mirror of
https://gitea.com/docker/build-push-action.git
synced 2024-11-23 09:59:38 +01:00
95 lines
2.1 KiB
Markdown
95 lines
2.1 KiB
Markdown
# Named contexts
|
|
|
|
You can define [additional build contexts](https://docs.docker.com/engine/reference/commandline/buildx_build/#build-context)
|
|
that can be accessed in your Dockerfile with `FROM name` or `--from=name`. When
|
|
Dockerfile defines a stage with the same name it is overwritten.
|
|
|
|
This can be useful with GitHub Actions to reuse results from other builds or
|
|
pin an image to a spcific tag in your workflow.
|
|
|
|
## Pin image to a specific tag
|
|
|
|
Replace `alpine:latest` with a pinned one:
|
|
|
|
```dockerfile
|
|
# syntax=docker/dockerfile:1
|
|
FROM alpine
|
|
RUN echo "Hello World"
|
|
```
|
|
|
|
```yaml
|
|
name: ci
|
|
|
|
on:
|
|
push:
|
|
branches:
|
|
- 'main'
|
|
|
|
jobs:
|
|
docker:
|
|
runs-on: ubuntu-latest
|
|
steps:
|
|
-
|
|
name: Checkout
|
|
uses: actions/checkout@v3
|
|
-
|
|
name: Set up Docker Buildx
|
|
uses: docker/setup-buildx-action@v2
|
|
-
|
|
name: Build
|
|
uses: docker/build-push-action@v3
|
|
with:
|
|
context: .
|
|
build-contexts: |
|
|
alpine=docker-image://alpine:3.16
|
|
tags: myimage:latest
|
|
```
|
|
|
|
## Usage of the built image in other build steps
|
|
|
|
By default, the [`setup-buildx` action](https://github.com/docker/setup-buildx-action#about)
|
|
uses `docker-container` as a build driver, so built Docker images are not
|
|
available in the builder container.
|
|
|
|
With named contexts you can reuse the built image:
|
|
|
|
```dockerfile
|
|
# syntax=docker/dockerfile:1
|
|
FROM alpine
|
|
RUN echo "Hello World"
|
|
```
|
|
|
|
```yaml
|
|
name: ci
|
|
|
|
on:
|
|
push:
|
|
branches:
|
|
- 'main'
|
|
|
|
jobs:
|
|
docker:
|
|
runs-on: ubuntu-latest
|
|
steps:
|
|
-
|
|
name: Checkout
|
|
uses: actions/checkout@v3
|
|
-
|
|
name: Set up Docker Buildx
|
|
uses: docker/setup-buildx-action@v2
|
|
-
|
|
name: Build base image
|
|
uses: docker/build-push-action@v3
|
|
with:
|
|
context: base
|
|
load: true
|
|
tags: my-base-image:latest
|
|
-
|
|
name: Build
|
|
uses: docker/build-push-action@v3
|
|
with:
|
|
context: .
|
|
build-contexts: |
|
|
alpine=docker-image://my-base-image:latest
|
|
tags: myimage:latest
|
|
```
|