feat: make ssh-private-key optional

Author: hussainweb

README.md

@@ -12,9 +12,9 @@ The project ID on platform.sh. You can find this using the CLI or the web consol
 
 A token to access platform.sh API. See instructions on [platform.sh docs](https://docs.platform.sh/development/cli/api-tokens.html).
 
-### `ssh-private-key`
+### `ssh-private-key` (optional)
 
-Apart from the token, the action also needs a private key to use to be able to push via git (the CLI uses git internally). Create a specialized key used _only_ for deployment and use Github secrets to keep your key safe.
+The platform.sh CLI generates a temporary certificate for use for deployment. However, you may still choose to provide a private key that lets you push via git. Create a specialized key used _only_ for deployment and use Github secrets to keep your key safe.
 
 ### `php-version`
 
@@ -32,5 +32,5 @@ with:
   project-id: ${{ secrets.PlatformProjectId }}
   cli-token: ${{ secrets.PlatformCliToken }}
   ssh-private-key: ${{ secrets.PlatformSshKey }}
-  php-version: 7.4
+  php-version: 8.1
 ```

action.yml

@@ -9,7 +9,7 @@ inputs:
     required: true
   ssh-private-key:
     description: 'SSH key to access the git repository on platform.sh'
-    required: true
+    required: false
   php-version:
     description: 'PHP version to setup for the CLI'
     required: true

deploy.sh

@@ -1,5 +1,11 @@
 #!/usr/bin/env bash
 
+# Set up the private key if we have one.
+if [[ -n "$SSH_PRIVATE_KEY" ]]; then
+  eval $(ssh-agent -s)
+  echo "$SSH_PRIVATE_KEY" | tr -d '\r' | ssh-add - > /dev/null
+fi
+
 # Copy known hosts into the SSH config.
 mkdir -p ~/.ssh && chmod 0700 ~/.ssh
 cat ${GITHUB_ACTION_PATH}/known_hosts >> ~/.ssh/known_hosts