use kaniko to build container in ci

.editorconfig

@@ -1,9 +0,0 @@
-root = true
-
-[*]
-end_of_line = lf
-charset = utf-8
-trim_trailing_whitespace = true
-insert_final_newline = true
-indent_style = space
-indent_size = 4

.gitlab-ci.yml

@@ -1,13 +1,18 @@
 variables:
-    IMAGE_NAME: thallian/nextcloud-ldap
+  CI_REGISTRY_IMAGE: thallian/nextcloud
 
 build:
   stage: build
+  image:
+    name: gcr.io/kaniko-project/executor:debug
+    entrypoint: [""]
   script:
-        - docker login -u $DOCKER_USER -p $DOCKER_PASSWORD $DOCKER_REGISTRY
-        - docker build -t $IMAGE_NAME:$CI_COMMIT_SHA .
-        - docker build -t $IMAGE_NAME:$CI_COMMIT_REF_NAME .
-        - docker build -t $IMAGE_NAME:latest .
-        - docker push $IMAGE_NAME:$CI_COMMIT_SHA
-        - docker push $IMAGE_NAME:$CI_COMMIT_REF_NAME
-        - docker push $IMAGE_NAME:latest
+    - mkdir -p /kaniko/.docker
+    - echo "{\"auths\":{\"$CI_REGISTRY\":{\"auth\":\"$(printf "%s:%s" "$CI_REGISTRY_USER" "$CI_REGISTRY_PASSWORD" | base64 | tr -d '\n')\"}}}" > /kaniko/.docker/config.json
+    - >-
+      /kaniko/executor
+      --context "$CI_PROJECT_DIR"
+      --dockerfile "$CI_PROJECT_DIR/Dockerfile"
+      --destination "$CI_REGISTRY_IMAGE:$CI_COMMIT_SHA"
+      --destination "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_NAME"
+      --destination "$CI_REGISTRY_IMAGE:latest"