docs: contribution guide & makefile (#102)

.pre-commit-config.yaml

@@ -30,3 +30,4 @@ repos:
   hooks:
     - id: go-mod-tidy
     - id: go-fmt
+    - id: go-imports

CONTRIBUTING.md

@@ -10,9 +10,12 @@ By participating to this project, you agree to abide our
 Prerequisites:
 
 - `make`
-- [Go 1.15+](https://golang.org/doc/install)
+- [Go 1.16+](https://golang.org/doc/install)
+- [golangci-lint](https://golangci-lint.run/usage/install/#local-installation)
 - [Docker](https://www.docker.com/) (or [Podman](https://podman.io/))
 - [kind](https://kind.sigs.k8s.io/)
+- [pre-commit](https://pre-commit.com/) (optional)
+- [ngrok](https://ngrok.com/) (optional)
 
 Clone `k8s-image-swapper` anywhere:
 
@@ -37,13 +40,13 @@ make test
 You can create a branch for your changes and try to build from the source as you go:
 
 ```sh
-make build
+make test
 ```
 
 When you are satisfied with the changes, we suggest you run:
 
 ```sh
-make ci
+make fmt lint test
 ```
 
 Which runs all the linters and tests.

Makefile

@@ -0,0 +1,29 @@
+SOURCE_FILES?=./...
+TEST_PATTERN?=.
+TEST_OPTIONS?=
+
+.PHONY: help $(MAKECMDGOALS)
+.DEFAULT_GOAL := help
+
+export GO111MODULE := on
+export GOPROXY = https://proxy.golang.org,direct
+
+help: ## List targets & descriptions
+	@cat Makefile* | grep -E '^[a-zA-Z_-]+:.*?## .*$$' | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'
+
+setup: ## Install dependencies
+	go mod download
+	go mod tidy
+
+test: ## Run tests
+	LC_ALL=C go test $(TEST_OPTIONS) -failfast -race -coverpkg=./... -covermode=atomic -coverprofile=coverage.txt $(SOURCE_FILES) -run $(TEST_PATTERN) -timeout=5m
+
+cover: test ## Run tests and open coverage report
+	go tool cover -html=coverage.txt
+
+fmt: ## gofmt and goimports all go files
+	gofmt -l -w .
+	goimports -l -w .
+
+lint: ## Run linters
+	golangci-lint run