- 
-
- **Very experimental proof of concept.**
-
- Blubber is a highly opinionated abstraction for container build configurations
- and a command-line compiler which currently supports outputting multi-stage
- Dockerfiles. It aims to provide a handful of declarative constructs that
- accomplish build configuration in a more secure and determinate way than
- running ad-hoc commands.
-
- ## Example configuration
-
- ```yaml
- version: v4
- base: debian:jessie
- apt:
- packages: [libjpeg, libyaml]
- lives:
- in: /srv/service
- runs:
- environment:
- FOO: bar
- BAR: baz
-
- variants:
- build:
- apt:
- packages: [libjpeg-dev, libyaml-dev]
- node:
- requirements: [package.json, package-lock.json]
- copies: [local]
-
- development:
- includes: [build]
-
- test:
- includes: [build]
- apt:
- packages: [chromium]
- entrypoint: [npm, test]
-
- prep:
- includes: [build]
- node:
- env: production
-
- production:
- base: debian:jessie-slim
- node:
- env: production
- copies: [prep]
- entrypoint: [node, server.js]
- ```
-
- ## Variants
-
- Blubber supports a concept of composeable configuration variants for defining
- slightly different container images while still maintaining a sufficient
- degree of parity between them. For example, images for development and testing
- may require some development and debugging packages which you wouldn't want in
- production lest they contain vulnerabilities and somehow end up linked or
- included in the application runtime.
-
- Properties declared at the top level are shared among all variants unless
- redefined, and one variant can include the properties of others. Some
- properties, like `apt:packages` are combined when inherited or included.
-
- In the example configuration, the `test` variant when expanded effectively
- becomes:
-
- ```yaml
- version: v4
- base: debian:jessie
- apt:
- packages: [libjpeg, libyaml, libjpeg-dev, libyaml-dev, chromium]
- node:
- dependencies: true
- runs:
- in: /srv/service
- as: runuser
- uid: 666
- gid: 666
- entrypoint: [npm, test]
- ```
-
- ## Artifacts
-
- When trying to ensure optimally sized Docker images for production, there's a
- common pattern that has emerged which is essentially to use one image for
- building an application and copying the resulting build artifacts to another
- much more optimized image, using the latter for production.
-
- The Docker community has responded to this need by implementing
- [multi-stage builds](https://github.com/moby/moby/pull/32063) and Blubber
- makes use of this with its `copies` configuration property.
-
- In the example configuration, the `production` variant declares artifacts to
- be copied over from the result of building the `prep` image.
-
- ## Usage
-
- Running the `blubber` command will be produce `Dockerfile` output for the
- given variant.
-
- blubber config.yaml variant
-
- You can see the result of the example configuration by cloning this repo and
- running (assuming you have go):
-
- make
- ./bin/blubber blubber blubber.example.yaml development
- ./bin/blubber blubber blubber.example.yaml test
- ./bin/blubber blubber blubber.example.yaml production
-
- ## Contribution
-
- If you'd like to make code contributions to Blubber, see
- [CONTRIBUTING.md](CONTRIBUTING.md).
|
