feat: complete dockerization (optional)

features/docker-deployment.feature

@@ -0,0 +1,45 @@
+Feature: Docker deployment
+  RenewCMS can run in a container built from the repository. The container
+  reuses the existing configuration contract in cmd/server/main.go
+  (requiredEnvVars, envDefaults); no new variables are introduced.
+
+  Background:
+    Given the image is built with the default build, without the nofrontend tag
+    And the container runs the binary directly as PID 1 under a non-root user
+    And the environment sets DB_FILE and UPLOAD_DIR to paths on a named volume
+    And the required variables PUBLIC_URL, JWT_SECRET, SMTP_LOGIN, SMTP_SENDER, SMTP_PASSWORD, SMTP_HOST and SMTP_PORT come from an env file at runtime
+
+  Scenario: Healthy start
+    When the container starts with every required variable set
+    Then it logs "RenewCMS <version> (production) listening on :8080"
+    And GET /healthz on the published port returns 200 with the body "ok"
+
+  Scenario: Frontend and API are both served
+    When the container is running
+    Then GET / returns 200 with the SPA index.html
+    And GET /v1/auth/registration returns 200 with a JSON body
+
+  Scenario Outline: A missing required variable stops the container
+    When the container starts without <variable>
+    Then the process exits with a non-zero status
+    And the log contains "Environment variable <variable> is not set"
+
+    Examples:
+      | variable      |
+      | PUBLIC_URL    |
+      | JWT_SECRET    |
+      | SMTP_LOGIN    |
+      | SMTP_SENDER   |
+      | SMTP_PASSWORD |
+      | SMTP_HOST     |
+      | SMTP_PORT     |
+
+  Scenario: Data survives container recreation
+    Given an account was registered while the container was running
+    When the container is removed and recreated on the same named volume
+    Then the same account can log in
+
+  Scenario: Graceful shutdown on SIGTERM
+    When the container receives SIGTERM
+    Then the log contains "shutting down..."
+    And the container exits with status 0 within 10 seconds