1 files changed, 366 insertions, 0 deletions
diff --git a/vendor/github.com/docker/distribution/context/http.go b/vendor/github.com/docker/distribution/context/http.go
new file mode 100644
index 000000000..7d65c8524
--- /dev/null
+++ b/vendor/github.com/docker/distribution/context/http.go
@@ -0,0 +1,366 @@
+package context
+
+import (
+	"errors"
+	"net"
+	"net/http"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/docker/distribution/uuid"
+	"github.com/gorilla/mux"
+	log "github.com/sirupsen/logrus"
+)
+
+// Common errors used with this package.
+var (
+	ErrNoRequestContext        = errors.New("no http request in context")
+	ErrNoResponseWriterContext = errors.New("no http response in context")
+)
+
+func parseIP(ipStr string) net.IP {
+	ip := net.ParseIP(ipStr)
+	if ip == nil {
+		log.Warnf("invalid remote IP address: %q", ipStr)
+	}
+	return ip
+}
+
+// RemoteAddr extracts the remote address of the request, taking into
+// account proxy headers.
+func RemoteAddr(r *http.Request) string {
+	if prior := r.Header.Get("X-Forwarded-For"); prior != "" {
+		proxies := strings.Split(prior, ",")
+		if len(proxies) > 0 {
+			remoteAddr := strings.Trim(proxies[0], " ")
+			if parseIP(remoteAddr) != nil {
+				return remoteAddr
+			}
+		}
+	}
+	// X-Real-Ip is less supported, but worth checking in the
+	// absence of X-Forwarded-For
+	if realIP := r.Header.Get("X-Real-Ip"); realIP != "" {
+		if parseIP(realIP) != nil {
+			return realIP
+		}
+	}
+
+	return r.RemoteAddr
+}
+
+// RemoteIP extracts the remote IP of the request, taking into
+// account proxy headers.
+func RemoteIP(r *http.Request) string {
+	addr := RemoteAddr(r)
+
+	// Try parsing it as "IP:port"
+	if ip, _, err := net.SplitHostPort(addr); err == nil {
+		return ip
+	}
+
+	return addr
+}
+
+// WithRequest places the request on the context. The context of the request
+// is assigned a unique id, available at "http.request.id". The request itself
+// is available at "http.request". Other common attributes are available under
+// the prefix "http.request.". If a request is already present on the context,
+// this method will panic.
+func WithRequest(ctx Context, r *http.Request) Context {
+	if ctx.Value("http.request") != nil {
+		// NOTE(stevvooe): This needs to be considered a programming error. It
+		// is unlikely that we'd want to have more than one request in
+		// context.
+		panic("only one request per context")
+	}
+
+	return &httpRequestContext{
+		Context:   ctx,
+		startedAt: time.Now(),
+		id:        uuid.Generate().String(),
+		r:         r,
+	}
+}
+
+// GetRequest returns the http request in the given context. Returns
+// ErrNoRequestContext if the context does not have an http request associated
+// with it.
+func GetRequest(ctx Context) (*http.Request, error) {
+	if r, ok := ctx.Value("http.request").(*http.Request); r != nil && ok {
+		return r, nil
+	}
+	return nil, ErrNoRequestContext
+}
+
+// GetRequestID attempts to resolve the current request id, if possible. An
+// error is return if it is not available on the context.
+func GetRequestID(ctx Context) string {
+	return GetStringValue(ctx, "http.request.id")
+}
+
+// WithResponseWriter returns a new context and response writer that makes
+// interesting response statistics available within the context.
+func WithResponseWriter(ctx Context, w http.ResponseWriter) (Context, http.ResponseWriter) {
+	if closeNotifier, ok := w.(http.CloseNotifier); ok {
+		irwCN := &instrumentedResponseWriterCN{
+			instrumentedResponseWriter: instrumentedResponseWriter{
+				ResponseWriter: w,
+				Context:        ctx,
+			},
+			CloseNotifier: closeNotifier,
+		}
+
+		return irwCN, irwCN
+	}
+
+	irw := instrumentedResponseWriter{
+		ResponseWriter: w,
+		Context:        ctx,
+	}
+	return &irw, &irw
+}
+
+// GetResponseWriter returns the http.ResponseWriter from the provided
+// context. If not present, ErrNoResponseWriterContext is returned. The
+// returned instance provides instrumentation in the context.
+func GetResponseWriter(ctx Context) (http.ResponseWriter, error) {
+	v := ctx.Value("http.response")
+
+	rw, ok := v.(http.ResponseWriter)
+	if !ok || rw == nil {
+		return nil, ErrNoResponseWriterContext
+	}
+
+	return rw, nil
+}
+
+// getVarsFromRequest let's us change request vars implementation for testing
+// and maybe future changes.
+var getVarsFromRequest = mux.Vars
+
+// WithVars extracts gorilla/mux vars and makes them available on the returned
+// context. Variables are available at keys with the prefix "vars.". For
+// example, if looking for the variable "name", it can be accessed as
+// "vars.name". Implementations that are accessing values need not know that
+// the underlying context is implemented with gorilla/mux vars.
+func WithVars(ctx Context, r *http.Request) Context {
+	return &muxVarsContext{
+		Context: ctx,
+		vars:    getVarsFromRequest(r),
+	}
+}
+
+// GetRequestLogger returns a logger that contains fields from the request in
+// the current context. If the request is not available in the context, no
+// fields will display. Request loggers can safely be pushed onto the context.
+func GetRequestLogger(ctx Context) Logger {
+	return GetLogger(ctx,
+		"http.request.id",
+		"http.request.method",
+		"http.request.host",
+		"http.request.uri",
+		"http.request.referer",
+		"http.request.useragent",
+		"http.request.remoteaddr",
+		"http.request.contenttype")
+}
+
+// GetResponseLogger reads the current response stats and builds a logger.
+// Because the values are read at call time, pushing a logger returned from
+// this function on the context will lead to missing or invalid data. Only
+// call this at the end of a request, after the response has been written.
+func GetResponseLogger(ctx Context) Logger {
+	l := getLogrusLogger(ctx,
+		"http.response.written",
+		"http.response.status",
+		"http.response.contenttype")
+
+	duration := Since(ctx, "http.request.startedat")
+
+	if duration > 0 {
+		l = l.WithField("http.response.duration", duration.String())
+	}
+
+	return l
+}
+
+// httpRequestContext makes information about a request available to context.
+type httpRequestContext struct {
+	Context
+
+	startedAt time.Time
+	id        string
+	r         *http.Request
+}
+
+// Value returns a keyed element of the request for use in the context. To get
+// the request itself, query "request". For other components, access them as
+// "request.<component>". For example, r.RequestURI
+func (ctx *httpRequestContext) Value(key interface{}) interface{} {
+	if keyStr, ok := key.(string); ok {
+		if keyStr == "http.request" {
+			return ctx.r
+		}
+
+		if !strings.HasPrefix(keyStr, "http.request.") {
+			goto fallback
+		}
+
+		parts := strings.Split(keyStr, ".")
+
+		if len(parts) != 3 {
+			goto fallback
+		}
+
+		switch parts[2] {
+		case "uri":
+			return ctx.r.RequestURI
+		case "remoteaddr":
+			return RemoteAddr(ctx.r)
+		case "method":
+			return ctx.r.Method
+		case "host":
+			return ctx.r.Host
+		case "referer":
+			referer := ctx.r.Referer()
+			if referer != "" {
+				return referer
+			}
+		case "useragent":
+			return ctx.r.UserAgent()
+		case "id":
+			return ctx.id
+		case "startedat":
+			return ctx.startedAt
+		case "contenttype":
+			ct := ctx.r.Header.Get("Content-Type")
+			if ct != "" {
+				return ct
+			}
+		}
+	}
+
+fallback:
+	return ctx.Context.Value(key)
+}
+
+type muxVarsContext struct {
+	Context
+	vars map[string]string
+}
+
+func (ctx *muxVarsContext) Value(key interface{}) interface{} {
+	if keyStr, ok := key.(string); ok {
+		if keyStr == "vars" {
+			return ctx.vars
+		}
+
+		if strings.HasPrefix(keyStr, "vars.") {
+			keyStr = strings.TrimPrefix(keyStr, "vars.")
+		}
+
+		if v, ok := ctx.vars[keyStr]; ok {
+			return v
+		}
+	}
+
+	return ctx.Context.Value(key)
+}
+
+// instrumentedResponseWriterCN provides response writer information in a
+// context. It implements http.CloseNotifier so that users can detect
+// early disconnects.
+type instrumentedResponseWriterCN struct {
+	instrumentedResponseWriter
+	http.CloseNotifier
+}
+
+// instrumentedResponseWriter provides response writer information in a
+// context. This variant is only used in the case where CloseNotifier is not
+// implemented by the parent ResponseWriter.
+type instrumentedResponseWriter struct {
+	http.ResponseWriter
+	Context
+
+	mu      sync.Mutex
+	status  int
+	written int64
+}
+
+func (irw *instrumentedResponseWriter) Write(p []byte) (n int, err error) {
+	n, err = irw.ResponseWriter.Write(p)
+
+	irw.mu.Lock()
+	irw.written += int64(n)
+
+	// Guess the likely status if not set.
+	if irw.status == 0 {
+		irw.status = http.StatusOK
+	}
+
+	irw.mu.Unlock()
+
+	return
+}
+
+func (irw *instrumentedResponseWriter) WriteHeader(status int) {
+	irw.ResponseWriter.WriteHeader(status)
+
+	irw.mu.Lock()
+	irw.status = status
+	irw.mu.Unlock()
+}
+
+func (irw *instrumentedResponseWriter) Flush() {
+	if flusher, ok := irw.ResponseWriter.(http.Flusher); ok {
+		flusher.Flush()
+	}
+}
+
+func (irw *instrumentedResponseWriter) Value(key interface{}) interface{} {
+	if keyStr, ok := key.(string); ok {
+		if keyStr == "http.response" {
+			return irw
+		}
+
+		if !strings.HasPrefix(keyStr, "http.response.") {
+			goto fallback
+		}
+
+		parts := strings.Split(keyStr, ".")
+
+		if len(parts) != 3 {
+			goto fallback
+		}
+
+		irw.mu.Lock()
+		defer irw.mu.Unlock()
+
+		switch parts[2] {
+		case "written":
+			return irw.written
+		case "status":
+			return irw.status
+		case "contenttype":
+			contentType := irw.Header().Get("Content-Type")
+			if contentType != "" {
+				return contentType
+			}
+		}
+	}
+
+fallback:
+	return irw.Context.Value(key)
+}
+
+func (irw *instrumentedResponseWriterCN) Value(key interface{}) interface{} {
+	if keyStr, ok := key.(string); ok {
+		if keyStr == "http.response" {
+			return irw
+		}
+	}
+
+	return irw.instrumentedResponseWriter.Value(key)
+}