env variables validation

.env.example

@@ -2,3 +2,4 @@ GITEA_INSTANCE_BASE_URL="https://gitea.example.com"
 GITEA_ACCESS_TOKEN="access_token"
 GITEA_OWNER="owner"
 GITEA_REPOSITORY="repository"
+GITEA_PACKAGE_REGISTRY="composer"

docker-compose.yml

@@ -10,6 +10,7 @@ services:
       GITEA_ACCESS_TOKEN: ${GITEA_ACCESS_TOKEN}
       GITEA_OWNER: ${GITEA_OWNER}
       GITEA_REPOSITORY: ${GITEA_REPOSITORY}
+      GITEA_PACKAGE_REGISTRY: ${GITEA_PACKAGE_REGISTRY}
     volumes:
       - ./src:/var/src
     networks:

src/app.php

@@ -104,6 +104,30 @@ function showTerminalMessage (string $message = '', string $color = ''): void
 
 try {
 
+    if (empty(\getenv('GITEA_INSTANCE_BASE_URL'))) {
+        throw new \Exception('GITEA_INSTANCE_BASE_URL empty');
+    }
+
+    if (empty(\getenv('GITEA_ACCESS_TOKEN'))) {
+        throw new \Exception('GITEA_ACCESS_TOKEN empty');
+    }
+
+    if (empty(\getenv('GITEA_OWNER'))) {
+        throw new \Exception('GITEA_OWNER empty');
+    }
+
+    if (empty(\getenv('GITEA_REPOSITORY'))) {
+        throw new \Exception('GITEA_REPOSITORY empty');
+    }
+
+    if (empty(\getenv('GITEA_PACKAGE_REGISTRY'))) {
+        throw new \Exception('GITEA_PACKAGE_REGISTRY empty');
+    }
+
+    if (!\in_array(\getenv('GITEA_PACKAGE_REGISTRY'), ['composer'])) {
+        throw new \Exception('Package registry {' . \getenv('GITEA_PACKAGE_REGISTRY') . '} is not supported');
+    }
+
     $response = sendRequest('GET', '/api/v1/user');
     $data = responseEncode($response);