CI: separate mono installation

Mono installation takes a long time and currently our CI
has to do it almost 4 times which causes the CI to take
forever to build, test and package a commit so to mitigate
this issue this commit separates mono installation into
a separate stage and uploads the resulting docker image
into Gitlab's Container Registry and then we use that
docker image for the rest of the stages.

See merge request https://gitlab.com/nblockchain/geewallet/-/merge_requests/123

.gitlab-ci.yml

@@ -1,21 +1,24 @@
-before_script:
-  - apt-get update
-  - apt install -y make git
-  # needed to download NuGet
-  - apt-get install -y curl
-
 stages:
+  - buildenv
   - build
   - unit_tests
   - integration_tests
   - package
 
+stockmono_buildenv:
+  image: docker:19.03.12
+  stage: buildenv
+  services:
+    - docker:19.03.12-dind
+  script:
+    - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
+    - docker build -t $CI_REGISTRY_IMAGE/stock_env:$CI_COMMIT_SHA -f stockmono.docker .
+    - docker push $CI_REGISTRY_IMAGE/stock_env:$CI_COMMIT_SHA
+
 stockmono_build:
-  image: ubuntu:20.04
+  image: $CI_REGISTRY_IMAGE/stock_env:$CI_COMMIT_SHA
   stage: build
   script:
-    # https://askubuntu.com/a/1013396
-    - DEBIAN_FRONTEND=noninteractive apt-get install -y mono-complete mono-xbuild fsharp
     - mono --version
 
     - ./configure.sh
@@ -25,40 +28,43 @@ stockmono_build:
     - make install
 
 stockmono_test_unit:
-  image: ubuntu:20.04
+  image: $CI_REGISTRY_IMAGE/stock_env:$CI_COMMIT_SHA
   stage: unit_tests
   script:
-    # https://askubuntu.com/a/1013396
-    - DEBIAN_FRONTEND=noninteractive apt-get install -y mono-complete mono-xbuild fsharp
     - mono --version
 
-    - apt-get install -y nunit-console
     - ./configure.sh
     - make
     - make check
 
 stockmono_test_integration:
-  image: ubuntu:20.04
+  image: $CI_REGISTRY_IMAGE/stock_env:$CI_COMMIT_SHA
   stage: integration_tests
   script:
-    # https://askubuntu.com/a/1013396
-    - DEBIAN_FRONTEND=noninteractive apt-get install -y mono-complete mono-xbuild fsharp
     - mono --version
 
     - ./configure.sh
     - make
     - make update-servers
 
+newmono_buildenv:
+  image: docker:19.03.12
+  stage: buildenv
+  services:
+    - docker:19.03.12-dind
+  script:
+    - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
+    - docker build -t $CI_REGISTRY_IMAGE/new_env:$CI_COMMIT_SHA -f newmono.docker .
+    - docker push $CI_REGISTRY_IMAGE/new_env:$CI_COMMIT_SHA
+
 newmono_build:
-  image: ubuntu:20.04
+  image: $CI_REGISTRY_IMAGE/new_env:$CI_COMMIT_SHA
   stage: build
   artifacts:
     paths:
       - bin/*.zip
     expire_in: 50days
   script:
-    - ./scripts/install_mono_from_microsoft_deb_packages.sh
-
     - ./configure.sh
     - make sanitycheck
     - make strict
@@ -67,25 +73,19 @@ newmono_build:
     # so that we log the version of nuget for when it works
     - make nuget
 
-    - apt-get install -y zip
     - make zip
 
 newmono_test_unit:
-  image: ubuntu:20.04
+  image: $CI_REGISTRY_IMAGE/new_env:$CI_COMMIT_SHA
   stage: unit_tests
   script:
-    - ./scripts/install_mono_from_microsoft_deb_packages.sh
-
-    - apt install -y nunit-console
 
     - time (./configure.sh && make && make check)
 
 newmono_test_integration:
-  image: ubuntu:20.04
+  image: $CI_REGISTRY_IMAGE/new_env:$CI_COMMIT_SHA
   stage: integration_tests
   script:
-    - ./scripts/install_mono_from_microsoft_deb_packages.sh
-
     - ./configure.sh &&
       make &&
       make update-servers

CONTRIBUTING.md

@@ -198,7 +198,3 @@ Some other items that haven't been prioritized include (likely only intelligible
   * https://github.com/stroiman/JsonFSharp
 - Paranoid-build mode: instead of binary nuget deps, use either git submodules, or [local nugets](https://github.com/mono/mono-addins/issues/73#issuecomment-389343246) (maybe depending on [this RFE](https://github.com/dotnet/sdk/issues/1151) or any workaround mentioned there, or a config file like it's explained here: https://docs.microsoft.com/en-us/nuget/consume-packages/configuring-nuget-behavior), or [source-only nugets](https://medium.com/@attilah/source-code-only-nuget-packages-8f34a8fb4738).
 - Maybe replace JsonRpcSharp with https://www.nuget.org/packages/StreamJsonRpc .
-- Reduce GitLabCI pipeline times by trying one of these two solutions:
-  * Installing deps in docker image and passing it as an artifact: https://forum.gitlab.com/t/passing-docker-image-between-build-and-test-stage-in-gitlab-runner/2444/7
-  * Try GitLabCI's parent-child pipelines: maybe the parent pipeline that defines the 'trigger' element can have a 'script' element too?
-

newmono.docker

@@ -0,0 +1,8 @@
+FROM ubuntu:20.04
+
+COPY "./scripts/install_mono_from_microsoft_deb_packages.sh" "/tmp/install_mono_from_microsoft_deb_packages.sh"
+
+RUN apt update
+RUN apt install -y make git curl zip
+RUN "/tmp/install_mono_from_microsoft_deb_packages.sh"
+RUN apt install -y nunit-console

stockmono.docker

@@ -0,0 +1,8 @@
+FROM ubuntu:20.04
+
+
+RUN apt update
+RUN apt install -y make git curl zip
+# https://askubuntu.com/a/1013396
+ARG DEBIAN_FRONTEND=noninteractive
+RUN apt install -y mono-complete mono-xbuild fsharp nunit-console