diff options
Diffstat (limited to 'vendor/github.com/docker/distribution/context')
7 files changed, 800 insertions, 0 deletions
diff --git a/vendor/github.com/docker/distribution/context/context.go b/vendor/github.com/docker/distribution/context/context.go new file mode 100644 index 000000000..23cbf5b54 --- /dev/null +++ b/vendor/github.com/docker/distribution/context/context.go @@ -0,0 +1,85 @@ +package context + +import ( + "sync" + + "github.com/docker/distribution/uuid" + "golang.org/x/net/context" +) + +// Context is a copy of Context from the golang.org/x/net/context package. +type Context interface { + context.Context +} + +// instanceContext is a context that provides only an instance id. It is +// provided as the main background context. +type instanceContext struct { + Context + id string // id of context, logged as "instance.id" + once sync.Once // once protect generation of the id +} + +func (ic *instanceContext) Value(key interface{}) interface{} { + if key == "instance.id" { + ic.once.Do(func() { + // We want to lazy initialize the UUID such that we don't + // call a random generator from the package initialization + // code. For various reasons random could not be available + // https://github.com/docker/distribution/issues/782 + ic.id = uuid.Generate().String() + }) + return ic.id + } + + return ic.Context.Value(key) +} + +var background = &instanceContext{ + Context: context.Background(), +} + +// Background returns a non-nil, empty Context. The background context +// provides a single key, "instance.id" that is globally unique to the +// process. +func Background() Context { + return background +} + +// WithValue returns a copy of parent in which the value associated with key is +// val. Use context Values only for request-scoped data that transits processes +// and APIs, not for passing optional parameters to functions. +func WithValue(parent Context, key, val interface{}) Context { + return context.WithValue(parent, key, val) +} + +// stringMapContext is a simple context implementation that checks a map for a +// key, falling back to a parent if not present. +type stringMapContext struct { + context.Context + m map[string]interface{} +} + +// WithValues returns a context that proxies lookups through a map. Only +// supports string keys. +func WithValues(ctx context.Context, m map[string]interface{}) context.Context { + mo := make(map[string]interface{}, len(m)) // make our own copy. + for k, v := range m { + mo[k] = v + } + + return stringMapContext{ + Context: ctx, + m: mo, + } +} + +func (smc stringMapContext) Value(key interface{}) interface{} { + if ks, ok := key.(string); ok { + if v, ok := smc.m[ks]; ok { + return v + } + } + + return smc.Context.Value(key) +} diff --git a/vendor/github.com/docker/distribution/context/doc.go b/vendor/github.com/docker/distribution/context/doc.go new file mode 100644 index 000000000..9b623074e --- /dev/null +++ b/vendor/github.com/docker/distribution/context/doc.go @@ -0,0 +1,89 @@ +// Package context provides several utilities for working with +// golang.org/x/net/context in http requests. Primarily, the focus is on +// logging relevant request information but this package is not limited to +// that purpose. +// +// The easiest way to get started is to get the background context: +// +// ctx := context.Background() +// +// The returned context should be passed around your application and be the +// root of all other context instances. If the application has a version, this +// line should be called before anything else: +// +// ctx := context.WithVersion(context.Background(), version) +// +// The above will store the version in the context and will be available to +// the logger. +// +// Logging +// +// The most useful aspect of this package is GetLogger. This function takes +// any context.Context interface and returns the current logger from the +// context. Canonical usage looks like this: +// +// GetLogger(ctx).Infof("something interesting happened") +// +// GetLogger also takes optional key arguments. The keys will be looked up in +// the context and reported with the logger. The following example would +// return a logger that prints the version with each log message: +// +// ctx := context.Context(context.Background(), "version", version) +// GetLogger(ctx, "version").Infof("this log message has a version field") +// +// The above would print out a log message like this: +// +// INFO[0000] this log message has a version field version=v2.0.0-alpha.2.m +// +// When used with WithLogger, we gain the ability to decorate the context with +// loggers that have information from disparate parts of the call stack. +// Following from the version example, we can build a new context with the +// configured logger such that we always print the version field: +// +// ctx = WithLogger(ctx, GetLogger(ctx, "version")) +// +// Since the logger has been pushed to the context, we can now get the version +// field for free with our log messages. Future calls to GetLogger on the new +// context will have the version field: +// +// GetLogger(ctx).Infof("this log message has a version field") +// +// This becomes more powerful when we start stacking loggers. Let's say we +// have the version logger from above but also want a request id. Using the +// context above, in our request scoped function, we place another logger in +// the context: +// +// ctx = context.WithValue(ctx, "http.request.id", "unique id") // called when building request context +// ctx = WithLogger(ctx, GetLogger(ctx, "http.request.id")) +// +// When GetLogger is called on the new context, "http.request.id" will be +// included as a logger field, along with the original "version" field: +// +// INFO[0000] this log message has a version field http.request.id=unique id version=v2.0.0-alpha.2.m +// +// Note that this only affects the new context, the previous context, with the +// version field, can be used independently. Put another way, the new logger, +// added to the request context, is unique to that context and can have +// request scoped variables. +// +// HTTP Requests +// +// This package also contains several methods for working with http requests. +// The concepts are very similar to those described above. We simply place the +// request in the context using WithRequest. This makes the request variables +// available. GetRequestLogger can then be called to get request specific +// variables in a log line: +// +// ctx = WithRequest(ctx, req) +// GetRequestLogger(ctx).Infof("request variables") +// +// Like above, if we want to include the request data in all log messages in +// the context, we push the logger to a new context and use that one: +// +// ctx = WithLogger(ctx, GetRequestLogger(ctx)) +// +// The concept is fairly powerful and ensures that calls throughout the stack +// can be traced in log messages. Using the fields like "http.request.id", one +// can analyze call flow for a particular request with a simple grep of the +// logs. +package context 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) +} diff --git a/vendor/github.com/docker/distribution/context/logger.go b/vendor/github.com/docker/distribution/context/logger.go new file mode 100644 index 000000000..86c5964e4 --- /dev/null +++ b/vendor/github.com/docker/distribution/context/logger.go @@ -0,0 +1,116 @@ +package context + +import ( + "fmt" + + "github.com/sirupsen/logrus" + "runtime" +) + +// Logger provides a leveled-logging interface. +type Logger interface { + // standard logger methods + Print(args ...interface{}) + Printf(format string, args ...interface{}) + Println(args ...interface{}) + + Fatal(args ...interface{}) + Fatalf(format string, args ...interface{}) + Fatalln(args ...interface{}) + + Panic(args ...interface{}) + Panicf(format string, args ...interface{}) + Panicln(args ...interface{}) + + // Leveled methods, from logrus + Debug(args ...interface{}) + Debugf(format string, args ...interface{}) + Debugln(args ...interface{}) + + Error(args ...interface{}) + Errorf(format string, args ...interface{}) + Errorln(args ...interface{}) + + Info(args ...interface{}) + Infof(format string, args ...interface{}) + Infoln(args ...interface{}) + + Warn(args ...interface{}) + Warnf(format string, args ...interface{}) + Warnln(args ...interface{}) +} + +// WithLogger creates a new context with provided logger. +func WithLogger(ctx Context, logger Logger) Context { + return WithValue(ctx, "logger", logger) +} + +// GetLoggerWithField returns a logger instance with the specified field key +// and value without affecting the context. Extra specified keys will be +// resolved from the context. +func GetLoggerWithField(ctx Context, key, value interface{}, keys ...interface{}) Logger { + return getLogrusLogger(ctx, keys...).WithField(fmt.Sprint(key), value) +} + +// GetLoggerWithFields returns a logger instance with the specified fields +// without affecting the context. Extra specified keys will be resolved from +// the context. +func GetLoggerWithFields(ctx Context, fields map[interface{}]interface{}, keys ...interface{}) Logger { + // must convert from interface{} -> interface{} to string -> interface{} for logrus. + lfields := make(logrus.Fields, len(fields)) + for key, value := range fields { + lfields[fmt.Sprint(key)] = value + } + + return getLogrusLogger(ctx, keys...).WithFields(lfields) +} + +// GetLogger returns the logger from the current context, if present. If one +// or more keys are provided, they will be resolved on the context and +// included in the logger. While context.Value takes an interface, any key +// argument passed to GetLogger will be passed to fmt.Sprint when expanded as +// a logging key field. If context keys are integer constants, for example, +// its recommended that a String method is implemented. +func GetLogger(ctx Context, keys ...interface{}) Logger { + return getLogrusLogger(ctx, keys...) +} + +// GetLogrusLogger returns the logrus logger for the context. If one more keys +// are provided, they will be resolved on the context and included in the +// logger. Only use this function if specific logrus functionality is +// required. +func getLogrusLogger(ctx Context, keys ...interface{}) *logrus.Entry { + var logger *logrus.Entry + + // Get a logger, if it is present. + loggerInterface := ctx.Value("logger") + if loggerInterface != nil { + if lgr, ok := loggerInterface.(*logrus.Entry); ok { + logger = lgr + } + } + + if logger == nil { + fields := logrus.Fields{} + + // Fill in the instance id, if we have it. + instanceID := ctx.Value("instance.id") + if instanceID != nil { + fields["instance.id"] = instanceID + } + + fields["go.version"] = runtime.Version() + // If no logger is found, just return the standard logger. + logger = logrus.StandardLogger().WithFields(fields) + } + + fields := logrus.Fields{} + for _, key := range keys { + v := ctx.Value(key) + if v != nil { + fields[fmt.Sprint(key)] = v + } + } + + return logger.WithFields(fields) +} diff --git a/vendor/github.com/docker/distribution/context/trace.go b/vendor/github.com/docker/distribution/context/trace.go new file mode 100644 index 000000000..721964a84 --- /dev/null +++ b/vendor/github.com/docker/distribution/context/trace.go @@ -0,0 +1,104 @@ +package context + +import ( + "runtime" + "time" + + "github.com/docker/distribution/uuid" +) + +// WithTrace allocates a traced timing span in a new context. This allows a +// caller to track the time between calling WithTrace and the returned done +// function. When the done function is called, a log message is emitted with a +// "trace.duration" field, corresponding to the elapsed time and a +// "trace.func" field, corresponding to the function that called WithTrace. +// +// The logging keys "trace.id" and "trace.parent.id" are provided to implement +// dapper-like tracing. This function should be complemented with a WithSpan +// method that could be used for tracing distributed RPC calls. +// +// The main benefit of this function is to post-process log messages or +// intercept them in a hook to provide timing data. Trace ids and parent ids +// can also be linked to provide call tracing, if so required. +// +// Here is an example of the usage: +// +// func timedOperation(ctx Context) { +// ctx, done := WithTrace(ctx) +// defer done("this will be the log message") +// // ... function body ... +// } +// +// If the function ran for roughly 1s, such a usage would emit a log message +// as follows: +// +// INFO[0001] this will be the log message trace.duration=1.004575763s trace.func=github.com/docker/distribution/context.traceOperation trace.id=<id> ... +// +// Notice that the function name is automatically resolved, along with the +// package and a trace id is emitted that can be linked with parent ids. +func WithTrace(ctx Context) (Context, func(format string, a ...interface{})) { + if ctx == nil { + ctx = Background() + } + + pc, file, line, _ := runtime.Caller(1) + f := runtime.FuncForPC(pc) + ctx = &traced{ + Context: ctx, + id: uuid.Generate().String(), + start: time.Now(), + parent: GetStringValue(ctx, "trace.id"), + fnname: f.Name(), + file: file, + line: line, + } + + return ctx, func(format string, a ...interface{}) { + GetLogger(ctx, + "trace.duration", + "trace.id", + "trace.parent.id", + "trace.func", + "trace.file", + "trace.line"). + Debugf(format, a...) + } +} + +// traced represents a context that is traced for function call timing. It +// also provides fast lookup for the various attributes that are available on +// the trace. +type traced struct { + Context + id string + parent string + start time.Time + fnname string + file string + line int +} + +func (ts *traced) Value(key interface{}) interface{} { + switch key { + case "trace.start": + return ts.start + case "trace.duration": + return time.Since(ts.start) + case "trace.id": + return ts.id + case "trace.parent.id": + if ts.parent == "" { + return nil // must return nil to signal no parent. + } + + return ts.parent + case "trace.func": + return ts.fnname + case "trace.file": + return ts.file + case "trace.line": + return ts.line + } + + return ts.Context.Value(key) +} diff --git a/vendor/github.com/docker/distribution/context/util.go b/vendor/github.com/docker/distribution/context/util.go new file mode 100644 index 000000000..cb9ef52e3 --- /dev/null +++ b/vendor/github.com/docker/distribution/context/util.go @@ -0,0 +1,24 @@ +package context + +import ( + "time" +) + +// Since looks up key, which should be a time.Time, and returns the duration +// since that time. If the key is not found, the value returned will be zero. +// This is helpful when inferring metrics related to context execution times. +func Since(ctx Context, key interface{}) time.Duration { + if startedAt, ok := ctx.Value(key).(time.Time); ok { + return time.Since(startedAt) + } + return 0 +} + +// GetStringValue returns a string value from the context. The empty string +// will be returned if not found. +func GetStringValue(ctx Context, key interface{}) (value string) { + if valuev, ok := ctx.Value(key).(string); ok { + value = valuev + } + return value +} diff --git a/vendor/github.com/docker/distribution/context/version.go b/vendor/github.com/docker/distribution/context/version.go new file mode 100644 index 000000000..746cda02e --- /dev/null +++ b/vendor/github.com/docker/distribution/context/version.go @@ -0,0 +1,16 @@ +package context + +// WithVersion stores the application version in the context. The new context +// gets a logger to ensure log messages are marked with the application +// version. +func WithVersion(ctx Context, version string) Context { + ctx = WithValue(ctx, "version", version) + // push a new logger onto the stack + return WithLogger(ctx, GetLogger(ctx, "version")) +} + +// GetVersion returns the application version from the context. An empty +// string may returned if the version was not set on the context. +func GetVersion(ctx Context) string { + return GetStringValue(ctx, "version") +} |