Add new pr-commenter custom task

Part of tektoncd#483

This custom task is meant to be used alongside PR status report updates to add/update/delete a comment equivalent to the Prow one listing job failures with links to logs and the command to re-test.

I initially made an attempt to update the `github-add-comment` task in the catalog to do this (tektoncd/catalog#1051) but decided that a custom task frankly made a lot more sense. Its behavior is a pretty direct emulation of how Prow and Lighthouse do this, looking for existing comments by the bot user with a given tag in the comment, and updating/deleting that comment if it exists, creating a new comment otherwise. It's a bit simplified, and instead of using `ProwJob`s to know what should still be in the comment and what should be removed, it specifically just adds or removes the specific job it's reporting on while preserving whatever else was there.

Signed-off-by: Andrew Bayer <[email protected]>

.gitignore

@@ -10,3 +10,5 @@
 
 # Virtualenv files
 .venv
+
+tekton/ci/custom-tasks/pr-commenter/.bin

tekton/ci/custom-tasks/pr-commenter/.golangci.yml

@@ -0,0 +1,41 @@
+linters-settings:
+  gomodguard:
+    blocked:
+      modules:
+        - github.com/ghodss/yaml:
+            recommendations:
+              - sigs.k8s.io/yaml
+linters:
+  disable-all: true
+  enable:
+  - deadcode
+  - errcheck
+  - gofmt
+  - goimports
+  - gomodguard
+  - gosec
+  - gocritic
+  - revive
+  - misspell
+  - unconvert
+output:
+  uniq-by-line: false
+issues:
+  exclude-rules:
+  - path: _test\.go
+    linters:
+    - errcheck
+    - gosec
+  max-issues-per-linter: 0
+  max-same-issues: 0
+  include:
+  # Enable off-by-default rules for revive requiring that all exported elements have a properly formatted comment.
+  - EXC0012
+  - EXC0014
+run:
+  issues-exit-code: 1
+  build-tags:
+  - e2e
+  skip-files: []
+  skip-dirs: []
+  timeout: 10m

tekton/ci/custom-tasks/pr-commenter/Makefile

@@ -0,0 +1,133 @@
+MODULE   = $(shell env GO111MODULE=on $(GO) list -m)
+DATE    ?= $(shell date +%FT%T%z)
+BIN      = $(CURDIR)/.bin
+
+GOLANGCI_VERSION = v1.47.2
+
+GO           = go
+TIMEOUT_UNIT = 5m
+TIMEOUT_E2E  = 20m
+V = 0
+Q = $(if $(filter 1,$V),,@)
+M = $(shell printf "\033[34;1m🐱\033[0m")
+
+export GO111MODULE=on
+
+COMMANDS=$(patsubst cmd/%,%,$(wildcard cmd/*))
+BINARIES=$(addprefix bin/,$(COMMANDS))
+
+.PHONY: all
+all: fmt $(BINARIES) | $(BIN) ; $(info $(M) building executable…) @ ## Build program binary
+
+$(BIN):
+	@mkdir -p $@
+$(BIN)/%: | $(BIN) ; $(info $(M) building $(PACKAGE)…)
+	$Q tmp=$$(mktemp -d); \
+	   env GO111MODULE=off GOPATH=$$tmp GOBIN=$(BIN) $(GO) get $(PACKAGE) \
+		|| ret=$$?; \
+	   rm -rf $$tmp ; exit $$ret
+
+FORCE:
+
+bin/%: cmd/% FORCE
+	$Q $(GO) build $(LDFLAGS) -v -o $@ ./$<
+
+.PHONY: cross
+cross: amd64 arm arm64 s390x ppc64le ## build cross platform binaries
+
+.PHONY: amd64
+amd64:
+	GOOS=linux GOARCH=amd64 go build $(LDFLAGS) ./cmd/...
+
+.PHONY: arm
+arm:
+	GOOS=linux GOARCH=arm go build $(LDFLAGS) ./cmd/...
+
+.PHONY: arm64
+arm64:
+	GOOS=linux GOARCH=arm64 go build $(LDFLAGS) ./cmd/...
+
+.PHONY: s390x
+s390x:
+	GOOS=linux GOARCH=s390x go build $(LDFLAGS) ./cmd/...
+
+.PHONY: ppc64le
+ppc64le:
+	GOOS=linux GOARCH=ppc64le go build $(LDFLAGS) ./cmd/...
+
+KO = $(or ${KO_BIN},${KO_BIN},$(BIN)/ko)
+$(BIN)/ko: PACKAGE=github.com/google/ko
+
+.PHONY: apply
+apply: | $(KO) ; $(info $(M) ko apply -R -f config/) @ ## Apply config to the current cluster
+	$Q $(KO) apply -R -f config
+
+.PHONY: resolve
+resolve: | $(KO) ; $(info $(M) ko resolve -R -f config/) @ ## Resolve config to the current cluster
+	$Q $(KO) resolve --push=false --oci-layout-path=$(BIN)/oci -R -f config
+
+## Tests
+TEST_UNIT_TARGETS := test-unit-verbose test-unit-race
+test-unit-verbose: ARGS=-v
+test-unit-race:    ARGS=-race
+$(TEST_UNIT_TARGETS): test-unit
+.PHONY: $(TEST_UNIT_TARGETS) test-unit
+test-unit: ## Run unit tests
+	$(GO) test -timeout $(TIMEOUT_UNIT) $(ARGS) ./...
+
+TEST_E2E_TARGETS := test-e2e-short test-e2e-verbose test-e2e-race
+test-e2e-short:   ARGS=-short
+test-e2e-verbose: ARGS=-v
+test-e2e-race:    ARGS=-race
+$(TEST_E2E_TARGETS): test-e2e
+.PHONY: $(TEST_E2E_TARGETS) test-e2e
+test-e2e:  ## Run end-to-end tests
+	$(GO) test -timeout $(TIMEOUT_E2E) -tags e2e $(ARGS) ./test/...
+
+.PHONY: check tests
+check tests: test-unit test-e2e
+## Linters configuration and targets
+# TODO(vdemeester) gofmt and goimports checks (run them with -w and make a diff)
+
+GOLINT = $(BIN)/golint
+$(BIN)/golint: PACKAGE=golang.org/x/lint/golint
+
+.PHONY: golint
+golint: | $(GOLINT) ; $(info $(M) running golint…) @ ## Run golint
+	$Q $(GOLINT) -set_exit_status ./...
+
+.PHONY: vet
+vet: | ; $(info $(M) running go vet…) @ ## Run go vet
+	$Q go vet ./...
+
+GOLANGCILINT = $(BIN)/golangci-lint
+$(BIN)/golangci-lint: ; $(info $(M) getting golangci-lint $(GOLANGCI_VERSION))
+	cd tools; GOBIN=$(BIN) go install github.com/golangci/golangci-lint/cmd/golangci-lint@$(GOLANGCI_VERSION)
+
+.PHONY: golangci-lint
+golangci-lint: | $(GOLANGCILINT) ; $(info $(M) running golangci-lint…) @ ## Run golangci-lint
+	$Q $(GOLANGCILINT) run --max-issues-per-linter=0 --max-same-issues=0 --deadline 5m
+
+GOIMPORTS = $(BIN)/goimports
+$(BIN)/goimports: PACKAGE=golang.org/x/tools/cmd/goimports
+
+.PHONY: goimports
+goimports: | $(GOIMPORTS) ; $(info $(M) running goimports…) ## Run goimports
+	$Q $(GOIMPORTS) -l -e -w pkg cmd
+
+.PHONY: fmt
+fmt: ; $(info $(M) running gofmt…) @ ## Run gofmt on all source files
+	$Q $(GO) fmt ./...
+
+# Misc
+
+.PHONY: clean
+clean: ; $(info $(M) cleaning…)	@ ## Cleanup everything
+	@rm -rf $(BIN)
+	@rm -rf bin
+	@rm -rf test/tests.* test/coverage.*
+
+.PHONY: help
+help:
+	@grep -hE '^[ a-zA-Z0-9_-]+:.*?## .*$$' $(MAKEFILE_LIST) | \
+		awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-17s\033[0m %s\n", $$1, $$2}'

tekton/ci/custom-tasks/pr-commenter/README.md

@@ -0,0 +1,45 @@
+# Dogfooding Job PR Commenter
+
+This folder contains a Custom Task that can be used to comment on tektoncd PRs with information
+about failing Tekton runs in the dogfooding cluster. It will add a new comment with up-to-date
+information on all failing Tekton runs for the PR, pulling information about runs other than the
+one triggering the task from earlier comments, and will delete the comment when updating or when
+all runs have passed.
+
+## Configuration
+
+All configuration of the custom task is done via [environment variables on the deployment](./config/500-controller.yaml).
+The `GITHUB_TOKEN` secret is the same GitHub OAuth token used in a number of other places in dogfooding.
+
+The `RETEST_PREFIX` environment variable is there so that if we, in the future, change the command used
+to re-run a Tekton job from `/test ...` to something else, we just need to change the value in the
+deployment for that to be reflected in the comment.
+
+## Example `Run`
+
+```yaml
+apiVersion: tekton.dev/v1alpha1
+kind: Run
+metadata:
+  name: example-pr-comment
+  namespace: tekton-ci
+spec:
+  ref:
+    apiVersion: custom.tekton.dev/v0
+    kind: PRCommenter
+  params:
+  - name: repo
+    value: plumbing
+  - name: prNumber
+    value: 1234
+  - name: sha
+    value: abcd1234
+  - name: jobName
+    value: check-pr-has-kind-label
+  - name: isSuccess
+    value: "false"
+  - name: isOptional
+    value: "false"
+  - name: logURL
+    value: https://prow.tekton.dev/view/gs/tekton-prow/pr-logs/pull/tektoncd_plumbing/1185/check-pr-has-kind-label/1564708061786935296
+```