{{defaultContext}} is invalid yaml

[deviantintegral]

Troubleshooting

Before submitting a bug report please read the Troubleshooting doc.

Behaviour

I'm trying the new {{defaultContext}} variable to build an image in a subdirectory with a git context: https://github.com/marketplace/actions/build-and-push-docker-images#usage

However, even a basic example throws "You have an error in your yaml syntax". I thought perhaps it needed to be a quoted string, and while that resolves the syntax error the action doesn't replace the template variable.

Steps to reproduce this issue

1. Try to build with the following workflow: https://github.com/pbkhrv/rtl_433-hass-addons/blob/73a51d224f55e2f10d4ed85fd5be7aa76902a8f5/.github/workflows/builder.yml
2. See the error in the related build log: https://github.com/pbkhrv/rtl_433-hass-addons/actions/runs/1712808308

Expected behaviour

The default string shown in the docs should work.

Configuration

• Repository URL (if public): https://github.com/pbkhrv/rtl_433-hass-addons
• Build URL (if public): https://github.com/pbkhrv/rtl_433-hass-addons/actions/runs/1712808308

name: Build rtl_433 images

on:
  push:
  pull_request:

jobs:
  build:
    name: Build rtl_433 addon
    runs-on: ubuntu-latest

    steps:

    -
      name: Set up Docker Buildx
      uses: docker/setup-buildx-action@v1

    -
      name: Build and push
      uses: docker/build-push-action@v2
      with:
        context: {{defaultContext}}:rtl_433
        platforms: linux/amd64,linux/arm64
        push: false
        tags: |
          ghcr.io/pbkhrv/rtl_433-hass-addons:latest

[crazy-max]

@deviantintegral Not released yet, you can test with uses: docker/build-push-action@master

[crazy-max]

@deviantintegral Should be ok now.

[deviantintegral]

Thanks! I think the docs may be published onto the Marketplace page before the actions are updated, as that's where I originally read about the feature. Regardless, glad this is sorted 🙌

[limbic-derek]

I'm having the exact same issue. w/ v2.8.0. It immediately fails and says I have a syntax error, like so:

You have an error in your yaml syntax on line 38

Here's my entire .yml:

name: Build Base Docker Container Image
on: [push]

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}/base
  
jobs:
  build-and-push:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
    
    steps:
      - 
       name: Docker Setup Buildx
       uses: docker/[email protected]

      - 
        name: Log in to GHCR
        uses: docker/[email protected]
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - 
        name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/[email protected]
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

      - 
        name: Build and push Docker image
        uses: docker/[email protected]
        with:
          context: {{defaultContext}}:base
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}

I'm trying to build a Dockerfile in a subdir called base.

Any guidance?

[limbic-derek]

So I tried wrapping context in quotes (like so: "{{defaultContext}}:base") and seemed to get further, it seems to be evaluating now, but still failing, now getting:

#1 [internal] load git source https://github.com/OrgName/RepoName.git#a6a9909480743cdce240ffd1824b51adf6d6a2b1:base
#1 0.143 hint: Using 'master' as the name for the initial branch. This default branch name
#1 0.143 hint: is subject to change. To configure the initial branch name to use in all
#1 0.143 hint: of your new repositories, which will suppress this warning, call:
#1 0.143 hint: 
#1 0.143 hint: 	git config --global init.defaultBranch <name>
#1 0.143 hint: 
#1 0.143 hint: Names commonly chosen instead of 'master' are 'main', 'trunk' and
#1 0.143 hint: 'development'. The just-created branch can be renamed via this command:
#1 0.143 hint: 
#1 0.143 hint: 	git branch -m <name>
#1 0.144 Initialized empty Git repository in /var/lib/buildkit/runc-overlayfs/snapshots/snapshots/1/fs/
#1 0.159 fatal: Not a valid object name a6a9909480743cdce240ffd1824b51adf6d6a2b1^{commit}
#1 1.490 fatal: could not read Username for 'https://github.com': terminal prompts disabled
#1 ERROR: failed to fetch remote https://github.com/OrgName/RepoName.git: exit status 128
------
 > [internal] load git source https://github.com/OrgName/RepoName.git#a6a9909480743cdce240ffd1824b51adf6d6a2b1:base:
#1 0.143 hint: 
#1 0.143 hint: 	git config --global init.defaultBranch <name>
#1 0.143 hint: 
#1 0.143 hint: Names commonly chosen instead of 'master' are 'main', 'trunk' and
#1 0.143 hint: 'development'. The just-created branch can be renamed via this command:
#1 0.143 hint: 
#1 0.143 hint: 	git branch -m <name>
#1 0.144 Initialized empty Git repository in /var/lib/buildkit/runc-overlayfs/snapshots/snapshots/1/fs/
#1 0.159 fatal: Not a valid object name a6a9909480743cdce240ffd1824b51adf6d6a2b1^{commit}
#1 1.490 fatal: could not read Username for 'https://github.com': terminal prompts disabled
------
error: failed to solve: failed to read dockerfile: failed to fetch remote https://github.com/OrgName/RepoName.git: exit status 128

[dimaqq]

Did I read the README correctly that:
if you use context, you must include your own checkout action?

[axisofentropy]

I also couldn't get this to work using the Git context. As other comments above have noted, it looks like:

• the docs should be updated to include "" quote marks around the {{ handlebars }}.
• buildkit does not yet support subdirectories.

This ticket should probably be re-opened.

[crazy-max]

• the docs should be updated to include "" quote marks around the {{ handlebars }}.

Good catch yes, will fix that.

buildkit does not yet support subdirectories.

Actually it is if you're using the docker-container driver with the setup-buildx-action (default). But it's true it's not yet supported for the docker driver. I will add a note about this.

if you use context, you must include your own checkout action?

context can be a local path or a git repo. For a git repo no need to add the actions/checkout step as shown in the README: https://github.com/docker/build-push-action/#git-context.