Resolve "Improve pipeline speed"

Description

Related Issue

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

Closes #126 (closed)

build/ci/.build-container.yml

 variables:
   DOCKER_TLS_CERTDIR: "/certs"
 
-build_testing:
-  before_script:
-    - echo "override global before script"
-  stage: build
-  allow_failure: false
-  needs: []
-  tags:
-    - shell-builder
-  script:
-    - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
-    - docker build --build-arg GITLAB_USER=$GO_MODULES_USER --build-arg GITLAB_TOKEN=$GO_MODULES_ACCESS_TOKEN -f Dockerfile_testing -t registry.code.fbi.h-da.de/cocsn/gosdn:testing_${CI_PIPELINE_ID} .
-    - docker push registry.code.fbi.h-da.de/cocsn/gosdn:testing_${CI_PIPELINE_ID}
-
 .build: &build
   before_script:
     - echo "override global before script"
@@ -23,11 +10,13 @@ build_testing:
   tags:
     - shell-builder
   script:
-    - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
-    - docker build --build-arg GITLAB_USER=$GO_MODULES_USER --build-arg GITLAB_TOKEN=$GO_MODULES_ACCESS_TOKEN --build-arg BUILDARGS=$BUILDARGS -t $DOCKER_IMAGE_SHA .
-    - docker push $DOCKER_IMAGE_SHA
-    - docker tag $DOCKER_IMAGE_SHA $TAG
-    - docker push $TAG
+   - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
+   - docker build --build-arg GITLAB_USER=$GO_MODULES_USER --build-arg GITLAB_TOKEN=$GO_MODULES_ACCESS_TOKEN --build-arg BUILDARGS=$BUILDARGS -t $DOCKER_IMAGE_SHA .
+   - docker push $DOCKER_IMAGE_SHA
+   - docker tag $DOCKER_IMAGE_SHA $TAG
+   - docker push $TAG
+   - docker build --target installer --build-arg GITLAB_USER=$GO_MODULES_USER --build-arg GITLAB_TOKEN=$GO_MODULES_ACCESS_TOKEN --build-arg BUILDARGS=$BUILDARGS -t registry.code.fbi.h-da.de/cocsn/gosdn:testing_${CI_PIPELINE_ID} .
+   - docker push registry.code.fbi.h-da.de/cocsn/gosdn:testing_${CI_PIPELINE_ID}
 
 build:develop:
   variables: