Auto rollback with circleci 2.0

config.yml

## 1) GENERATE AN API TOKEN (https://circleci.com/gh/<gh-user>/<gh-repo-name>/edit#api)
## 2) ADD ENV VAR WITH NAME "CIRCLE_API_TOKEN" WITH PREVIOUS GENERATED TOKEN 

version: 2
jobs:
  build: 
    machine: true
    steps:
      - run:
          name: Build App
          command: |
            URL=http://pruu.herokuapp.com/dump/test-circleci
            BODY='{
                      "step" : "build"
                    }'
            curl -X POST ${URL} -H 'Content-Type: application/json' -d "${BODY}"

  unit_test: 
    machine: true
    steps:
      - run:
          name: Unit Tests
          command: |
            URL=http://pruu.herokuapp.com/dump/test-circleci
            BODY='{
                      "step" : "unit_test"
                    }'
            curl -X POST ${URL} -H 'Content-Type: application/json' -d "${BODY}"

  deploy_production: 
    machine: true
    steps:
      - run:
          name: Unit Tests
          command: |
            URL=http://pruu.herokuapp.com/dump/test-circleci
            BODY='{
                      "step" : "deploy_production"
                    }'
            curl -X POST ${URL} -H 'Content-Type: application/json' -d "${BODY}"

  integration_test:
    machine: true
    steps:
      - run:
          name: Integration Test Command
          command: |
            URL=WRONG_URL_FOR_SIMULATE_ERROR
            BODY='{
                      "step" : "integration_test"
                    }'
            curl -X POST ${URL} -H 'Content-Type: application/json' -d "${BODY}"
      - run:
          name: Auto Rollback
          command: |
              curl --user ${CIRCLE_API_TOKEN}: \
                --data build_parameters[CIRCLE_JOB]=deploy_rollback \
                --data revision=$CIRCLE_SHA1 \
                https://circleci.com/api/v1.1/project/github/${CIRCLE_USERNAME}/$CIRCLE_PROJECT_REPONAME/tree/$CIRCLE_BRANCH
          when: on_fail

  deploy_commit: 
    machine: true
    steps:
      - run:
          name: Commit/Finish Deploy
          command: |
            URL=http://pruu.herokuapp.com/dump/test-circleci
            BODY='{
                      "step" : "deploy_commit"
                    }'
            curl -X POST ${URL} -H 'Content-Type: application/json' -d "${BODY}"

  deploy_rollback:
    machine: true
    steps:
      - run:
          name: Rollback Deploy
          command: |
            URL=http://pruu.herokuapp.com/dump/test-circleci
            BODY='{
                      "step" : "deploy_rollback"
                    }'
            curl -X POST ${URL} -H 'Content-Type: application/json' -d "${BODY}"
 
workflows:
  version: 2
  build_publish_deploy:
    jobs:
      - build
      - unit_test:
          requires:
            - build
      - hold_deploy:
          type: approval
          requires:
            - unit_test
      - deploy_production:
          requires:
            - hold_deploy
      - integration_test:
          requires:
            - deploy_production
      - hold_commit:
          type: approval
          requires:
            - integration_test
      - hold_rollback:
          type: approval
          requires:
            - integration_test
      - deploy_commit:
          requires:
            - hold_commit
      - deploy_rollback:
          requires:
            - hold_rollback