specifying target docker daemon for jibDockerBuild

[gintautassulskus]

Section Build to Docker daemon provides an example on how to build and push a docker image to minikube docker daemon:

eval $(minikube docker-env)
gradle jibDockerBuild

Is there a gradle-native way to configure target docker daemon for the jib plugin?
I have multiple minikube instances running at the same time and must use minikube --profile option to retrieve specific minikube's docker-envs.

[coollog]

Hmm, there isn't a way in Jib to configure the target Docker daemon. jibDockerBuild just uses the docker on your PATH, which reads the environment variables that define the target Docker daemon. Configuring the environment to run docker with is a feature we should probably support.

The options are to

• Provide configuration for dockerHost, dockerTlsVerify, dockerCertPath, and dockerApiVersion
• Provide configuration for environment variables in general for docker invocations

[gintautassulskus]

At first glance, the variable approach seems a bit neater, but the support for environment variable ingestion is more future-proof and flexible.
Whatever the decision, the end solution should integrate well with the minikube plugin.

I have opened an issue which I believe is somewhat relevant to this one.

[coollog]

Since it might be confusing to have environment on the jib extension (which configures the entire build), we may have the jibDockerBuild task configurable with environment variables, so it would look something like:

tasks.jibDockerBuild.environment 'NAME', 'VALUE'

Similarly, for Maven, only the jib:dockerBuild goal will be configurable with dockerBuildEnvironment.

[gintautassulskus]

In response to #1173 (comment)

We have a number of multi-project gradle builds that require separate development enviromments. Hence the need for Minikube profiles.

If the following PR gets accepted (GoogleContainerTools/minikube-build-tools-for-java#146), then the push of docker images would look something like:

    jibDockerBuild {
        doLast {
            dockerExecutable = "/usr/local/bin/docker"
            dockerEnvironment = minikube.getDockerEnv(projectID)
        }
    }

Where minikube.getDockerEnv(profileID) retrieves docker ENV configuration from the specified minikube instance and configures the jibDockerBuild task to deploy the image to the very same minikube instance.

This way developers can work on two projects at a time with fully isolated enviroments. For smaller projects, minikube with 2-4GB of ram is more than enough. Considering modern hardware it is feasible to comfortably run at least two such instances at the same time.

[coollog]

Version 0.10.0 has been released with this fixed!

[chanseokoh]

Not available for Maven, let's leave this open. I think it's better than creating another issue.