run on specific shell

README.md

@@ -2,11 +2,11 @@
 
 This action targets a very specific use-case that is not currently supported by Github Workflows. This action gives you the capability to run built containers.
 
-Docker already supports running commands inside a docker image. See [jobs.<jobs_id>.container](https://help.github.com/en/actions/reference/workflow-syntax-for-github-actions#jobsjob_idcontainer). But it doesn't give you a clean way to run an image from a private repo or an image built on a previous step.
+Docker already supports running commands inside a docker image. See [jobs.<jobs_id>.container](https://help.github.com/en/actions/reference/workflow-syntax-for-github-actions#jobsjob_idcontainer). But it doesn't give you a clean way to run an image from a private repo or an image built by a previous step.
 
 ### Example Usage
 
-#### Standard use-case
+#### single-line command
 ```yaml
 - uses: addnab/docker-run-action@v1
   with:
@@ -14,7 +14,7 @@ Docker already supports running commands inside a docker image. See [jobs.<jobs_
     run: echo "hello world"
 ```
 
-#### Multiple commands
+#### multi-line commands
 ```yaml
 - uses: addnab/docker-run-action@v1
   with:
@@ -23,3 +23,28 @@ Docker already supports running commands inside a docker image. See [jobs.<jobs_
       echo "first line"
       echo "second line"
 ```
+
+#### Run on previously built container. 
+```yaml
+- uses: docker/build-push-action@v1
+  with:
+    repository: test-image
+    push: false
+- uses: addnab/docker-run-action@v1
+  with:
+    image: test-image:latest
+    run: echo "hello world"
+```
+
+
+#### use a specific shell (default: sh). 
+*Note: The shell must be installe in the container*
+```yaml
+- uses: addnab/docker-run-action@v1
+  with:
+    image: docker:latest
+    shell: bash
+    run: |
+      echo "first line"
+      echo "second line"
+```

action.yml

@@ -11,6 +11,10 @@ inputs:
   run:
     description: 'Run command in container'
     required: false
+  shell:
+    description: 'Use a specific shell'
+    required: false
+    default: sh
   registry:
     description: 'Registry'
     required: false

entrypoint.sh

@@ -6,4 +6,4 @@ fi
 
 echo "$INPUT_RUN" | sed -e 's/\\n/;/g' > semicolon_delimited_script
 
-exec docker run $INPUT_OPTIONS $INPUT_IMAGE /bin/sh -c "`cat semicolon_delimited_script`"
+exec docker run $INPUT_OPTIONS $INPUT_IMAGE /bin/$INPUT_SHELL -c "`cat semicolon_delimited_script`"