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Docker

Docker work runs on an agent's machine. Install and Build are actions; containers, networks and volumes are owned resource records.

Install and build​

report, err := activity.Activity(ctx, agent, dockerlib.Install())

build, err := activity.Activity(ctx, agent, dockerlib.Build(dockerlib.BuildSpec{
    Context:   machine.Workspace() + "/src/app",
    Tags:      []string{"registry.example/app:sha"},
    Push:      true,
    Target:    "release",
    BuildArgs: map[string]string{"VERSION": version},
    CacheFrom: []string{"type=registry,ref=registry.example/app:cache"},
    CacheTo:   []string{"type=registry,ref=registry.example/app:cache,mode=max"},
}))

Install converges an existing engine or installs one with the machine's package manager, then publishes capability docker. Build uses the machine's Buildx/BuildKit and returns the digest and tags. Paths must be valid on the machine; machine.Workspace() is the shared same-path location.

Container​

web := dockerlib.Container(ctx, agent, dockerlib.Spec{
    Name: "web",
    Config: &container.Config{Image: "nginx:alpine"},
    Host: &container.HostConfig{
        RestartPolicy: container.RestartPolicy{Name: container.RestartPolicyAlways},
    },
    Scrape: "http://localhost:9187/metrics",
}, pipeline.WithLabels(map[string]string{"role": "frontend"}))

id := web.Ready(ctx).Id

Config and Host are Docker's native Go types. Declaration is idempotent by name: an absent container is created and started; a stopped one is started. Scrape asks the agent to pull a Prometheus endpoint and attribute samples to the container record.

Network and volume​

net := dockerlib.Network(ctx, agent, dockerlib.NetworkSpec{
    Name: "private",
    Options: network.CreateOptions{Driver: "bridge"},
})

data := dockerlib.Volume(ctx, agent, volume.CreateOptions{Name: "db-data"})

Both use Docker's native option structs and converge by name. Finalize removes the Docker object; a volume's data therefore dies with its owner. Transfer a resource to the stand when it must survive its run.

When the agent is owned by the run, Docker resources become its children. On an attached agent they stay owned by the run: foreign resources cannot be made responsible for your declarations.

Local tests​

See Local tests for fixtures, dependency adapters and pipeline assertions.