Adds Drone and Github workflow for Grafana's fork

This commit adds the files that are specific to Grafana's fork
that are not intended to be included in the upstream. This
files are already present in the commit history (they were deleted),
but this is an attempt of a fresh start on top of the upstream's `main`.
At the moment, this should the only commit we expect to skip when
sending our changes.

.drone/Tests.Dockerfile

@@ -0,0 +1,2 @@
+FROM golang:alpine as builder
+RUN apk --no-cache add make gcc git cairo-dev musl-dev

.drone/cmd/coverage/main.go

@@ -0,0 +1,98 @@
+package main
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"os"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+type aggregation struct {
+	NumStmts        int
+	NumCoveredStmts int
+}
+
+func (a *aggregation) CoveragePct() string {
+	pct := (float64(a.NumCoveredStmts) / float64(a.NumStmts)) * 100
+	return fmt.Sprintf("%.1f%%", pct)
+}
+
+func main() {
+	covFilename := flag.String("f", "coverage.out", "Output of `go test -coverprofile=coverage.out ./...`")
+	flag.Parse()
+
+	f, err := os.Open(*covFilename)
+	if err != nil {
+		panic(err)
+	}
+
+	agg := make(map[string]*aggregation)
+
+	s := bufio.NewScanner(f)
+	s.Split(bufio.ScanLines)
+
+	s.Scan() // First line specifies the mode; it doesn't affect what we do so we can just skip it.
+
+	for s.Scan() {
+		line := s.Text()
+
+		cols := strings.Fields(line)
+		key := strings.Split(cols[0], ":")[0]
+
+		numStmts, err := strconv.Atoi(cols[1])
+		if err != nil {
+			panic(err)
+		}
+		numTimesCovered, err := strconv.Atoi(cols[2])
+		if err != nil {
+			panic(err)
+		}
+
+		if val, ok := agg[key]; ok {
+			val.NumStmts += numStmts
+			if numTimesCovered > 0 {
+				val.NumCoveredStmts += numStmts
+			}
+		} else {
+			numCoveredStmts := 0
+			if numTimesCovered > 0 {
+				numCoveredStmts = numStmts
+			}
+
+			agg[key] = &aggregation{
+				NumStmts:        numStmts,
+				NumCoveredStmts: numCoveredStmts,
+			}
+		}
+	}
+
+	keys := make([]string, 0, len(agg))
+	for k := range agg {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	fmt.Println("Go coverage report:")
+	fmt.Println("<details>")
+	fmt.Println("<summary>Click to expand.</summary>")
+	fmt.Println("")
+	fmt.Println("| File | % |")
+	fmt.Println("| ---- | - |")
+
+	totalStmts := 0
+	totalCoveredStmts := 0
+
+	for _, k := range keys {
+		a := agg[k]
+		fmt.Printf("| %s | %s |\n", k, a.CoveragePct())
+
+		totalStmts += a.NumStmts
+		totalCoveredStmts += a.NumCoveredStmts
+	}
+
+	fmt.Printf("| total | %.1f%% |\n", (float64(totalCoveredStmts)/float64(totalStmts))*100)
+	fmt.Println("</details>")
+}

.drone/cmd/ghcomment/main.go

@@ -0,0 +1,97 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"io/ioutil"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/shurcooL/githubv4"
+
+	"github.com/go-graphite/carbonapi/drone/pkg/github"
+)
+
+const CommenterLogin = "grafanabot"
+
+func main() {
+	grafanabotPat := getRequiredEnv("GRAFANABOT_PAT")
+
+	repoOwner := getRequiredEnv("DRONE_REPO_OWNER")
+	repoName := getRequiredEnv("DRONE_REPO_NAME")
+
+	pullRequest, err := strconv.Atoi(getRequiredEnv("DRONE_PULL_REQUEST"))
+	if err != nil {
+		panic(err)
+	}
+
+	commentTypeIdentifier := flag.String("id", "", "String that identifies the comment type being submitted")
+	commentBodyFilename := flag.String("bodyfile", "", "A file containing the comment body")
+	flag.Parse()
+
+	if *commentTypeIdentifier == "" {
+		panic("Required argument: -i")
+	}
+	if *commentBodyFilename == "" {
+		panic("Required argument: -b")
+	}
+
+	api := github.NewAPI(context.Background(), grafanabotPat)
+
+	err = minimizeOutdatedComments(api, repoOwner, repoName, pullRequest, *commentTypeIdentifier)
+	if err != nil {
+		panic(err)
+	}
+
+	commentBody, err := ioutil.ReadFile(*commentBodyFilename)
+	if err != nil {
+		panic(err)
+	}
+
+	err = addComment(api, repoOwner, repoName, pullRequest, string(commentBody))
+	if err != nil {
+		panic(err)
+	}
+}
+
+func getRequiredEnv(k string) string {
+	v, p := os.LookupEnv(k)
+	if !p {
+		panic("Missing required env var: " + k)
+	}
+
+	return v
+}
+
+func minimizeOutdatedComments(api *github.API, repoOwner string, repoName string, pullRequestNo int, commentTypeIdentifier string) error {
+	prComments, err := api.ListPullRequestComments(repoOwner, repoName, pullRequestNo)
+	if err != nil {
+		return err
+	}
+
+	for _, comment := range prComments {
+		if comment.Author.Login == CommenterLogin && strings.Contains(comment.Body, commentTypeIdentifier) && !comment.IsMinimized {
+			err := api.MinimizeComment(comment.ID, githubv4.ReportedContentClassifiersOutdated)
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func addComment(api *github.API, repoOwner string, repoName string, pullRequestNo int, commentBody string) error {
+	pullRequestNodeID, err := api.GetPullRequestNodeID(repoOwner, repoName, pullRequestNo)
+	if err != nil {
+		return err
+	}
+
+	_, err = api.AddComment(pullRequestNodeID, commentBody)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

.drone/drone.jsonnet

@@ -0,0 +1,93 @@
+local drone = import 'lib/drone/drone.libsonnet';
+local images = import 'lib/drone/images.libsonnet';
+local triggers = import 'lib/drone/triggers.libsonnet';
+local vault = import 'lib/vault/vault.libsonnet';
+
+local pipeline = drone.pipeline;
+local step = drone.step;
+local withInlineStep = drone.withInlineStep;
+local withStep = drone.withStep;
+local withSteps = drone.withSteps;
+
+local imagePullSecrets = { image_pull_secrets: ['dockerconfigjson'] };
+
+local commentCoverageLintReport = {
+  step: step('coverage + lint', $.commands, image=$.image, environment=$.environment),
+  commands: [
+    // Build drone utilities.
+    'scripts/build-drone-utilities.sh',
+    // Generate the raw coverage report.
+    'go test -coverprofile=coverage.out ./...',
+    // Process the raw coverage report.
+    '.drone/coverage > coverage_report.out',
+    // Generate the lint report.
+    'scripts/generate-lint-report.sh',
+    // Combine the reports.
+    'cat coverage_report.out > report.out',
+    'echo "" >> report.out',
+    'cat lint.out >> report.out',
+    // Submit the comment to GitHub.
+    '.drone/ghcomment -id "Go coverage report:" -bodyfile report.out',
+  ],
+  environment: {
+    GRAFANABOT_PAT: { from_secret: 'gh_token' },
+  },
+  image: images._images.goLint,
+};
+
+local buildAndPushImages = {
+  // step builds the pipeline step to build and push a docker image
+  step(app): step(
+    '%s: build and push' % app,
+    [],
+    image=buildAndPushImages.pluginName,
+    settings=buildAndPushImages.settings(app),
+  ),
+
+  pluginName: 'plugins/gcr',
+
+  // settings generates the CI Pipeline step settings
+  settings(app): {
+    repo: $._repo(app),
+    registry: $._registry,
+    dockerfile: './Dockerfile',
+    json_key: { from_secret: 'gcr_admin' },
+    mirror: 'https://mirror.gcr.io',
+    build_args: ['cmd=' + app],
+  },
+
+  // image generates the image for the given app
+  image(app): $._registry + '/' + $._repo(app),
+
+  _repo(app):: 'kubernetes-dev/' + app,
+  _registry:: 'us.gcr.io',
+};
+
+local runTests = {
+  step: step('run tests', $.commands, image=$.image),
+  commands: [
+    'make test'
+  ],
+  image: images._images.testRunner,
+  settings: {
+
+  }
+};
+
+[
+  pipeline('test')
+  + withStep(runTests.step)
+  + imagePullSecrets
+  + triggers.pr
+  + triggers.main,
+
+  pipeline('coverageLintReport')
+  + withStep(commentCoverageLintReport.step)
+  + triggers.pr,
+]
++ [
+  vault.secret('dockerconfigjson', 'secret/data/common/gcr', '.dockerconfigjson'),
+  vault.secret('gh_token', 'infra/data/ci/github/grafanabot', 'pat'),
+  vault.secret('gcr_admin', 'infra/data/ci/gcr-admin', 'service-account'),
+  vault.secret('argo_token', 'infra/data/ci/argo-workflows/trigger-service-account', 'token'),
+]

.drone/drone.yml

@@ -0,0 +1,79 @@
+---
+depends_on: null
+image_pull_secrets:
+- dockerconfigjson
+kind: pipeline
+name: test
+steps:
+- commands:
+  - make test
+  depends_on: []
+  entrypoint: null
+  environment: {}
+  image: us.gcr.io/kubernetes-dev/carbonapi/test-runner:latest
+  name: run tests
+  settings: {}
+trigger:
+  branch:
+  - main
+  event:
+    include:
+    - pull_request
+    - push
+type: docker
+---
+depends_on: null
+kind: pipeline
+name: coverageLintReport
+steps:
+- commands:
+  - scripts/build-drone-utilities.sh
+  - go test -coverprofile=coverage.out ./...
+  - .drone/coverage > coverage_report.out
+  - scripts/generate-lint-report.sh
+  - cat coverage_report.out > report.out
+  - echo "" >> report.out
+  - cat lint.out >> report.out
+  - .drone/ghcomment -id "Go coverage report:" -bodyfile report.out
+  depends_on: []
+  entrypoint: null
+  environment:
+    GRAFANABOT_PAT:
+      from_secret: gh_token
+  image: golangci/golangci-lint:v1.45
+  name: coverage + lint
+  settings: {}
+trigger:
+  event:
+    include:
+    - pull_request
+type: docker
+---
+get:
+  name: .dockerconfigjson
+  path: secret/data/common/gcr
+kind: secret
+name: dockerconfigjson
+---
+get:
+  name: pat
+  path: infra/data/ci/github/grafanabot
+kind: secret
+name: gh_token
+---
+get:
+  name: service-account
+  path: infra/data/ci/gcr-admin
+kind: secret
+name: gcr_admin
+---
+get:
+  name: token
+  path: infra/data/ci/argo-workflows/trigger-service-account
+kind: secret
+name: argo_token
+---
+kind: signature
+hmac: 786972e7020e02e75b297bf8f7a67669cf11bd5bf02f61ac62ec63d0fca2a6c1
+
+...

.drone/go.mod

@@ -0,0 +1,16 @@
+module github.com/go-graphite/carbonapi/drone
+
+go 1.18
+
+require (
+	github.com/shurcooL/githubv4 v0.0.0-20220520033151-0b4e3294ff00
+	golang.org/x/oauth2 v0.0.0-20220630143837-2104d58473e0
+)
+
+require (
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/shurcooL/graphql v0.0.0-20220606043923-3cf50f8a0a29 // indirect
+	golang.org/x/net v0.0.0-20220706163947-c90051bbdb60 // indirect
+	google.golang.org/appengine v1.6.7 // indirect
+	google.golang.org/protobuf v1.28.0 // indirect
+)