Merge pull request #310 from jlhawn/improve_context_pkg

context: improve context package
This commit is contained in:
Stephen Day 2015-04-01 16:39:59 -07:00
commit da9d49d186
9 changed files with 97 additions and 63 deletions

4
.gitignore vendored
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@ -31,3 +31,7 @@ bin/*
# Cover profiles
*.out
# Editor/IDE specific files.
*.sublime-project
*.sublime-workspace

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@ -224,7 +224,7 @@ func configureLogging(ctx context.Context, config *configuration.Configuration)
fields = append(fields, k)
}
ctx = withMapContext(ctx, config.Log.Fields)
ctx = ctxu.WithValues(ctx, config.Log.Fields)
ctx = ctxu.WithLogger(ctx, ctxu.GetLogger(ctx, fields...))
}
@ -241,36 +241,6 @@ func logLevel(level configuration.Loglevel) log.Level {
return l
}
// 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]string
}
// withMapContext returns a context that proxies lookups through a map.
func withMapContext(ctx context.Context, m map[string]string) context.Context {
mo := make(map[string]string, 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)
}
// debugServer starts the debug server with pprof, expvar among other
// endpoints. The addr should not be exposed externally. For most of these to
// work, tls cannot be enabled on the endpoint, so it is generally separate.

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@ -28,7 +28,7 @@ type Configuration struct {
// Fields allows users to specify static string fields to include in
// the logger context.
Fields map[string]string `yaml:"fields"`
Fields map[string]interface{} `yaml:"fields"`
}
// Loglevel is the level at which registry operations are logged. This is

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@ -17,11 +17,11 @@ func Test(t *testing.T) { TestingT(t) }
var configStruct = Configuration{
Version: "0.1",
Log: struct {
Level Loglevel `yaml:"level"`
Formatter string `yaml:"formatter"`
Fields map[string]string `yaml:"fields"`
Level Loglevel `yaml:"level"`
Formatter string `yaml:"formatter"`
Fields map[string]interface{} `yaml:"fields"`
}{
Fields: map[string]string{"environment": "test"},
Fields: map[string]interface{}{"environment": "test"},
},
Loglevel: "info",
Storage: Storage{
@ -340,7 +340,7 @@ func copyConfig(config Configuration) *Configuration {
configCopy.Version = MajorMinorVersion(config.Version.Major(), config.Version.Minor())
configCopy.Loglevel = config.Loglevel
configCopy.Log = config.Log
configCopy.Log.Fields = make(map[string]string, len(config.Log.Fields))
configCopy.Log.Fields = make(map[string]interface{}, len(config.Log.Fields))
for k, v := range config.Log.Fields {
configCopy.Log.Fields[k] = v
}

53
context/context.go Normal file
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@ -0,0 +1,53 @@
package context
import (
"golang.org/x/net/context"
)
// Context is a copy of Context from the golang.org/x/net/context package.
type Context interface {
context.Context
}
// Background returns a non-nil, empty Context.
func Background() Context {
return context.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)
}

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@ -11,7 +11,6 @@ import (
"code.google.com/p/go-uuid/uuid"
log "github.com/Sirupsen/logrus"
"github.com/gorilla/mux"
"golang.org/x/net/context"
)
// Common errors used with this package.
@ -50,12 +49,25 @@ func RemoteAddr(r *http.Request) string {
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.Context, r *http.Request) context.Context {
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
@ -74,7 +86,7 @@ func WithRequest(ctx context.Context, r *http.Request) context.Context {
// 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.Context) (*http.Request, error) {
func GetRequest(ctx Context) (*http.Request, error) {
if r, ok := ctx.Value("http.request").(*http.Request); r != nil && ok {
return r, nil
}
@ -83,13 +95,13 @@ func GetRequest(ctx context.Context) (*http.Request, error) {
// 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.Context) string {
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.Context, w http.ResponseWriter) (context.Context, http.ResponseWriter) {
func WithResponseWriter(ctx Context, w http.ResponseWriter) (Context, http.ResponseWriter) {
irw := &instrumentedResponseWriter{
ResponseWriter: w,
Context: ctx,
@ -107,7 +119,7 @@ var getVarsFromRequest = mux.Vars
// 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.Context, r *http.Request) context.Context {
func WithVars(ctx Context, r *http.Request) Context {
return &muxVarsContext{
Context: ctx,
vars: getVarsFromRequest(r),
@ -117,7 +129,7 @@ func WithVars(ctx context.Context, r *http.Request) context.Context {
// 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.Context) Logger {
func GetRequestLogger(ctx Context) Logger {
return GetLogger(ctx,
"http.request.id",
"http.request.method",
@ -133,7 +145,7 @@ func GetRequestLogger(ctx context.Context) 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.Context) Logger {
func GetResponseLogger(ctx Context) Logger {
l := getLogrusLogger(ctx,
"http.response.written",
"http.response.status",
@ -142,7 +154,7 @@ func GetResponseLogger(ctx context.Context) Logger {
duration := Since(ctx, "http.request.startedat")
if duration > 0 {
l = l.WithField("http.response.duration", duration)
l = l.WithField("http.response.duration", duration.String())
}
return l
@ -150,7 +162,7 @@ func GetResponseLogger(ctx context.Context) Logger {
// httpRequestContext makes information about a request available to context.
type httpRequestContext struct {
context.Context
Context
startedAt time.Time
id string
@ -209,7 +221,7 @@ fallback:
}
type muxVarsContext struct {
context.Context
Context
vars map[string]string
}
@ -235,7 +247,7 @@ func (ctx *muxVarsContext) Value(key interface{}) interface{} {
// context.
type instrumentedResponseWriter struct {
http.ResponseWriter
context.Context
Context
mu sync.Mutex
status int

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@ -8,8 +8,6 @@ import (
"reflect"
"testing"
"time"
"golang.org/x/net/context"
)
func TestWithRequest(t *testing.T) {
@ -23,7 +21,7 @@ func TestWithRequest(t *testing.T) {
req.Header.Set("Referer", "foo.com/referer")
req.Header.Set("User-Agent", "test/0.1")
ctx := WithRequest(context.Background(), &req)
ctx := WithRequest(Background(), &req)
for _, testcase := range []struct {
key string
expected interface{}
@ -132,7 +130,7 @@ func (trw *testResponseWriter) Flush() {
func TestWithResponseWriter(t *testing.T) {
trw := testResponseWriter{}
ctx, rw := WithResponseWriter(context.Background(), &trw)
ctx, rw := WithResponseWriter(Background(), &trw)
if ctx.Value("http.response") != &trw {
t.Fatalf("response not available in context: %v != %v", ctx.Value("http.response"), &trw)
@ -183,7 +181,7 @@ func TestWithVars(t *testing.T) {
return vars
}
ctx := WithVars(context.Background(), &req)
ctx := WithVars(Background(), &req)
for _, testcase := range []struct {
key string
expected interface{}

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@ -4,7 +4,6 @@ import (
"fmt"
"github.com/Sirupsen/logrus"
"golang.org/x/net/context"
)
// Logger provides a leveled-logging interface.
@ -41,8 +40,8 @@ type Logger interface {
}
// WithLogger creates a new context with provided logger.
func WithLogger(ctx context.Context, logger Logger) context.Context {
return context.WithValue(ctx, "logger", logger)
func WithLogger(ctx Context, logger Logger) Context {
return WithValue(ctx, "logger", logger)
}
// GetLogger returns the logger from the current context, if present. If one
@ -51,7 +50,7 @@ func WithLogger(ctx context.Context, logger Logger) context.Context {
// 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.Context, keys ...interface{}) Logger {
func GetLogger(ctx Context, keys ...interface{}) Logger {
return getLogrusLogger(ctx, keys...)
}
@ -59,7 +58,7 @@ func GetLogger(ctx context.Context, keys ...interface{}) Logger {
// 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.Context, keys ...interface{}) *logrus.Entry {
func getLogrusLogger(ctx Context, keys ...interface{}) *logrus.Entry {
var logger *logrus.Entry
// Get a logger, if it is present.

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@ -2,14 +2,12 @@ package context
import (
"time"
"golang.org/x/net/context"
)
// 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.Context, key interface{}) time.Duration {
func Since(ctx Context, key interface{}) time.Duration {
startedAtI := ctx.Value(key)
if startedAtI != nil {
if startedAt, ok := startedAtI.(time.Time); ok {
@ -22,7 +20,7 @@ func Since(ctx context.Context, key interface{}) time.Duration {
// GetStringValue returns a string value from the context. The empty string
// will be returned if not found.
func GetStringValue(ctx context.Context, key string) (value string) {
func GetStringValue(ctx Context, key string) (value string) {
stringi := ctx.Value(key)
if stringi != nil {
if valuev, ok := stringi.(string); ok {