Can't access MySQL On BitBucket Cloud

[Jamie Bailey]

I'm using the `docker` service to perform a docker run command & I am also using the `mysql` service. I can seem to connect to the mysql service from within the docker container. I keep getting "connection refused" any help?

[ktomk · Accepted solution]

Hey @Jamie Bailey , welcome to the Atlassian Community.

No idea if I get you right here. So within your Pipeline Container (that is also a Docker container) you are running `docker run command-container ...` that should connect to the `mysql` service that is added to the pipeline step?

For illustration:

pipelines:
  default:
    - step:
        image: ktomk/pipelines:busybox
        script:
          - docker run command-container ...
        services:
          - mysql
          - docker

The pipeline container (ktomk/pipelines:busybox) can access the services (mysql) via localhost / 127.0.0.1.

This is either also possible for the command-container (use 127.0.0.1 for mysql as "localhost" can cause problems with Mysql) or not. I don't know.

In case it's not, it needs to find it's way through docker networking. So try with "127.0.0.1" and port "3306" first. If that is not possible the other option I know about (details) is to

If you need to communicate from a service running in docker to a service running in your build container, when starting the service provide it the following host entry using --add-host host.docker.internal:$BITBUCKET_DOCKER_HOST_INTERNAL you can then access the service using host.docker.internal:<port>.

this is not exactly your use-case but might give pointers on the networking layout. The post writes that using `--network=host` is not possible any longer, so for the `docker run` command it might still work to add the host hosts.docker.internal as outlined and then the mysql service could be available on host.docker.internal and port 3306. 

[Jamie Bailey]

Hey @ktomk 

Forgot to update, I found the solution. So while inside the container I was trying to communicate with the MariaDB/MySQL server using 127.0.0.1 & localhost and this did not work.

To access the host network on BitBucket cloud from within a docker container I used 172.17.0.1

[ktomk]

`172.17.0.1` is the default docker-ip. It may change and then it breaks.

Better would be to do the suggested internal host resolution with the Bitbucket Pipelines environment variable:

docker run --add-host host.docker.internal:"$BITBUCKET_DOCKER_HOST_INTERNAL" ...

 and then use `host.docker.internal` instead of `172.17.0.1`.

You could also `echo "$BITBUCKET_DOCKER_HOST_INTERNAL"` in a pipeline script line to see what this standard variable contains.

[Jamie Bailey]

@ktomk thank you for the help, that worked.

I did it slightly differently:

docker run --env DB_TEST_HOST=$BITBUCKET_DOCKER_HOST_INTERNAL ...

since our docker app uses this environment variable to access the MariaDB host

[ktomk]

Yes, exactly that way. Looks good to me. And great to read how it resolved.