Merge branch 'add-openshift-cli-image' into 'master'

Add dockerfile and ci

See merge request !6

.gitlab-ci.yml

+stages:
+  - build
+
+.build:
+  stage: build
+  image: 
+      name: gitlab-registry.cern.ch/ci-tools/docker-image-builder
+      entrypoint: [""]
+  script:
+      - echo "{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"}}}" > /kaniko/.docker/config.json
+      - /kaniko/executor --context $CI_PROJECT_DIR --dockerfile $CI_PROJECT_DIR/Dockerfile --destination $IMAGE_DESTINATION
+      - echo "Image pushed successfully to ${IMAGE_DESTINATION}"
+
+
+#####################################################
+################### Merge Requests ##################
+
+build_mr:
+  extends: .build
+  variables:
+    IMAGE_DESTINATION: ${CI_REGISTRY_IMAGE}/openshift-cli:${CI_COMMIT_REF_SLUG}
+  rules:
+    - if:  $CI_MERGE_REQUEST_ID
+      when: manual
+      allow_failure: true
+    - when: never
+
+######################################################
+#################### Master branch ###################
+
+build_master:
+  extends: .build
+  variables:
+    IMAGE_DESTINATION: ${CI_REGISTRY_IMAGE}/openshift-cli:latest
+  rules:
+    - if: $CI_COMMIT_BRANCH == 'master'
+    - when: never

Dockerfile

+# Base image: https://github.com/Docker-Hub-frolvlad/docker-alpine-glibc
+# This image makes glibc work side by side with musl libc
+FROM frolvlad/alpine-glibc:latest
+
+LABEL maintainer="Drupal Admins <drupal-admins@cern.ch>"
+
+ARG BUILD_DEPS='tar gzip'
+ARG RUN_DEPS='curl ca-certificates gettext'
+
+RUN apk --no-cache add $BUILD_DEPS $RUN_DEPS && \
+    curl -sLo /tmp/oc.tar.gz https://mirror.openshift.com/pub/openshift-v4/x86_64/clients/ocp/stable/openshift-client-linux.tar.gz && \
+    tar xzvf /tmp/oc.tar.gz -C /usr/local/bin/ && \
+    rm -rf /tmp/oc.tar.gz && \
+    apk del $BUILD_DEPS
+
+CMD ["/usr/local/bin/oc"]