[CI] Fix docker pull from internal registry

[kuisathaverat]

if we make a docker pull we can pull the image but the command cd x-pack/metricbeat; mage update build test cannot pull the image. We have to find why and fix it.
When we fix the issue we can remove the workaround from the Jenkinsfile.

related to #17620

[kuisathaverat]

I think github.com/elastic/beats/v7/libbeat/tests/compose ignores the Docker credentials.

[kuisathaverat]

I think https://golang.org/pkg/os/exec ignores de environment variables defined on the parent environment, because of that HOME is incorrect and the Docker credentials are not defined.

[andrewkroh]

I had to do a little hunting to understand why the docker login was required. IIUC the integration tests for Metricbeat that run when TEST_TAGS=oracle require a non-public image.

The integrations tests that are using github.com/elastic/beats/v7/libbeat/tests/compose are being run inside of this container:

beats/x-pack/metricbeat/docker-compose.yml

Lines 4 to 14 in 6160e20

	beat:
	build: ../../metricbeat
	environment:
	- BEAT_STRICT_PERMS=false
	- TEST_ENVIRONMENT=false
	working_dir: /go/src/github.com/elastic/beats/x-pack/metricbeat
	volumes:
	- ${PWD}/../..:/go/src/github.com/elastic/beats/
	- /var/run/docker.sock:/var/run/docker.sock
	network_mode: host
	command: make

docker login persists state to $HOME/.docker/config.json. So if Metricbeat needs those credentials then you could add it like:

$ git diff .
diff --git a/x-pack/metricbeat/docker-compose.yml b/x-pack/metricbeat/docker-compose.yml
index c89b55860..83ac016ff 100644
--- a/x-pack/metricbeat/docker-compose.yml
+++ b/x-pack/metricbeat/docker-compose.yml
@@ -10,6 +10,7 @@ services:
     volumes:
       - ${PWD}/../..:/go/src/github.com/elastic/beats/
       - /var/run/docker.sock:/var/run/docker.sock
+      - ${HOME}/.docker:/root/.docker:ro
     network_mode: host
     command: make

And since it's only x-pack/metricbeat's integration tests requiring this maybe it's best to only do the dockerLogin from that particular stage?

[kuisathaverat]

Couchbase needs to login too and more will come sure.

[kuisathaverat]

I have to tested it but this add the credentials to the metricbeat Docker container, Do the metricbeat Docker container build the Oracle image for the tests?

[andrewkroh]

Yes, I believe docker-compose starts this service on demand when the test asks for it. And the test is running inside of a container.