Variables

Covered Gitlab features : variables

Like "Perceval de Galles" says, "what’s matters is the value". It’s of course better in French with "De toute façon, ce qui compte, c’est les valeurs". This is a rule coming from the famous game called the Sirop. Here, we will see how much the value and variables are important in our quest of the great CI.

sirop

Est-ce que vous avez assez de dés pour remplir un seau comme ça ? [Le tavernier n’en a que trois] C’est plus facile d’en tirer cent ou deux-cents d’un coup et d’additionner, parce que là avec trois, on va être obligés de tirer quarante fois de suite à chaque tour.

— Perceval
Kaamelott S03E50

Global Variable(s)

You will use the project created at the previous step

The main goal is to simplify each of your jobs by using variables

📝 Instructions

➡️ Edit the the .gitlab-ci.yml

➡️ Add, at the top of the file a key name variables:

➡️ Add a key inside the variables block named MAVEN_OPTS with the following value:

"-Dhttps.protocols=TLSv1.2 -Dmaven.color=false -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=WARN -Dorg.slf4j.simpleLogger.showDateTime=true -Djava.awt.headless=true"

➡️ Add another key inside the variables block named MAVEN_CLI_OPTS with the following value:

"--batch-mode --errors --fail-at-end --show-version -DinstallAtEnd=true -DdeployAtEnd=true"
You can use the value MAVEN_OPTS and MAVEN_CLI_OPTS in any of your jobs and so, they can be accessed by any executable 👍
Those values are advised by Maven project when running inside a Continuous Integration System

➡️ Replace all the ./mvnw --batch-mode in the file by ./mvnw $MAVEN_CLI_OPTS in each job. You should have something looking like this

image: openjdk:8-jdk-slim

variables:
  MAVEN_OPTS: "-Dhttps.protocols=TLSv1.2 -Dmaven.color=false -Dmaven.repo.local=.m2/repository -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=WARN -Dorg.slf4j.simpleLogger.showDateTime=true -Djava.awt.headless=true"
  MAVEN_CLI_OPTS: "--batch-mode --errors --fail-at-end --show-version -DinstallAtEnd=true -DdeployAtEnd=true"

stages:
  - tests
  - build

build:
  stage: build
  script:
    - ./mvnw $MAVEN_CLI_OPTS install -DskipTests

unit:
  stage: tests
  script:
    - ./mvnw $MAVEN_CLI_OPTS test -Dtests.tags="unit"

e2e:
  stage: tests
  script:
    - ./mvnw $MAVEN_CLI_OPTS test -Dtests.tags="e2e"

➡️ Use git to commit and push your modifications :

git add .
git commit -m "chore(ci): add global variables to configure maven"
git push


🚨 Solution

Project : https://gitlab.com/gitlab-workshop/solutions/blob/49ff6f2a0852703028df8360194d47aa7dca99d0/ // REF(variables:global)

Pipeline : https://gitlab.com/gitlab-workshop/solutions/pipelines/275966699 // REF(variables:global)

Local Variable(s)

📝 Instructions

In the previous step, we leverage the power of global variable to simplify our CI scripts. In this step we will define some variables just for one job.

➡️ Edit the the .gitlab-ci.yml

➡️ Add a variables block inside the unit job

➡️ Add a key name SCOPE with value unit

➡️ Add a variables block inside the e2e job

➡️ Add a key name SCOPE with value e2e

➡️ Remove in each script block the parameter -Dtests.tags="…​"

➡️ We should have a .gitlab-ci.yml like this

image: openjdk:8-jdk-slim

variables:
  MAVEN_OPTS: "-Dhttps.protocols=TLSv1.2 -Dmaven.color=false -Dmaven.repo.local=.m2/repository -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=WARN -Dorg.slf4j.simpleLogger.showDateTime=true -Djava.awt.headless=true"
  MAVEN_CLI_OPTS: "--batch-mode --errors --fail-at-end --show-version -DinstallAtEnd=true -DdeployAtEnd=true"

stages:
  - tests
  - build

build:
  stage: build
  script:
    - ./mvnw $MAVEN_CLI_OPTS install -DskipTests

unit:
  stage: tests
  variables:
    SCOPE: unit
  script:
    - ./mvnw $MAVEN_CLI_OPTS test

e2e:
  stage: tests
  variables:
    SCOPE: e2e
  script:
    - ./mvnw $MAVEN_CLI_OPTS test
The SCOPE variable trigger a specific profile in Maven enabling a specific set of tests

➡️ Use git to commit and push your modifications :

git add .
git commit -m "chore(ci): add local variables to configure maven tests"
git push


🚨 Solution

Project : https://gitlab.com/gitlab-workshop/solutions/blob/633b69483e2ab2fcd915b4881966bad1a2c6edf3/ // REF(variables:local)

Pipeline : https://gitlab.com/gitlab-workshop/solutions/pipelines/275966834 // REF(variables:local)

Environment Variable(s)

Some variables are too sensible to be put under git version control. So, we can use a feature provided by Gitlab to host some variables out of the git and still be able to reference it from the .gitlab-ci.yml.

Mainly, those variables are credentials which shouldn’t be exposed to everyone

In this step, we will publish our application as a docker image in the Gitlab docker registry.

📝 Instructions

➡️ Go to the CI/CD Settings of your project

https://gitlab.com/gitlab-workshop/swiss-institute-of-bioinformatics/<your-project>/settings/ci_cd

➡️ Add REGISTRY_USER variable with following value : gitlab-ci-token. The variable should not be masked.

env variables
Don’t forget to save 😊

➡️ Modify the command in the build job to trigger a docker image creation

./mvnw $MAVEN_CLI_OPTS clean compile jib:build

➡️ Use git to commit and push your modifications :

git add .
git commit -m "chore(ci): add global variables to publish application in the gitlab docker registry"
git push

➡️ Follow your job execution using :

https://gitlab.com/gitlab-workshop/swiss-institute-of-bioinformatics/<your-project>/-/jobs

➡️ View your deployed image on Gitlab docker registry using :

https://gitlab.com/gitlab-workshop/swiss-institute-of-bioinformatics/<your-project>/container_registry

Jib permits to build java docker images without the docker binary, read this great article (french only) for more information
REGISTRY_USER environment variable is used in the pom.xml file here

🚨 Solution

Project : https://gitlab.com/gitlab-workshop/solutions/blob/30cd289c7b199f89e480355a3096c829983ffa6c/ // REF(variables:env)

Pipeline : https://gitlab.com/gitlab-workshop/solutions/pipelines/275966948 // REF(variables:env)

Registry : https://gitlab.com/gitlab-workshop/solutions/container_registry

Predefined Variables

You could also use predefined variables

Theses variables are provided by the Gitlab runner and can be used in your jobs.

📝 Instructions

➡️ Edit your .gitlab-ci.yml and modify your SCOPE variable values with : $CI_JOB_NAME

➡️ Use git to commit and push your modifications :

git add .
git commit -m "chore(ci): use job name as scope for triggering tests"
git push
The C.I now use the job name as value for your test SCOPE variable


🚨 Solution

Project : https://gitlab.com/gitlab-workshop/solutions/blob/fafa8e51fdcfa76f79864e9e6f4aac83f4e5fc89/ // REF(variables:predefined)

Pipeline : https://gitlab.com/gitlab-workshop/solutions/pipelines/275967079 // REF(variables:predefined)