Merge pull request #130 from whoan/issue-127

Issue 127

README.md

@@ -62,6 +62,8 @@ or
     - `on:push`: Push only if the workflow was triggered by a push.
     - `on:pull_request`: Push only if the workflow was triggered by a pull_request.
 
+- **services_regex**: Regex to filter services from compose file. Only valid when **compose_file** was provided. Default is `.+` (all services).
+
 [branch tip]: https://stackoverflow.com/questions/16080342/what-is-a-branch-tip-in-git
 
 #### Ignored if `compose_file` is set
@@ -182,6 +184,18 @@ With a compose file override:
     compose_file: docker-compose.yml > docker-compose.override.yml
 ```
 
+Filtering services by regex:
+
+```yml
+- uses: whoan/docker-build-with-cache-action@v5
+  with:
+    username: whoan
+    password: "${{ secrets.GITHUB_TOKEN }}"
+    registry: docker.pkg.github.com
+    compose_file: docker-compose.yml
+    services_regex: '(service_1|extra_service.*)' # eg: builds services called exactly "service_1" plus the ones which start with "extra_service" and may have extra chars after
+```
+
 ### Example with more options
 
 ```yml

action.yml

@@ -10,6 +10,10 @@ inputs:
   compose_file:
     description: Path to compose file
     required: false
+  services_regex:
+    description: (Optional) Regex to filter services from compose file
+    required: false
+    default: '.+'
   username:
     description: (Optional) Docker's registry user (needed to push image to repository, or to pull from private repository)
     required: false

entrypoint.sh

@@ -71,8 +71,15 @@ _gather_images() {
   local registry=$INPUT_REGISTRY
   : "${registry:=$INPUT_USERNAME}" # an empty registry defaults to DockerHub, and a username is needed to detect its images
   : "${registry:?Either registry or username (for DockerHub) is needed to build from a compose file}"
+
   images=()
-  mapfile -t images < <(_yq e ".services.[].image | select(. != null and test(\"^${registry}/\"))" "$merged_compose")
+  mapfile -t images < <(_yq e "
+    .services
+     | with_entries(select(.key | test(\"^${INPUT_SERVICES_REGEX:-.+}\$\")))
+     | .[].image
+     | select(. != null and test(\"^${registry}/\"))
+    " "$merged_compose"
+  )
 }
 
 _set_variables() {