Update .gitlab-ci.yml - build image on gitlab

.gitlab-ci.yml

 # Full project: https://gitlab.com/pages/plain-html
+variables:
+  IMAGE_TAG: $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_NAME
+  IMAGE_NAME: ${REGISTRY_SERVER}/fossgalaxy/c
+
 pages:
   stage: deploy
   script:
@@ -8,3 +12,20 @@ pages:
       - public
   rules:
     - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH
+
+container:
+  stage: publish
+  image: git.fossgalaxy.com:8042/gamedev/containers/fedora:35-podman
+  before_script:
+    - podman version
+    - buildah version
+    - echo "$CI_REGISTRY_PASSWORD" | buildah login -u "$CI_REGISTRY_USER" --password-stdin $CI_REGISTRY
+  script:
+    - cd server/
+    - export STORAGE_DRIVER=vfs
+    - buildah bud -t ${IMAGE_NAME}:${CI_COMMIT_SHA} .
+    - buildah push ${IMAGE_NAME}:${CI_COMMIT_SHA} ${CI_REGISTRY_IMAGE}:snapshot
+  after_script:
+    - podman logout "${CI_REGISTRY}"
+  rules:
+    - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH