Merge branch '2-build-and-publish-automatically-on-tags' into 'master'

feat: build and publish the docker image on tags

Closes #2

See merge request !6

.gitlab-ci.yml

+image: docker:19.03.6
+
+stages:
+  - build
+
+variables:
+  DOCKER_DRIVER: overlay2
+  DOCKER_TLS_CERTDIR: ""
+
+services:
+  - name: docker:19.03.6-dind
+    command: ["--mtu=1458"]
+
+build and publish the image:
+  stage: build
+  before_script:
+    - docker info
+    - echo " --------------------------------- "
+  script:
+    # Login into gitlab registry. If that fails, the script should exit
+    - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN $CI_REGISTRY
+
+    # Get the previous version, so that we could reuse the cache
+    - 'docker pull $CI_REGISTRY_IMAGE:latest || true'
+
+    # Build the new version, assign new tag and `latest` tag
+    - docker build --cache-from $CI_REGISTRY_IMAGE:latest .
+    - docker build -t $CI_REGISTRY_IMAGE:$(CI_COMMIT_TAG) .
+
+    # Push the newly built version to the registry
+    - docker push $CI_REGISTRY_IMAGE
+  tags:
+    - privileged
+  rules:
+    - if: $CI_COMMIT_TAG

Gemfile

@@ -6,8 +6,7 @@ gem "minima", "~> 2.5"
 gem 'jekyll-theme-lcsb-default', '~> 0.3.3', :git => "https://git-r3lab.uni.lu/core-services/jekyll-theme-lcsb-default.git", :tag => "0.3.3"
 
 group :jekyll_plugins do
- gem "jekyll-paginate-v2", "~> 3",
-     :git => "https://github.com/sverrirs/jekyll-paginate-v2.git"
+ gem "jekyll-paginate-v2", "~> 3"
  gem "jekyll-feed", "~> 0.6"
 end