Add custom abra command to run WP-CLI

Closes #2

README.md

@@ -16,6 +16,13 @@ Coöp Cloud + [Wordpress](https://wordpress.org) = 🥳
 8. `abra app YOURAPPDOMAIN run app chown www-data:www-data /var/www/html/wp-content` to fix
    file permissions (see #3)
 
+## Running WP-CLI
+
+`abra app YOURAPPDOMAIN wp 'core check-update --major'`
+
+(the WP-CLI arguments need to be quoted, because of how `abra` handles
+command-line arguments)
+
 ## Network (Multi-site)
 
 _(Only tested using subdomains)_

abra-commands.sh

@@ -0,0 +1,11 @@
+sub_wp() {
+  load_instance
+  load_instance_env
+	CONTAINER=$(docker container ls -f "Name=${STACK_NAME}_app" --format '{{ .ID }}')
+  if [ -z "$CONTAINER" ]; then
+    error "Can't find a container for ${STACK_NAME}_app"
+    exit
+  fi
+	# shellcheck disable=SC2154,SC2086
+	docker run -it --volumes-from "$CONTAINER" --network "container:$CONTAINER" wordpress:cli wp $abra__arg_
+}