Use a python builder for handling automated fetch of tag

Signed-off-by: baalajimaestro <me@baalajimaestro.me>

.gitlab-ci.yml

@@ -2,6 +2,6 @@ docker-build:
   stage: build
   before_script:
     - echo "$DOCKER_PASSWORD" | docker login -u "$DOCKER_USERNAME" registry.baalajimaestro.me --password-stdin
+    - pip install --user -r requirements.txt
   script:
-    - docker build . -t registry.baalajimaestro.me/baalajimaestro/hugo-alpine-ext:latest
-    - docker push registry.baalajimaestro.me/baalajimaestro/hugo-alpine-ext:latest
+    - python build.py

build.py

@@ -0,0 +1,11 @@
+import subprocess
+import os
+from requests import get
+import ujson
+
+data = ujson.loads(get("https://api.github.com/repos/gohugoio/hugo/releases/latest").content)
+
+tag = data["tag_name"][1:]
+
+subprocess.run(["docker", "build", ".", "--build-arg", "HUGO_VERSION=" + tag, "-t", "registry.baalajimaestro.me/baalajimaestro/hugo-alpine-ext:latest"])
+subprocess.run(["docker", "push", "registry.baalajimaestro.me/baalajimaestro/hugo-alpine-ext:latest"])