Add support for custom ssh port when using ssh_domain option

Author: alexdenvir

action.yml

@@ -61,6 +61,10 @@ inputs:
     description: The domain to gather SSH public keys for (automatic for github.com, gitlab.com, bitbucket.org)
     required: false
 
+  ssh_port:
+    description: Custom port to use in conjunction with ssh_domain
+    required: false
+
   working_dir:
     description: Use the given directory as working directory
     required: false
@@ -92,6 +96,7 @@ runs:
         ACTION_SSH_KEY: ${{ inputs.ssh_key }}
         ACTION_SSH_KEY_PUB: ${{ inputs.ssh_key_pub }}
         ACTION_SSH_DOMAIN: ${{ inputs.ssh_domain }}
+        ACTION_SSH_PORT: ${{ inputs.ssh_port }}
         ACTION_WORKING_DIR: ${{ inputs.working_dir }}
         ACTION_MEMORY_LIMIT: ${{ inputs.memory_limit }}
       id: composer_run

composer-action.bash

@@ -33,7 +33,12 @@ then
 
 	if [ -n "$ACTION_SSH_DOMAIN" ]
 	then
-		ssh-keyscan -t rsa "$ACTION_SSH_DOMAIN" >> ~/.ssh/known_hosts
+		if [ -n "$ACTION_SSH_PORT" ]
+		then
+			ssh-keyscan -t rsa -p $ACTION_SSH_PORT "$ACTION_SSH_DOMAIN" >> ~/.ssh/known_hosts
+                else
+			ssh-keyscan -t rsa "$ACTION_SSH_DOMAIN" >> ~/.ssh/known_hosts
+		fi
 	fi
 
 	echo "$ACTION_SSH_KEY" > ~/.ssh/action_rsa