Update readme

Compatibility with configuration sources used by other tools

README.md

@@ -9,7 +9,7 @@ This is useful if you `docker push` your images to Docker Hub. It provides an ea
 
 ```yml
     - name: Docker Hub Description
-      uses: peter-evans/dockerhub-description@v2.1.0
+      uses: peter-evans/dockerhub-description@v2
       env:
         DOCKERHUB_USERNAME: ${{ secrets.DOCKERHUB_USERNAME }}
         DOCKERHUB_PASSWORD: ${{ secrets.DOCKERHUB_PASSWORD }}
@@ -18,9 +18,9 @@ This is useful if you `docker push` your images to Docker Hub. It provides an ea
 
 #### Required environment variables
 
-- `DOCKERHUB_USERNAME` - Docker Hub username. If updating a Docker Hub repository belonging to an organization, this user must have `Admin` permissions for the repository.
-- `DOCKERHUB_PASSWORD` - Docker Hub password.
-- `DOCKERHUB_REPOSITORY` - The Docker Hub repository to update in the format `<namespace>/<name>`. May also be passed as a secret if considered sensitive.
+- `DOCKERHUB_USERNAME` - Docker Hub username. If updating a Docker Hub repository belonging to an organization, this user must have `Admin` permissions for the repository. Aliases: `DOCKER_USERNAME`
+- `DOCKERHUB_PASSWORD` - Docker Hub password. Fallback to `DOCKER_PASSWORD` if set. Aliases: `DOCKER_PASSWORD`
+- `DOCKERHUB_REPOSITORY` - The Docker Hub repository to update in the format `<namespace>/<name>`. May also be passed as a secret if considered sensitive. Aliases: `DOCKER_REPOSITORY`, `GITHUB_REPOSITORY`
 
 **Note**: Docker Hub [Personal Access Tokens](https://docs.docker.com/docker-hub/access-tokens/) cannot be used as they are not supported by the API. See [here](https://github.com/docker/hub-feedback/issues/1927) and [here](https://github.com/docker/hub-feedback/issues/1914) for further details. Unfortunately, this means that enabling the new 2FA feature on Docker Hub will prevent the action from working.
 
@@ -31,7 +31,7 @@ If this is not the case, the path can be overridden with an environment variable
 
 ```yml
     - name: Docker Hub Description
-      uses: peter-evans/dockerhub-description@v2.1.0
+      uses: peter-evans/dockerhub-description@v2
       env:
         DOCKERHUB_USERNAME: ${{ secrets.DOCKERHUB_USERNAME }}
         DOCKERHUB_PASSWORD: ${{ secrets.DOCKERHUB_PASSWORD }}
@@ -58,7 +58,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: Docker Hub Description
-      uses: peter-evans/dockerhub-description@v2.1.0
+      uses: peter-evans/dockerhub-description@v2
       env:
         DOCKERHUB_USERNAME: ${{ secrets.DOCKERHUB_USERNAME }}
         DOCKERHUB_PASSWORD: ${{ secrets.DOCKERHUB_PASSWORD }}
@@ -76,7 +76,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: Docker Hub Description
-      uses: peter-evans/dockerhub-description@v2.1.0
+      uses: peter-evans/dockerhub-description@v2
       env:
         DOCKERHUB_USERNAME: ${{ secrets.DOCKERHUB_USERNAME }}
         DOCKERHUB_PASSWORD: ${{ secrets.DOCKERHUB_PASSWORD }}
@@ -94,7 +94,7 @@ docker run -v $PWD:/workspace \
   -e DOCKERHUB_PASSWORD='xxxxx' \
   -e DOCKERHUB_REPOSITORY='user1/my-docker-image' \
   -e README_FILEPATH='/workspace/README.md' \
-  peterevans/dockerhub-description:2.1.0
+  peterevans/dockerhub-description:2.2
 ```
 
 ## License

action.yml

@@ -1,9 +1,22 @@
 name: 'Docker Hub Description'
 author: 'Peter Evans'
 description: 'An action to update a Docker Hub repository description from README.md'
+# env:
+#   DOCKERHUB_USERNAME:
+#     description: Username to login to Docker Hub. Aliases: DOCKER_USERNAME
+#     required: true
+#   DOCKERHUB_PASSWORD:
+#     description: Password to login to Docker Hub. Aliases: DOCKER_PASSWORD
+#     required: true
+#   DOCKERHUB_REPOSITORY:
+#     description: Explicit Docker Hub repository name. Aliases: DOCKER_REPOSITORY, GITHUB_REPOSITORY
+#     required: true
+#   README_FILEPATH:
+#     description: Path to the repository readme.
+#     default: ./README.md
 runs:
   using: 'docker'
-  image: 'docker://peterevans/dockerhub-description:2.1.1'
+  image: 'docker://peterevans/dockerhub-description:2.2.0'
 branding:
-  icon: 'upload'  
+  icon: 'upload'
   color: 'blue'

entrypoint.sh

@@ -1,7 +1,27 @@
 #!/bin/sh -l
-set -euo pipefail
+set -eo pipefail
 IFS=$'\n\t'
 
+# Allow DOCKERHUB_* variables to be set from their DOCKER_* variant
+DOCKERHUB_USERNAME=${DOCKERHUB_USERNAME:-${DOCKER_USERNAME}}
+DOCKERHUB_PASSWORD=${DOCKERHUB_PASSWORD:-${DOCKER_PASSWORD}}
+DOCKERHUB_REPOSITORY=${DOCKERHUB_REPOSITORY:-${DOCKER_REPOSITORY}}
+
+# If the repository isn't explicitly defined, infer it from GitHub if possible
+DOCKERHUB_REPOSITORY=${DOCKERHUB_REPOSITORY:-${GITHUB_REPOSITORY}}
+
+# Validate we can authenticate
+if [ -z "$DOCKERHUB_USERNAME" ] || [ -z "$DOCKERHUB_PASSWORD" ]; then
+  echo 'Unable to authenticate with Docker Hub, set a valid $DOCKERHUB_USERNAME and $DOCKERHUB_PASSWORD'
+  exit 1
+fi
+
+# Validate we have the repository name
+if [ -z "$DOCKERHUB_REPOSITORY" ]; then
+  echo 'Unable to determine Docker Hub repository name, set with $DOCKERHUB_REPOSITORY'
+  exit 1
+fi
+
 # Set the default path to README.md
 README_FILEPATH=${README_FILEPATH:="./README.md"}