如何在GitLab Pipeline中检查API调用的JSON响应并执行后续操作

需求：在create_merge_request阶段检查创建合并请求的API响应，获取合并请求ID后执行合并操作，无需依赖外部工具，直接在GitLab Pipeline内完成。

优化后的多阶段CI配置 #

stages:
  - create_branch
  - create_merge_request
  - merge_merge_request

create_branch:
  stage: create_branch
  script:
    - git checkout -b new-feature-branch
    - git push origin new-feature-branch
  only:
    - master

create_merge_request:
  stage: create_merge_request
  script:
    - |
      # 调用API创建合并请求并捕获响应
      MR_RESPONSE=$(curl --request POST --header "PRIVATE-TOKEN: $GITLAB_TOKEN" \
      --data "source_branch=new-feature-branch&target_branch=master&title=New Feature" \
      "https://gitlab.com/api/v4/projects/${CI_PROJECT_ID}/merge_requests")
      # 从响应中提取MR ID并写入文件
      echo "$MR_RESPONSE" | jq '.id' > mr_id.txt
      # 验证合并请求是否创建成功
      if [ -z "$(cat mr_id.txt)" ]; then
        echo "合并请求创建失败"
        exit 1
      fi
  artifacts:
    paths:
      - mr_id.txt
    expire_in: 1 hour
  only:
    - master
  needs:
    - create_branch

merge_merge_request:
  stage: merge_merge_request
  script:
    - |
      # 从传递的工件中读取MR ID
      MR_ID=$(cat mr_id.txt)
      # 调用API触发合并，设置流水线成功后自动合并
      curl --request PUT --header "PRIVATE-TOKEN: $GITLAB_TOKEN" \
      --data "merge_when_pipeline_succeeds=true" \
      "https://gitlab.com/api/v4/projects/${CI_PROJECT_ID}/merge_requests/$MR_ID/merge"
  only:
    - master
  needs:
    - create_merge_request

关键改进点 #

• 直接捕获MR ID：在创建合并请求的阶段直接从API响应提取ID，通过GitLab的artifacts机制传递给后续阶段，避免重复查询API，更高效且可靠。
• 增加有效性校验：检查提取的MR ID是否为空，若为空则终止流水线，防止后续阶段执行无效操作。
• 简化合并阶段逻辑：直接读取传递的MR ID，无需再次调用查询接口。

可选：单阶段完成创建与合并 #

如果不需要拆分阶段，也可以在同一个步骤内完成创建和合并操作：

stages:
  - create_branch
  - create_and_merge_mr

create_branch:
  stage: create_branch
  script:
    - git checkout -b new-feature-branch
    - git push origin new-feature-branch
  only:
    - master

create_and_merge_mr:
  stage: create_and_merge_mr
  script:
    - |
      # 创建合并请求并获取响应
      MR_RESPONSE=$(curl --request POST --header "PRIVATE-TOKEN: $GITLAB_TOKEN" \
      --data "source_branch=new-feature-branch&target_branch=master&title=New Feature" \
      "https://gitlab.com/api/v4/projects/${CI_PROJECT_ID}/merge_requests")
      MR_ID=$(echo "$MR_RESPONSE" | jq '.id')
      
      # 验证合并请求创建成功
      if [ -z "$MR_ID" ]; then
        echo "合并请求创建失败"
        exit 1
      fi
      
      # 触发合并操作
      curl --request PUT --header "PRIVATE-TOKEN: $GITLAB_TOKEN" \
      --data "merge_when_pipeline_succeeds=true" \
      "https://gitlab.com/api/v4/projects/${CI_PROJECT_ID}/merge_requests/$MR_ID/merge"
  only:
    - master
  needs:
    - create_branch

内容的提问来源于stack exchange，提问作者Advik Mehta