Gitlab CI Patterns

1---
2name: gitlab-ci-patterns
3description: Build GitLab CI/CD pipelines with multi-stage workflows, caching, and distributed runners for scalable automation. Use when implementing GitLab CI/CD, optimizing pipeline performance, or setting up automated testing and deployment.
4---
5 
6# GitLab CI Patterns
7 
8Comprehensive GitLab CI/CD pipeline patterns for automated testing, building, and deployment.
9 
10## Do not use this skill when
11 
12- The task is unrelated to gitlab ci patterns
13- You need a different domain or tool outside this scope
14 
15## Instructions
16 
17- Clarify goals, constraints, and required inputs.
18- Apply relevant best practices and validate outcomes.
19- Provide actionable steps and verification.
20- If detailed examples are required, open `resources/implementation-playbook.md`.
21 
22## Purpose
23 
24Create efficient GitLab CI pipelines with proper stage organization, caching, and deployment strategies.
25 
26## Use this skill when
27 
28- Automate GitLab-based CI/CD
29- Implement multi-stage pipelines
30- Configure GitLab Runners
31- Deploy to Kubernetes from GitLab
32- Implement GitOps workflows
33 
34## Basic Pipeline Structure
35 
36```yaml
37stages:
38  - build
39  - test
40  - deploy
41 
42variables:
43  DOCKER_DRIVER: overlay2
44  DOCKER_TLS_CERTDIR: "/certs"
45 
46build:
47  stage: build
48  image: node:20
49  script:
50    - npm ci
51    - npm run build
52  artifacts:
53    paths:
54      - dist/
55    expire_in: 1 hour
56  cache:
57    key: ${CI_COMMIT_REF_SLUG}
58    paths:
59      - node_modules/
60 
61test:
62  stage: test
63  image: node:20
64  script:
65    - npm ci
66    - npm run lint
67    - npm test
68  coverage: '/Lines\s*:\s*(\d+\.\d+)%/'
69  artifacts:
70    reports:
71      coverage_report:
72        coverage_format: cobertura
73        path: coverage/cobertura-coverage.xml
74 
75deploy:
76  stage: deploy
77  image: bitnami/kubectl:latest
78  script:
79    - kubectl apply -f k8s/
80    - kubectl rollout status deployment/my-app
81  only:
82    - main
83  environment:
84    name: production
85    url: https://app.example.com
86```
87 
88## Docker Build and Push
89 
90```yaml
91build-docker:
92  stage: build
93  image: docker:24
94  services:
95    - docker:24-dind
96  before_script:
97    - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
98  script:
99    - docker build -t $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA .
100    - docker build -t $CI_REGISTRY_IMAGE:latest .
101    - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
102    - docker push $CI_REGISTRY_IMAGE:latest
103  only:
104    - main
105    - tags
106```
107 
108## Multi-Environment Deployment
109 
110```yaml
111.deploy_template: &deploy_template
112  image: bitnami/kubectl:latest
113  before_script:
114    - kubectl config set-cluster k8s --server="$KUBE_URL" --insecure-skip-tls-verify=true
115    - kubectl config set-credentials admin --token="$KUBE_TOKEN"
116    - kubectl config set-context default --cluster=k8s --user=admin
117    - kubectl config use-context default
118 
119deploy:staging:
120  <<: *deploy_template
121  stage: deploy
122  script:
123    - kubectl apply -f k8s/ -n staging
124    - kubectl rollout status deployment/my-app -n staging
125  environment:
126    name: staging
127    url: https://staging.example.com
128  only:
129    - develop
130 
131deploy:production:
132  <<: *deploy_template
133  stage: deploy
134  script:
135    - kubectl apply -f k8s/ -n production
136    - kubectl rollout status deployment/my-app -n production
137  environment:
138    name: production
139    url: https://app.example.com
140  when: manual
141  only:
142    - main
143```
144 
145## Terraform Pipeline
146 
147```yaml
148stages:
149  - validate
150  - plan
151  - apply
152 
153variables:
154  TF_ROOT: ${CI_PROJECT_DIR}/terraform
155  TF_VERSION: "1.6.0"
156 
157before_script:
158  - cd ${TF_ROOT}
159  - terraform --version
160 
161validate:
162  stage: validate
163  image: hashicorp/terraform:${TF_VERSION}
164  script:
165    - terraform init -backend=false
166    - terraform validate
167    - terraform fmt -check
168 
169plan:
170  stage: plan
171  image: hashicorp/terraform:${TF_VERSION}
172  script:
173    - terraform init
174    - terraform plan -out=tfplan
175  artifacts:
176    paths:
177      - ${TF_ROOT}/tfplan
178    expire_in: 1 day
179 
180apply:
181  stage: apply
182  image: hashicorp/terraform:${TF_VERSION}
183  script:
184    - terraform init
185    - terraform apply -auto-approve tfplan
186  dependencies:
187    - plan
188  when: manual
189  only:
190    - main
191```
192 
193## Security Scanning
194 
195```yaml
196include:
197  - template: Security/SAST.gitlab-ci.yml
198  - template: Security/Dependency-Scanning.gitlab-ci.yml
199  - template: Security/Container-Scanning.gitlab-ci.yml
200 
201trivy-scan:
202  stage: test
203  image: aquasec/trivy:latest
204  script:
205    - trivy image --exit-code 1 --severity HIGH,CRITICAL $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
206  allow_failure: true
207```
208 
209## Caching Strategies
210 
211```yaml
212# Cache node_modules
213build:
214  cache:
215    key: ${CI_COMMIT_REF_SLUG}
216    paths:
217      - node_modules/
218    policy: pull-push
219 
220# Global cache
221cache:
222  key: ${CI_COMMIT_REF_SLUG}
223  paths:
224    - .cache/
225    - vendor/
226 
227# Separate cache per job
228job1:
229  cache:
230    key: job1-cache
231    paths:
232      - build/
233 
234job2:
235  cache:
236    key: job2-cache
237    paths:
238      - dist/
239```
240 
241## Dynamic Child Pipelines
242 
243```yaml
244generate-pipeline:
245  stage: build
246  script:
247    - python generate_pipeline.py > child-pipeline.yml
248  artifacts:
249    paths:
250      - child-pipeline.yml
251 
252trigger-child:
253  stage: deploy
254  trigger:
255    include:
256      - artifact: child-pipeline.yml
257        job: generate-pipeline
258    strategy: depend
259```
260 
261## Reference Files
262 
263- `assets/gitlab-ci.yml.template` - Complete pipeline template
264- `references/pipeline-stages.md` - Stage organization patterns
265 
266## Best Practices
267 
2681. **Use specific image tags** (node:20, not node:latest)
2692. **Cache dependencies** appropriately
2703. **Use artifacts** for build outputs
2714. **Implement manual gates** for production
2725. **Use environments** for deployment tracking
2736. **Enable merge request pipelines**
2747. **Use pipeline schedules** for recurring jobs
2758. **Implement security scanning**
2769. **Use CI/CD variables** for secrets
27710. **Monitor pipeline performance**
278 
279## Related Skills
280 
281- `github-actions-templates` - For GitHub Actions
282- `deployment-pipeline-design` - For architecture
283- `secrets-management` - For secrets handling
284