libmason

Libmason 🐳 👷

Libmason an helper library to build client-driven docker container image builder. It is still very experimental.

The goal of libmason is to provide few helpers to ease the pain of creating client-side docker image builder for those who find the Dockerfile and docker build a little bit too limited.

It uses engine-api and is pretty tied to it (some structs of engine-api are popping up for now).

Helpers & Builders

As previously said, libmason provides some helpers to create client-side builders, from the most low-level (almost API level) to some higher level (with concept of Steps, commit/non-commit step, etc…). Those helpers are designed to be composable.

Base

The base Helper is located in the main package (libmason). It's a low level interface (and implementation) of commands that might be needed for a builder (get the image, create a container, commit a container to an image, etc.).

import (
    "github.com/vdemeester/libmason"
    "github.com/docker/engine-api/types"
    "github.com/docker/engine-api/types/container"
)
// […]

ctx := context.Background()

helper := libmason.Newhelper(client)
// […]

image, err := helper.GetImage(ctx, "busybox", types.ImagePullOptions{})
// […]

resp, err := helper.ContainerCreate(ctx, types.ContainerCreateConfig{
    Config: &container.Config{
        Image: image.ID,
    }
}
// […]

imageID, err := helper.ContainerCommit(ctx, resp.ID, types.ContainerCommitOptions{})
// […]

Builder

The builder package currently holds a StepBuilder which consists of a composition of Step executed in order.

import (
    "github.com/vdemeester/libmason/builder"
)
// […]

steps := []Step{
    &MyStep{},
    // A step with that needs to create a container
    builder.WithDefaultCreate(&AnotherStep{}),
    // A step that will commit the container
    builder.WithCommit(&AThirdStep{}),
    // Or remove the container
    builder.WithRemove(&AFourthStep{}),
    // Or all of them ?
    builder.WithCreate(build.WithCommitAndRemove(&MyStep{})),
}

builder := builder.WithSteps(builder.DefaultBuilder(client))
image, err := builder.Run()
// […]

See the godoc on how to create steps.