Adding Docker Image publishing workflow

.github/workflows/publish-image.yml

@@ -0,0 +1,34 @@
+name: Build and Publish Image
+
+on:
+  workflow_dispatch: # allows manual runs from the Actions tab
+
+env:
+  REGISTRY: ghcr.io
+  TOOL_NAME: 'bmxtools'
+  VERSION: '1.7.0'
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v6.0.2
+
+    - name: Log in to GHCR
+      uses: docker/login-action@v4.2.0
+      with:
+        registry: ${{ env.REGISTRY }}
+        username: ${{ github.actor }}
+        password: ${{ secrets.GITHUB_TOKEN }}
+
+    - name: Build and push
+      uses: docker/build-push-action@v7.2.0
+      with:
+        context: .
+        push: true
+        tags: ${{ env.REGISTRY }}/${{ github.repository_owner }}/${{ env.TOOL_NAME }}:latest, ${{ env.REGISTRY }}/${{ github.repository_owner }}/${{ env.TOOL_NAME }}:${{ env.VERSION }}

.gitignore

@@ -12,3 +12,4 @@ compile_commands.json
 CTestTestfile.cmake
 _deps
 out/
+.DS_Store

docs/release.md

@@ -9,10 +9,11 @@ This describes the steps for making a release.
     * Go through the PRs since the last release and add each PR and descriptive text to the `Breaking changes`, `Features`, `Bug fixes` or `Build changes` sections
 * Update the versions in the 3 main CMakeLists.txt files in the `project` blocks, where `VERSION` has the form `<major version>.<minor version>`
     * The files are [bmx CMakeLists.txt](../CMakeLists.txt), [libMXF CmakeLists.txt](../deps/libMXF/CMakeLists.txt) and [libMXFpp CmakeLists.txt](../deps/libMXFpp/CMakeLists.txt)
-* Run the [Build & Test](https://github.com/ebu/bmx/actions/workflows/build_and_test.yml) workflow in GitHub Actions using the release branch and fix any build errors and warnings
+* Update the version in the [Build and Publish Image](../.github/workflows/publish-image.yml) file, where `VERSION` has the form `<major version>.<minor version>.<patch version>`
+* Run the [Build & Test](../.github/workflows/build_and_test.yml) workflow in GitHub Actions using the release branch and fix any build errors and warnings
 * Check the [runner versions](https://docs.github.com/en/actions/using-github-hosted-runners/using-github-hosted-runners/about-github-hosted-runners) (e.g. `windows-2019` and `macos-13`) in the [release.yml](../.github/workflows/release.yml) workflow file are still available
     * Select the oldest macOS version available to help with compatibility
-* Run the [Release](https://github.com/ebu/bmx/actions/workflows/release.yml) workflow in GitHub Actions using the release branch to check it succeeds
+* Run the [Release](../.github/workflows/release.yml) workflow in GitHub Actions using the release branch to check it succeeds
     * On the release branch, create a temporary tag and then delete the tag once the workflow succeeds:
 
 ```bash
@@ -43,7 +44,7 @@ git push origin v${BMX_VERSION}
 
 ## Create the Release Packages
 
-* Run the [Release](https://github.com/ebu/bmx/actions/workflows/release.yml) workflow in GitHub Actions
+* Run the [Release](../.github/workflows/release.yml) workflow in GitHub Actions
 * Download the Artifacts and extract the individual source and binary zips for the release
 
 ## Create a GitHub Release
@@ -54,35 +55,9 @@ git push origin v${BMX_VERSION}
     * Change the CHANGELOG link
     * Update the zip filenames with the new version
     * Update the compiler versions used for the binaries
-        * These can be found in the actions output in the `Win64 binary release` and `MacOS Universal binary release` build steps in the 2 jobs of the [Release](https://github.com/ebu/bmx/actions/workflows/release.yml) workflow in GitHub Actions
+        * These can be found in the actions output in the `Win64 binary release` and `MacOS Universal binary release` build steps in the 2 jobs of the [Release](../.github/workflows/release.yml) workflow in GitHub Actions
 * Upload the source and binary zips to the release
 
 ## Create a Docker Image for the GitHub Container Registry
 
-* Acquire a Linux machine with Docker installed
-* Build the `bmxtools` image and tag using the commands below
-    * `BMX_VERSION` should be set as before; note also the additional `.0` for the patch version.
-
-```bash
-DOCKER_BUILDKIT=1 docker build --platform linux/amd64 -t bmxtools .
-docker tag bmxtools ghcr.io/ebu/bmxtools:${BMX_VERSION}.0
-docker tag bmxtools ghcr.io/ebu/bmxtools:latest
-```
-
-* In your [GitHub settings](https://github.com/settings/tokens) to create tokens
-    * Select "Generate New Token" and "Generate new token (classic)"
-        * Change "Expiration" to 7 days
-        * Select "write:packages" (which will select "read:packages" and all of "repo")
-    * Select "Generate Token"
-    * Copy the token which you'll need to pass in when logging into the GitHub Docker registry
-* Login into GHCR and push the image using the commands below
-    * Replace `<username>` with your GitHub username
-    * Pass in the token when docker login requests it
-    * `BMX_VERSION` should be set as before; note also the additional `.0` for the patch version
-
-```bash
-docker login ghcr.io --username <username>
-docker push ghcr.io/ebu/bmxtools:${BMX_VERSION}.0
-docker push ghcr.io/ebu/bmxtools:latest
-docker logout ghcr.io
-```
+* Run the [Build and Publish Image](../.github/workflows/publish-image.yml) workflow in GitHub actions on the release tag.