Chore: Add CI Pipeline to generate Grafana's OpenAPI specification (#75393)

* chore: move over initial changes from sofia's pr #58029

* chore: remove go_image

* chore: begin removing edition, remove unused imports

* chore: remove edition from swagger_gen.star and generate .drone.yml

* chore: regen drone.yml

* fix: fix order of load statements

* fix: try #2 fix order of load statements

* linter fixes

* chore: add doc comment explaining purpose of new clone_pr_branch step

* fix: add placeholder documentation for ver_mode arg

* attempt #1 to import and use clone_enterprise_step_pr

* Update scripts/drone/pipelines/swagger_gen.star

Co-authored-by: Sofia Papagiannaki <1632407+papagian@users.noreply.github.com>

* attempt #2 to import and use clone_enterprise_step_pr

* fix: fix drone lint err invalid or unknown step dependency

* fix: regen hmac to make drone run

* fix: fix drone lint err

* fix: update swagger-clean cmd in step

* attempt to return non zero exit code

* test to see if pipeline fails

* fix: add git to clone pr branch step

* fix: add git and make to swagger-gen step

* try to rerun drone

* debug: figure out why cannot find make swagger-clean

* debug: see if cd grafana/grafana fixes things

* debug: undo cd grafana/grafana

* debug: add more logging statements

* debug: try and remove cd grafana in swagger-gen

* debug: removed grafana after clone statement; add debug before cloning

* fix: remove disable clone

* regen specs to see if swagger-gen step passes now

* add descriptive error message to swagger-gen step

* remove api-spec.json from .gitignore

* revert backend change, regen spec

* add back backend change, regen specs

* Update scripts/drone/pipelines/swagger_gen.star

Co-authored-by: Sofia Papagiannaki <1632407+papagian@users.noreply.github.com>

* Update scripts/drone/pipelines/swagger_gen.star

Co-authored-by: Sofia Papagiannaki <1632407+papagian@users.noreply.github.com>

* revert gitignore change, set enterprise source to drone source branch

* chore: remove unused variable, change committish var name to source

* testing functionality: make a new BE change without gen spec, pipeline should fail

* test functionality: does removing err msg cause step to fail properly

* test functionality: add back err msg and && after

* chore: remove debug statements from swagger gen step

* chore: remove debug lines from clone_pr_branch step

* test functionality: regen specs, swagger_gen step should pass

* test funcionality: regen specs again ????

* chore: update swagger-gen step err msg

* test functionality: make BE change dont regen spec, swagger gen should fail

* test functionality: regen the specs, swagger-gen should pass

* chore: revert test BE change, regen spec

* chore: remove unused clone step

* chore: regen drone.yml

---------

Co-authored-by: Timur Olzhabayev <timur.olzhabayev@grafana.com>
Co-authored-by: Sofia Papagiannaki <1632407+papagian@users.noreply.github.com>

.drone.yml

@@ -1132,6 +1132,66 @@ volumes:
 clone:
   retries: 3
 depends_on: []
+image_pull_secrets:
+- dockerconfigjson
+kind: pipeline
+name: pr-swagger-gen
+node:
+  type: no-parallel
+platform:
+  arch: amd64
+  os: linux
+services: []
+steps:
+- commands:
+  - apk add --update curl jq bash
+  - is_fork=$(curl "https://$GITHUB_TOKEN@api.github.com/repos/grafana/grafana/pulls/$DRONE_PULL_REQUEST"
+    | jq .head.repo.fork)
+  - if [ "$is_fork" != false ]; then return 1; fi
+  - git clone "https://$${GITHUB_TOKEN}@github.com/grafana/grafana-enterprise.git"
+    grafana-enterprise
+  - cd grafana-enterprise
+  - if git checkout ${DRONE_SOURCE_BRANCH}; then echo "checked out ${DRONE_SOURCE_BRANCH}";
+    elif git checkout main; then echo "git checkout main"; else git checkout main;
+    fi
+  environment:
+    GITHUB_TOKEN:
+      from_secret: github_token
+  image: alpine/git:2.40.1
+  name: clone-enterprise
+- commands:
+  - apk add --update git make
+  - make swagger-clean && make openapi3-gen
+  - for f in public/api-merged.json public/openapi3.json; do git add $f; done
+  - if [ -z "$(git diff --name-only --cached)" ]; then echo "Everything seems up to
+    date!"; else echo "Please ensure the branch is up-to-date, then regenerate the
+    specification by running make swagger-clean && make openapi3-gen" && return 1;
+    fi
+  depends_on:
+  - clone-enterprise
+  environment:
+    GITHUB_TOKEN:
+      from_secret: github_token
+  image: golang:1.20.10-alpine
+  name: swagger-gen
+trigger:
+  event:
+  - pull_request
+  paths:
+    exclude:
+    - docs/**
+    - '*.md'
+    include:
+    - pkg/**
+type: docker
+volumes:
+- host:
+    path: /var/run/docker.sock
+  name: docker
+---
+clone:
+  retries: 3
+depends_on: []
 environment:
   EDITION: oss
 image_pull_secrets:
@@ -4607,6 +4667,6 @@ kind: secret
 name: gcr_credentials
 ---
 kind: signature
-hmac: 93de8a710e23d3f1d31860f9eed34cd841b0a0eb48637971de4e8ce60a7c3df1
+hmac: 29a933affceb9cc39b285d936de9e6327deedbb80f1285fa645d596f89ede442
 
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