Add extra linting to validate json files

.gitlab-ci.yml

@@ -7,6 +7,20 @@ variables:
   DOCKER_HOST: tcp://docker:2376
   DOCKER_TLS_CERTDIR: "/certs"
 
+jsonlint:
+  stage: lint
+  image: registry.gitlab.com/pipeline-components/jsonlint:latest
+  tags:
+    - 'docker'
+  rules:
+    - if: '$CI_PIPELINE_SOURCE == "merge_request_event"'
+    - if: '$CI_COMMIT_BRANCH && $CI_OPEN_MERGE_REQUESTS'
+      when: never
+  script:
+    - |
+      find . -not -path './.git/*' -name '*.json' -type f -print0 |
+      parallel --will-cite -k -0 -n1 jsonlint -q
+
 black:
   stage: lint
   image: registry.gitlab.com/pipeline-components/black:latest