Update .gitlab-ci.yml, Dockerfile, requirements.txt files

.gitlab-ci.yml

+stages:
+  - build_image
+
+build_image:
+  stage: build_image
+  before_script:
+    - export REG_NAME=registry.getnoc.com
+    - export CONTAINER_NAME=$CI_REGISTRY_IMAGE:$CI_BUILD_REF_NAME
+  script:
+    - docker login -u gitlab-ci-token -p $CI_BUILD_TOKEN $REG_NAME 
+    - docker build --pull -t $CONTAINER_NAME .
+    - docker push $CONTAINER_NAME
+  tags:
+    - shell

Dockerfile

+FROM alpine:latest
+
+RUN set -ex \
+    && apk add --no-cache git nodejs nodejs-npm chromium python3 \
+    && python3 -m ensurepip \
+    && pip3 install -r requirements.txt\
+    && npm install -g mermaid.cli \
+
+WORKDIR /docs
+VOLUME /docs

requirements.txt

+mkdocs==1.1.2