generate output in junit format, which I want to save as a build artifact and later process with bamboo's "JUnit Parser" task.

php-cs-fixer is not able to write to file, so I want to redirect stdout to a file, either inside the container or on the bamboo host.

I can do output redirection natively with docker, like so:

$ docker run my-docker-php-image sh -c 'vendor/bin/php-cs-fixer fix --format junit > /tmp/php-cs-fixer.xml'

Whilst typing up this question, I've got something to work. Perhaps this could be cleaned up and added to the bamboo documentation?

1. create a docker task to "Run a docker container"
2. set an image (mine is php + composer + required extensions from an internal docker repo)
3. add volume for checked out code, eg ${bamboo.working.directory}/deploy => /srv/app
4. add volume for artifacts, eg ${bamboo.working.directory}/artifacts => /srv/artifacts
5. set working directory to /srv/app
6. additional arguments: "--user root" (because I had an error writing to artifacts directory, possibly due to my container running as non-root, per security recommendations?)

The docker container command is then:

sh -c '"vendor/bin/php-cs-fixer" "fix" "--dry-run" "--config=.php_cs.dist" "--using-cache=no" "--format" "junit" > /srv/artifacts/php-cs-fixer.${bamboo.buildNumber}.xml'

You need to quote the hell out of everything, and also pass the whole command through "sh -c" so that output redirection works.

Lastly, add a "JUnit Parser" task, and make it final (since the tests will not always pass)