add env compatibility with DOCKER_ prefixes

README.md

@@ -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_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.
+- `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.
+- `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.
 

action.yml

@@ -7,3 +7,13 @@ runs:
 branding:
   icon: 'upload'
   color: 'blue'
+inputs:
+  dockerhubUsername:
+    description: Username to login to Docker Hub. Aliases: DOCKER_USERNAME
+    required: false
+  dockerhubPassword:
+    description: Password to login to Docker Hub. Aliases: DOCKER_PASSWORD
+    required: false
+  dockerhubRepository:
+    description: Explicit Docker Hub repository name. Aliases: DOCKER_REPOSITORY, GITHUB_REPOSITORY
+    required: false

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"}