gitlab-runner - docker in docker (dind) and push to GitLab registry - laravel

Question

I wish to use GitLab Container Registry to temporary store my newly built Docker image; in order to have Docker function (i.e. docker login, docker build, docker push), I applied docker-in-docker executor; then from GitLab Piplelines error messages, I realize I need to place a Dockerfile at project root:-
$ docker build --pull -t $CONTAINER_TEST_IMAGE .
unable to prepare context: unable to evaluate symlinks in Dockerfile path: lstat /builds/xxxxx.com/laravel/Dockerfile: no such file or directory
My Dockerfile includes centos:7, php, nodejs, composer and sass installations. I observe after each commit, GitLab runner will go through the Dockerfile once and install all of them from beginning, which makes the whole build stage very slow and funny - how come I just want to amend 1 word in my project but I need to install so many things again for deployment?
From my imagination, it will be nice if I can pre-build a Docker image from a Dockerfile that contains the installations mentioned above plus Docker (so that docker login, docker build and docker push can work) and stored in the GitLab-runner server, and after each commit, this image can be reused to build the new image to be pushed to GitLab Container Registry.
However, I faced 2 problems:-
1) Even I include Docker installation in the pre-build a Docker image, I cannot systemctl docker start, due to some D-bus problem
Failed to get D-Bus connection: Operation not permitted
moreover some articles also mentioned a docker in container shall not run background services;
2) when I use dind, it will require a Dockerfile at project root; with the pre-build a Docker image, actually I have nothing to do with this Dockerfile at project root; hence is dind a wrong option?
Acutally, what is the proper way to push a Laravel project image to GitLab Container Registry? (where to place those npm install and composer install commands?)
image: docker:latest
services:
- docker:dind
stages:
- build
- test
- deploy
variables:
CONTAINER_TEST_IMAGE: xxxx
CONTAINER_RELEASE_IMAGE: yyyy
before_script:
- docker login -u xxx -p yyy registry.gitlab.com
build:
stage: build
script:
- npm install here?
- docker build --pull -t $CONTAINER_TEST_IMAGE .
- docker push $CONTAINER_TEST_IMAGE

Answer 1

There are many questions in your post. I would like to target them as follows:
You can pre-build a docker image and then use it in your gitlab-ci.yaml file. This can be used to add your specific dependencies.
image: my custom image
services:
- docker:dind
Important to add the service to the configuration.
You problem about trying to run the docker service inside the gitlab-ci.yml. You actually don't need to do that. Gitlab exposes the docker engine to the executor (either via unix:///var/run/docker.sock or tcp://localhost:2375/). Note, that if the runners are executed in a kubernetes environment, you need to specify the DOCKER_HOST as follows:
variable:
DOCKER_HOST: tcp://localhost:2375/
You question about where to place npm install is more a fundamental question about how docker images are build. In short, npm install should be place in the Dockerfile. For a long description, please this for example.
Some references:
https://docs.gitlab.com/ee/ci/docker/using_docker_build.html#use-docker-in-docker-executor
https://nodejs.org/en/docs/guides/nodejs-docker-webapp/