chore: update linting configuration (#154)

- Adopt [revive](https://github.com/mgechev/revive) as the local linter
used by `make lint`
- Update to latest golangci-lint releases for CI

Author: mccutchen

.dockerignore

@@ -1,2 +1,3 @@
-.git
+.*
 dist
+examples

.github/workflows/lint.yaml

@@ -20,6 +20,6 @@ jobs:
       - uses: actions/setup-go@v2
         with:
           go-version: '1.21'
-      - uses: golangci/golangci-lint-action@v3.4.0
+      - uses: golangci/golangci-lint-action@v3.7.0
         with:
-          version: v1.52.2
+          version: v1.55.2

Makefile

@@ -12,10 +12,14 @@ COVERAGE_ARGS ?= -covermode=atomic -coverprofile=$(COVERAGE_PATH)
 TEST_ARGS     ?= -race
 
 # 3rd party tools
-GOLINT      := go run golang.org/x/lint/golint@latest
+LINT        := go run github.com/mgechev/revive@v1.3.4
 REFLEX      := go run github.com/cespare/reflex@v0.3.1
 STATICCHECK := go run honnef.co/go/tools/cmd/staticcheck@2023.1.3
 
+# Host and port to use when running locally via `make run` or `make watch`
+HOST ?= 127.0.0.1
+PORT ?= 8080
+
 
 # =============================================================================
 # build
@@ -45,7 +49,6 @@ test:
 	go test $(TEST_ARGS) ./...
 .PHONY: test
 
-
 # Test command to run for continuous integration, which includes code coverage
 # based on codecov.io's documentation:
 # https://github.com/codecov/example-go/blob/b85638743b972bd0bd2af63421fe513c6f968930/README.md
@@ -61,7 +64,7 @@ testcover: testci
 lint:
 	test -z "$$(gofmt -d -s -e .)" || (echo "Error: gofmt failed"; gofmt -d -s -e . ; exit 1)
 	go vet ./...
-	$(GOLINT) -set_exit_status ./...
+	$(LINT) -set_exit_status ./...
 	$(STATICCHECK) ./...
 .PHONY: lint
 
@@ -70,7 +73,7 @@ lint:
 # run locally
 # =============================================================================
 run: build
-	$(DIST_PATH)/go-httpbin -host 127.0.0.1 -port 8080
+	HOST=$(HOST) PORT=$(PORT) $(DIST_PATH)/go-httpbin
 .PHONY: run
 
 watch:

cmd/go-httpbin/main.go

@@ -1,3 +1,4 @@
+// Package main implements the go-httpbin command line tool.
 package main
 
 import (

examples/custom-instrumentation/main.go

@@ -1,3 +1,4 @@
+// Package main demonstrates how to instrument httpbin with custom metrics.
 package main
 
 import (

httpbin/cmd/cmd.go

@@ -1,3 +1,5 @@
+// Package cmd implements the go-httpbin command line interface as a testable
+// package.
 package cmd
 
 import (

httpbin/doc.go

@@ -0,0 +1,3 @@
+// Package httpbin provides a simple HTTP request and response testing server,
+// modeled on the original httpbin.org Python project.
+package httpbin

httpbin/handlers.go

@@ -19,7 +19,7 @@ import (
 
 var nilValues = url.Values{}
 
-func notImplementedHandler(w http.ResponseWriter, r *http.Request) {
+func notImplementedHandler(w http.ResponseWriter, _ *http.Request) {
 	writeError(w, http.StatusNotImplemented, nil)
 }
 
@@ -34,12 +34,12 @@ func (h *HTTPBin) Index(w http.ResponseWriter, r *http.Request) {
 }
 
 // FormsPost renders an HTML form that submits a request to the /post endpoint
-func (h *HTTPBin) FormsPost(w http.ResponseWriter, r *http.Request) {
+func (h *HTTPBin) FormsPost(w http.ResponseWriter, _ *http.Request) {
 	writeHTML(w, mustStaticAsset("forms-post.html"), http.StatusOK)
 }
 
 // UTF8 renders an HTML encoding stress test
-func (h *HTTPBin) UTF8(w http.ResponseWriter, r *http.Request) {
+func (h *HTTPBin) UTF8(w http.ResponseWriter, _ *http.Request) {
 	writeHTML(w, mustStaticAsset("utf8.html"), http.StatusOK)
 }
 
@@ -80,7 +80,7 @@ func (h *HTTPBin) RequestWithBody(w http.ResponseWriter, r *http.Request) {
 		URL:     getURL(r).String(),
 	}
 
-	if err := parseBody(w, r, resp); err != nil {
+	if err := parseBody(r, resp); err != nil {
 		writeError(w, http.StatusBadRequest, fmt.Errorf("error parsing request body: %w", err))
 		return
 	}
@@ -718,20 +718,20 @@ func (h *HTTPBin) Range(w http.ResponseWriter, r *http.Request) {
 }
 
 // HTML renders a basic HTML page
-func (h *HTTPBin) HTML(w http.ResponseWriter, r *http.Request) {
+func (h *HTTPBin) HTML(w http.ResponseWriter, _ *http.Request) {
 	writeHTML(w, mustStaticAsset("moby.html"), http.StatusOK)
 }
 
 // Robots renders a basic robots.txt file
-func (h *HTTPBin) Robots(w http.ResponseWriter, r *http.Request) {
+func (h *HTTPBin) Robots(w http.ResponseWriter, _ *http.Request) {
 	robotsTxt := []byte(`User-agent: *
 Disallow: /deny
 `)
 	writeResponse(w, http.StatusOK, textContentType, robotsTxt)
 }
 
 // Deny renders a basic page that robots should never access
-func (h *HTTPBin) Deny(w http.ResponseWriter, r *http.Request) {
+func (h *HTTPBin) Deny(w http.ResponseWriter, _ *http.Request) {
 	writeResponse(w, http.StatusOK, textContentType, []byte(`YOU SHOULDN'T BE HERE`))
 }
 
@@ -926,7 +926,7 @@ func (h *HTTPBin) Links(w http.ResponseWriter, r *http.Request) {
 }
 
 // doLinksPage renders a page with a series of N links
-func doLinksPage(w http.ResponseWriter, r *http.Request, n int, offset int) {
+func doLinksPage(w http.ResponseWriter, _ *http.Request, n int, offset int) {
 	w.Header().Add("Content-Type", htmlContentType)
 	w.WriteHeader(http.StatusOK)
 
@@ -988,7 +988,7 @@ func doImage(w http.ResponseWriter, kind string) {
 }
 
 // XML responds with an XML document
-func (h *HTTPBin) XML(w http.ResponseWriter, r *http.Request) {
+func (h *HTTPBin) XML(w http.ResponseWriter, _ *http.Request) {
 	writeResponse(w, http.StatusOK, "application/xml", mustStaticAsset("sample.xml"))
 }
 
@@ -1042,7 +1042,7 @@ func (h *HTTPBin) DigestAuth(w http.ResponseWriter, r *http.Request) {
 }
 
 // UUID - responds with a generated UUID
-func (h *HTTPBin) UUID(w http.ResponseWriter, r *http.Request) {
+func (h *HTTPBin) UUID(w http.ResponseWriter, _ *http.Request) {
 	writeJSON(http.StatusOK, w, uuidResponse{
 		UUID: uuidv4(),
 	})
@@ -1085,7 +1085,7 @@ func (h *HTTPBin) DumpRequest(w http.ResponseWriter, r *http.Request) {
 }
 
 // JSON - returns a sample json
-func (h *HTTPBin) JSON(w http.ResponseWriter, r *http.Request) {
+func (h *HTTPBin) JSON(w http.ResponseWriter, _ *http.Request) {
 	w.Header().Set("Content-Type", jsonContentType)
 	w.WriteHeader(http.StatusOK)
 	w.Write(mustStaticAsset("sample.json"))
@@ -1107,7 +1107,7 @@ func (h *HTTPBin) Bearer(w http.ResponseWriter, r *http.Request) {
 }
 
 // Hostname - returns the hostname.
-func (h *HTTPBin) Hostname(w http.ResponseWriter, r *http.Request) {
+func (h *HTTPBin) Hostname(w http.ResponseWriter, _ *http.Request) {
 	writeJSON(http.StatusOK, w, hostnameResponse{
 		Hostname: h.hostname,
 	})

httpbin/helpers.go

@@ -160,7 +160,7 @@ func parseFiles(fileHeaders map[string][]*multipart.FileHeader) (map[string][]st
 //
 // Note: this function expects callers to limit the the maximum size of the
 // request body. See, e.g., the limitRequestSize middleware.
-func parseBody(w http.ResponseWriter, r *http.Request, resp *bodyResponse) error {
+func parseBody(r *http.Request, resp *bodyResponse) error {
 	defer r.Body.Close()
 
 	// Always set resp.Data to the incoming request body, in case we don't know

httpbin/options.go

@@ -46,6 +46,8 @@ func WithObserver(o Observer) OptionFunc {
 	}
 }
 
+// WithExcludeHeaders sets the headers to exclude in outgoing responses, to
+// prevent possible information leakage.
 func WithExcludeHeaders(excludeHeaders string) OptionFunc {
 	return func(h *HTTPBin) {
 		h.setExcludeHeaders(excludeHeaders)