Use gorilla/mux for middleware and extend

- Use gorilla/mux for middleware.
- Add Dumper, RequestID, and Logger middlewares.
- Add makeURL helper

internal/middleware/dumper.go

@@ -0,0 +1,124 @@
+package middleware
+
+// Derived from from the Goa project, MIT Licensed
+// https://github.com/goadesign/goa/blob/v3/http/middleware/debug.go
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"sort"
+	"strings"
+
+	"github.com/gorilla/mux"
+)
+
+// responseDupper tees the response to a buffer and a response writer.
+type responseDupper struct {
+	http.ResponseWriter
+	Buffer *bytes.Buffer
+	Status int
+}
+
+// Dumper returns a debug middleware which prints detailed information about
+// incoming requests and outgoing responses including all headers, parameters
+// and bodies.
+func Dumper(w io.Writer) func(http.Handler) http.Handler {
+	return func(h http.Handler) http.Handler {
+		return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+			buf := &bytes.Buffer{}
+			// Request ID
+			rid := r.Context().Value(RequestIDKey)
+
+			// Request URL
+			buf.WriteString(fmt.Sprintf("> [%s] %s %s", rid, r.Method, r.URL.String()))
+
+			// Request Headers
+			keys := make([]string, len(r.Header))
+			i := 0
+			for k := range r.Header {
+				keys[i] = k
+				i++
+			}
+			sort.Strings(keys)
+			for _, k := range keys {
+				buf.WriteString(fmt.Sprintf("\n> [%s] %s: %s", rid, k, strings.Join(r.Header[k], ", ")))
+			}
+
+			// Request parameters
+			params := mux.Vars(r)
+			keys = make([]string, len(params))
+			i = 0
+			for k := range params {
+				keys[i] = k
+				i++
+			}
+			sort.Strings(keys)
+			for _, k := range keys {
+				buf.WriteString(fmt.Sprintf("\n> [%s] %s: %s", rid, k, strings.Join(r.Header[k], ", ")))
+			}
+
+			// Request body
+			b, err := ioutil.ReadAll(r.Body)
+			if err != nil {
+				b = []byte("failed to read body: " + err.Error())
+			}
+			if len(b) > 0 {
+				buf.WriteByte('\n')
+				lines := strings.Split(string(b), "\n")
+				for _, line := range lines {
+					buf.WriteString(fmt.Sprintf("> [%s] %s\n", rid, line))
+				}
+			}
+			r.Body = ioutil.NopCloser(bytes.NewBuffer(b))
+
+			dupper := &responseDupper{ResponseWriter: rw, Buffer: &bytes.Buffer{}}
+			h.ServeHTTP(dupper, r)
+
+			buf.WriteString(fmt.Sprintf("\n< [%s] %s", rid, http.StatusText(dupper.Status)))
+			keys = make([]string, len(dupper.Header()))
+			i = 0
+			for k := range dupper.Header() {
+				keys[i] = k
+				i++
+			}
+			sort.Strings(keys)
+			for _, k := range keys {
+				buf.WriteString(fmt.Sprintf("\n< [%s] %s: %s", rid, k, strings.Join(dupper.Header()[k], ", ")))
+			}
+			if dupper.Buffer.Len() > 0 {
+				buf.WriteByte('\n')
+				lines := strings.Split(dupper.Buffer.String(), "\n")
+				for _, line := range lines {
+					buf.WriteString(fmt.Sprintf("< [%s] %s\n", rid, line))
+				}
+			}
+			buf.WriteByte('\n')
+			w.Write(buf.Bytes())
+		})
+	}
+}
+
+// Write writes the data to the buffer and connection as part of an HTTP reply.
+func (r *responseDupper) Write(b []byte) (int, error) {
+	r.Buffer.Write(b)
+	return r.ResponseWriter.Write(b)
+}
+
+// WriteHeader records the status and sends an HTTP response header with status code.
+func (r *responseDupper) WriteHeader(s int) {
+	r.Status = s
+	r.ResponseWriter.WriteHeader(s)
+}
+
+// Hijack supports the http.Hijacker interface.
+func (r *responseDupper) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	if hijacker, ok := r.ResponseWriter.(http.Hijacker); ok {
+		return hijacker.Hijack()
+	}
+	return nil, nil, fmt.Errorf("dumper middleware: inner ResponseWriter cannot be hijacked: %T", r.ResponseWriter)
+}

internal/middleware/logger.go

@@ -0,0 +1,59 @@
+package middleware
+
+import (
+	"bytes"
+	"fmt"
+	"log"
+	"net/http"
+	"time"
+
+	"github.com/dustin/go-humanize"
+	"github.com/go-chi/chi/middleware"
+)
+
+// Logger is a middleware that logs useful data about each HTTP request.
+type Logger struct {
+	Logger middleware.LoggerInterface
+}
+
+// NewLogger creates a new RequestLogger Handler.
+func NewLogger() func(next http.Handler) http.Handler {
+	return middleware.RequestLogger(&Logger{})
+}
+
+// NewLogEntry creates a new LogEntry for the request.
+func (l *Logger) NewLogEntry(r *http.Request) middleware.LogEntry {
+	e := &LogEntry{
+		req: r,
+		buf: &bytes.Buffer{},
+	}
+
+	return e
+}
+
+// LogEntry represents an individual log entry.
+type LogEntry struct {
+	*Logger
+	req *http.Request
+	buf *bytes.Buffer
+}
+
+// Write constructs and writes the final log entry.
+func (l *LogEntry) Write(status, bytes int, elapsed time.Duration) {
+	rid := GetReqID(l.req.Context())
+	if rid != "" {
+		fmt.Fprintf(l.buf, "[%s] ", rid)
+	}
+
+	fmt.Fprintf(l.buf, "%03d | %s | %s | ", status, humanize.IBytes(uint64(bytes)), elapsed)
+	l.buf.WriteString(l.req.Host + " | " + l.req.Method + " " + l.req.RequestURI)
+	log.Print(l.buf.String())
+}
+
+/// Panic prints the call stack for a panic.
+func (l *LogEntry) Panic(v interface{}, stack []byte) {
+	e := l.NewLogEntry(l.req).(*LogEntry)
+	fmt.Fprintf(e.buf, "panic: %#v", v)
+	log.Print(e.buf.String())
+	log.Print(string(stack))
+}

internal/middleware/request_id.go

@@ -0,0 +1,98 @@
+package middleware
+
+// Derived from Goa project, MIT Licensed
+// https://github.com/goadesign/goa/blob/v3/http/middleware/requestid.go
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/gofrs/uuid"
+)
+
+// Key to use when setting the request ID.
+type ctxKeyRequestID int
+
+// RequestIDKey is the key that holds the unique request ID in a request context.
+const RequestIDKey ctxKeyRequestID = 0
+
+// RequestID is a middleware that injects a request ID into the context of each
+// request.
+func RequestID(options ...RequestIDOption) func(http.Handler) http.Handler {
+	o := newRequestIDOptions(options...)
+
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			ctx := r.Context()
+
+			var id string
+
+			if o.UseRequestID() {
+				id = r.Header.Get("X-Request-Id")
+				if o.requestIDLimit > 0 && len(id) > o.requestIDLimit {
+					id = id[:o.requestIDLimit]
+				}
+			}
+
+			if id == "" {
+				id = uuid.Must(uuid.NewV4()).String()[:6]
+			}
+
+			ctx = context.WithValue(ctx, RequestIDKey, id)
+			next.ServeHTTP(w, r.WithContext(ctx))
+		})
+	}
+}
+
+// GetReqID returns a request ID from the given context if one is present.
+// Returns the empty string if a request ID cannot be found.
+func GetReqID(ctx context.Context) string {
+	if ctx == nil {
+		return ""
+	}
+	if reqID, ok := ctx.Value(RequestIDKey).(string); ok {
+		return reqID
+	}
+	return ""
+}
+
+func UseXRequestIDHeaderOption(f bool) RequestIDOption {
+	return func(o *RequestIDOptions) *RequestIDOptions {
+		o.useXRequestID = f
+		return o
+	}
+}
+
+func XRequestIDLimitOption(limit int) RequestIDOption {
+	return func(o *RequestIDOptions) *RequestIDOptions {
+		o.requestIDLimit = limit
+		return o
+	}
+}
+
+type (
+	RequestIDOption func(*RequestIDOptions) *RequestIDOptions
+
+	RequestIDOptions struct {
+		// useXRequestID enabled the use of the X-Request-Id request header as
+		// the request ID.
+		useXRequestID bool
+
+		// requestIDLimit is the maximum length of the X-Request-Id header
+		// allowed. Values longer than this value are truncated. Zero value
+		// means no limit.
+		requestIDLimit int
+	}
+)
+
+func newRequestIDOptions(options ...RequestIDOption) *RequestIDOptions {
+	o := new(RequestIDOptions)
+	for _, opt := range options {
+		o = opt(o)
+	}
+	return o
+}
+
+func (o *RequestIDOptions) UseRequestID() bool {
+	return o.useXRequestID
+}