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path: root/vendor/google.golang.org/appengine/internal/api.go
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Diffstat (limited to 'vendor/google.golang.org/appengine/internal/api.go')
-rw-r--r--vendor/google.golang.org/appengine/internal/api.go678
1 files changed, 678 insertions, 0 deletions
diff --git a/vendor/google.golang.org/appengine/internal/api.go b/vendor/google.golang.org/appengine/internal/api.go
new file mode 100644
index 0000000..721053c
--- /dev/null
+++ b/vendor/google.golang.org/appengine/internal/api.go
@@ -0,0 +1,678 @@
+// Copyright 2011 Google Inc. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+// +build !appengine
+
+package internal
+
+import (
+ "bytes"
+ "errors"
+ "fmt"
+ "io/ioutil"
+ "log"
+ "net"
+ "net/http"
+ "net/url"
+ "os"
+ "runtime"
+ "strconv"
+ "strings"
+ "sync"
+ "sync/atomic"
+ "time"
+
+ "github.com/golang/protobuf/proto"
+ netcontext "golang.org/x/net/context"
+
+ basepb "google.golang.org/appengine/internal/base"
+ logpb "google.golang.org/appengine/internal/log"
+ remotepb "google.golang.org/appengine/internal/remote_api"
+)
+
+const (
+ apiPath = "/rpc_http"
+ defaultTicketSuffix = "/default.20150612t184001.0"
+)
+
+var (
+ // Incoming headers.
+ ticketHeader = http.CanonicalHeaderKey("X-AppEngine-API-Ticket")
+ dapperHeader = http.CanonicalHeaderKey("X-Google-DapperTraceInfo")
+ traceHeader = http.CanonicalHeaderKey("X-Cloud-Trace-Context")
+ curNamespaceHeader = http.CanonicalHeaderKey("X-AppEngine-Current-Namespace")
+ userIPHeader = http.CanonicalHeaderKey("X-AppEngine-User-IP")
+ remoteAddrHeader = http.CanonicalHeaderKey("X-AppEngine-Remote-Addr")
+ devRequestIdHeader = http.CanonicalHeaderKey("X-Appengine-Dev-Request-Id")
+
+ // Outgoing headers.
+ apiEndpointHeader = http.CanonicalHeaderKey("X-Google-RPC-Service-Endpoint")
+ apiEndpointHeaderValue = []string{"app-engine-apis"}
+ apiMethodHeader = http.CanonicalHeaderKey("X-Google-RPC-Service-Method")
+ apiMethodHeaderValue = []string{"/VMRemoteAPI.CallRemoteAPI"}
+ apiDeadlineHeader = http.CanonicalHeaderKey("X-Google-RPC-Service-Deadline")
+ apiContentType = http.CanonicalHeaderKey("Content-Type")
+ apiContentTypeValue = []string{"application/octet-stream"}
+ logFlushHeader = http.CanonicalHeaderKey("X-AppEngine-Log-Flush-Count")
+
+ apiHTTPClient = &http.Client{
+ Transport: &http.Transport{
+ Proxy: http.ProxyFromEnvironment,
+ Dial: limitDial,
+ MaxIdleConns: 1000,
+ MaxIdleConnsPerHost: 10000,
+ IdleConnTimeout: 90 * time.Second,
+ },
+ }
+
+ defaultTicketOnce sync.Once
+ defaultTicket string
+ backgroundContextOnce sync.Once
+ backgroundContext netcontext.Context
+)
+
+func apiURL() *url.URL {
+ host, port := "appengine.googleapis.internal", "10001"
+ if h := os.Getenv("API_HOST"); h != "" {
+ host = h
+ }
+ if p := os.Getenv("API_PORT"); p != "" {
+ port = p
+ }
+ return &url.URL{
+ Scheme: "http",
+ Host: host + ":" + port,
+ Path: apiPath,
+ }
+}
+
+func handleHTTP(w http.ResponseWriter, r *http.Request) {
+ c := &context{
+ req: r,
+ outHeader: w.Header(),
+ apiURL: apiURL(),
+ }
+ r = r.WithContext(withContext(r.Context(), c))
+ c.req = r
+
+ stopFlushing := make(chan int)
+
+ // Patch up RemoteAddr so it looks reasonable.
+ if addr := r.Header.Get(userIPHeader); addr != "" {
+ r.RemoteAddr = addr
+ } else if addr = r.Header.Get(remoteAddrHeader); addr != "" {
+ r.RemoteAddr = addr
+ } else {
+ // Should not normally reach here, but pick a sensible default anyway.
+ r.RemoteAddr = "127.0.0.1"
+ }
+ // The address in the headers will most likely be of these forms:
+ // 123.123.123.123
+ // 2001:db8::1
+ // net/http.Request.RemoteAddr is specified to be in "IP:port" form.
+ if _, _, err := net.SplitHostPort(r.RemoteAddr); err != nil {
+ // Assume the remote address is only a host; add a default port.
+ r.RemoteAddr = net.JoinHostPort(r.RemoteAddr, "80")
+ }
+
+ // Start goroutine responsible for flushing app logs.
+ // This is done after adding c to ctx.m (and stopped before removing it)
+ // because flushing logs requires making an API call.
+ go c.logFlusher(stopFlushing)
+
+ executeRequestSafely(c, r)
+ c.outHeader = nil // make sure header changes aren't respected any more
+
+ stopFlushing <- 1 // any logging beyond this point will be dropped
+
+ // Flush any pending logs asynchronously.
+ c.pendingLogs.Lock()
+ flushes := c.pendingLogs.flushes
+ if len(c.pendingLogs.lines) > 0 {
+ flushes++
+ }
+ c.pendingLogs.Unlock()
+ flushed := make(chan struct{})
+ go func() {
+ defer close(flushed)
+ // Force a log flush, because with very short requests we
+ // may not ever flush logs.
+ c.flushLog(true)
+ }()
+ w.Header().Set(logFlushHeader, strconv.Itoa(flushes))
+
+ // Avoid nil Write call if c.Write is never called.
+ if c.outCode != 0 {
+ w.WriteHeader(c.outCode)
+ }
+ if c.outBody != nil {
+ w.Write(c.outBody)
+ }
+ // Wait for the last flush to complete before returning,
+ // otherwise the security ticket will not be valid.
+ <-flushed
+}
+
+func executeRequestSafely(c *context, r *http.Request) {
+ defer func() {
+ if x := recover(); x != nil {
+ logf(c, 4, "%s", renderPanic(x)) // 4 == critical
+ c.outCode = 500
+ }
+ }()
+
+ http.DefaultServeMux.ServeHTTP(c, r)
+}
+
+func renderPanic(x interface{}) string {
+ buf := make([]byte, 16<<10) // 16 KB should be plenty
+ buf = buf[:runtime.Stack(buf, false)]
+
+ // Remove the first few stack frames:
+ // this func
+ // the recover closure in the caller
+ // That will root the stack trace at the site of the panic.
+ const (
+ skipStart = "internal.renderPanic"
+ skipFrames = 2
+ )
+ start := bytes.Index(buf, []byte(skipStart))
+ p := start
+ for i := 0; i < skipFrames*2 && p+1 < len(buf); i++ {
+ p = bytes.IndexByte(buf[p+1:], '\n') + p + 1
+ if p < 0 {
+ break
+ }
+ }
+ if p >= 0 {
+ // buf[start:p+1] is the block to remove.
+ // Copy buf[p+1:] over buf[start:] and shrink buf.
+ copy(buf[start:], buf[p+1:])
+ buf = buf[:len(buf)-(p+1-start)]
+ }
+
+ // Add panic heading.
+ head := fmt.Sprintf("panic: %v\n\n", x)
+ if len(head) > len(buf) {
+ // Extremely unlikely to happen.
+ return head
+ }
+ copy(buf[len(head):], buf)
+ copy(buf, head)
+
+ return string(buf)
+}
+
+// context represents the context of an in-flight HTTP request.
+// It implements the appengine.Context and http.ResponseWriter interfaces.
+type context struct {
+ req *http.Request
+
+ outCode int
+ outHeader http.Header
+ outBody []byte
+
+ pendingLogs struct {
+ sync.Mutex
+ lines []*logpb.UserAppLogLine
+ flushes int
+ }
+
+ apiURL *url.URL
+}
+
+var contextKey = "holds a *context"
+
+// jointContext joins two contexts in a superficial way.
+// It takes values and timeouts from a base context, and only values from another context.
+type jointContext struct {
+ base netcontext.Context
+ valuesOnly netcontext.Context
+}
+
+func (c jointContext) Deadline() (time.Time, bool) {
+ return c.base.Deadline()
+}
+
+func (c jointContext) Done() <-chan struct{} {
+ return c.base.Done()
+}
+
+func (c jointContext) Err() error {
+ return c.base.Err()
+}
+
+func (c jointContext) Value(key interface{}) interface{} {
+ if val := c.base.Value(key); val != nil {
+ return val
+ }
+ return c.valuesOnly.Value(key)
+}
+
+// fromContext returns the App Engine context or nil if ctx is not
+// derived from an App Engine context.
+func fromContext(ctx netcontext.Context) *context {
+ c, _ := ctx.Value(&contextKey).(*context)
+ return c
+}
+
+func withContext(parent netcontext.Context, c *context) netcontext.Context {
+ ctx := netcontext.WithValue(parent, &contextKey, c)
+ if ns := c.req.Header.Get(curNamespaceHeader); ns != "" {
+ ctx = withNamespace(ctx, ns)
+ }
+ return ctx
+}
+
+func toContext(c *context) netcontext.Context {
+ return withContext(netcontext.Background(), c)
+}
+
+func IncomingHeaders(ctx netcontext.Context) http.Header {
+ if c := fromContext(ctx); c != nil {
+ return c.req.Header
+ }
+ return nil
+}
+
+func ReqContext(req *http.Request) netcontext.Context {
+ return req.Context()
+}
+
+func WithContext(parent netcontext.Context, req *http.Request) netcontext.Context {
+ return jointContext{
+ base: parent,
+ valuesOnly: req.Context(),
+ }
+}
+
+// DefaultTicket returns a ticket used for background context or dev_appserver.
+func DefaultTicket() string {
+ defaultTicketOnce.Do(func() {
+ if IsDevAppServer() {
+ defaultTicket = "testapp" + defaultTicketSuffix
+ return
+ }
+ appID := partitionlessAppID()
+ escAppID := strings.Replace(strings.Replace(appID, ":", "_", -1), ".", "_", -1)
+ majVersion := VersionID(nil)
+ if i := strings.Index(majVersion, "."); i > 0 {
+ majVersion = majVersion[:i]
+ }
+ defaultTicket = fmt.Sprintf("%s/%s.%s.%s", escAppID, ModuleName(nil), majVersion, InstanceID())
+ })
+ return defaultTicket
+}
+
+func BackgroundContext() netcontext.Context {
+ backgroundContextOnce.Do(func() {
+ // Compute background security ticket.
+ ticket := DefaultTicket()
+
+ c := &context{
+ req: &http.Request{
+ Header: http.Header{
+ ticketHeader: []string{ticket},
+ },
+ },
+ apiURL: apiURL(),
+ }
+ backgroundContext = toContext(c)
+
+ // TODO(dsymonds): Wire up the shutdown handler to do a final flush.
+ go c.logFlusher(make(chan int))
+ })
+
+ return backgroundContext
+}
+
+// RegisterTestRequest registers the HTTP request req for testing, such that
+// any API calls are sent to the provided URL. It returns a closure to delete
+// the registration.
+// It should only be used by aetest package.
+func RegisterTestRequest(req *http.Request, apiURL *url.URL, decorate func(netcontext.Context) netcontext.Context) (*http.Request, func()) {
+ c := &context{
+ req: req,
+ apiURL: apiURL,
+ }
+ ctx := withContext(decorate(req.Context()), c)
+ req = req.WithContext(ctx)
+ c.req = req
+ return req, func() {}
+}
+
+var errTimeout = &CallError{
+ Detail: "Deadline exceeded",
+ Code: int32(remotepb.RpcError_CANCELLED),
+ Timeout: true,
+}
+
+func (c *context) Header() http.Header { return c.outHeader }
+
+// Copied from $GOROOT/src/pkg/net/http/transfer.go. Some response status
+// codes do not permit a response body (nor response entity headers such as
+// Content-Length, Content-Type, etc).
+func bodyAllowedForStatus(status int) bool {
+ switch {
+ case status >= 100 && status <= 199:
+ return false
+ case status == 204:
+ return false
+ case status == 304:
+ return false
+ }
+ return true
+}
+
+func (c *context) Write(b []byte) (int, error) {
+ if c.outCode == 0 {
+ c.WriteHeader(http.StatusOK)
+ }
+ if len(b) > 0 && !bodyAllowedForStatus(c.outCode) {
+ return 0, http.ErrBodyNotAllowed
+ }
+ c.outBody = append(c.outBody, b...)
+ return len(b), nil
+}
+
+func (c *context) WriteHeader(code int) {
+ if c.outCode != 0 {
+ logf(c, 3, "WriteHeader called multiple times on request.") // error level
+ return
+ }
+ c.outCode = code
+}
+
+func (c *context) post(body []byte, timeout time.Duration) (b []byte, err error) {
+ hreq := &http.Request{
+ Method: "POST",
+ URL: c.apiURL,
+ Header: http.Header{
+ apiEndpointHeader: apiEndpointHeaderValue,
+ apiMethodHeader: apiMethodHeaderValue,
+ apiContentType: apiContentTypeValue,
+ apiDeadlineHeader: []string{strconv.FormatFloat(timeout.Seconds(), 'f', -1, 64)},
+ },
+ Body: ioutil.NopCloser(bytes.NewReader(body)),
+ ContentLength: int64(len(body)),
+ Host: c.apiURL.Host,
+ }
+ if info := c.req.Header.Get(dapperHeader); info != "" {
+ hreq.Header.Set(dapperHeader, info)
+ }
+ if info := c.req.Header.Get(traceHeader); info != "" {
+ hreq.Header.Set(traceHeader, info)
+ }
+
+ tr := apiHTTPClient.Transport.(*http.Transport)
+
+ var timedOut int32 // atomic; set to 1 if timed out
+ t := time.AfterFunc(timeout, func() {
+ atomic.StoreInt32(&timedOut, 1)
+ tr.CancelRequest(hreq)
+ })
+ defer t.Stop()
+ defer func() {
+ // Check if timeout was exceeded.
+ if atomic.LoadInt32(&timedOut) != 0 {
+ err = errTimeout
+ }
+ }()
+
+ hresp, err := apiHTTPClient.Do(hreq)
+ if err != nil {
+ return nil, &CallError{
+ Detail: fmt.Sprintf("service bridge HTTP failed: %v", err),
+ Code: int32(remotepb.RpcError_UNKNOWN),
+ }
+ }
+ defer hresp.Body.Close()
+ hrespBody, err := ioutil.ReadAll(hresp.Body)
+ if hresp.StatusCode != 200 {
+ return nil, &CallError{
+ Detail: fmt.Sprintf("service bridge returned HTTP %d (%q)", hresp.StatusCode, hrespBody),
+ Code: int32(remotepb.RpcError_UNKNOWN),
+ }
+ }
+ if err != nil {
+ return nil, &CallError{
+ Detail: fmt.Sprintf("service bridge response bad: %v", err),
+ Code: int32(remotepb.RpcError_UNKNOWN),
+ }
+ }
+ return hrespBody, nil
+}
+
+func Call(ctx netcontext.Context, service, method string, in, out proto.Message) error {
+ if ns := NamespaceFromContext(ctx); ns != "" {
+ if fn, ok := NamespaceMods[service]; ok {
+ fn(in, ns)
+ }
+ }
+
+ if f, ctx, ok := callOverrideFromContext(ctx); ok {
+ return f(ctx, service, method, in, out)
+ }
+
+ // Handle already-done contexts quickly.
+ select {
+ case <-ctx.Done():
+ return ctx.Err()
+ default:
+ }
+
+ c := fromContext(ctx)
+ if c == nil {
+ // Give a good error message rather than a panic lower down.
+ return errNotAppEngineContext
+ }
+
+ // Apply transaction modifications if we're in a transaction.
+ if t := transactionFromContext(ctx); t != nil {
+ if t.finished {
+ return errors.New("transaction context has expired")
+ }
+ applyTransaction(in, &t.transaction)
+ }
+
+ // Default RPC timeout is 60s.
+ timeout := 60 * time.Second
+ if deadline, ok := ctx.Deadline(); ok {
+ timeout = deadline.Sub(time.Now())
+ }
+
+ data, err := proto.Marshal(in)
+ if err != nil {
+ return err
+ }
+
+ ticket := c.req.Header.Get(ticketHeader)
+ // Use a test ticket under test environment.
+ if ticket == "" {
+ if appid := ctx.Value(&appIDOverrideKey); appid != nil {
+ ticket = appid.(string) + defaultTicketSuffix
+ }
+ }
+ // Fall back to use background ticket when the request ticket is not available in Flex or dev_appserver.
+ if ticket == "" {
+ ticket = DefaultTicket()
+ }
+ if dri := c.req.Header.Get(devRequestIdHeader); IsDevAppServer() && dri != "" {
+ ticket = dri
+ }
+ req := &remotepb.Request{
+ ServiceName: &service,
+ Method: &method,
+ Request: data,
+ RequestId: &ticket,
+ }
+ hreqBody, err := proto.Marshal(req)
+ if err != nil {
+ return err
+ }
+
+ hrespBody, err := c.post(hreqBody, timeout)
+ if err != nil {
+ return err
+ }
+
+ res := &remotepb.Response{}
+ if err := proto.Unmarshal(hrespBody, res); err != nil {
+ return err
+ }
+ if res.RpcError != nil {
+ ce := &CallError{
+ Detail: res.RpcError.GetDetail(),
+ Code: *res.RpcError.Code,
+ }
+ switch remotepb.RpcError_ErrorCode(ce.Code) {
+ case remotepb.RpcError_CANCELLED, remotepb.RpcError_DEADLINE_EXCEEDED:
+ ce.Timeout = true
+ }
+ return ce
+ }
+ if res.ApplicationError != nil {
+ return &APIError{
+ Service: *req.ServiceName,
+ Detail: res.ApplicationError.GetDetail(),
+ Code: *res.ApplicationError.Code,
+ }
+ }
+ if res.Exception != nil || res.JavaException != nil {
+ // This shouldn't happen, but let's be defensive.
+ return &CallError{
+ Detail: "service bridge returned exception",
+ Code: int32(remotepb.RpcError_UNKNOWN),
+ }
+ }
+ return proto.Unmarshal(res.Response, out)
+}
+
+func (c *context) Request() *http.Request {
+ return c.req
+}
+
+func (c *context) addLogLine(ll *logpb.UserAppLogLine) {
+ // Truncate long log lines.
+ // TODO(dsymonds): Check if this is still necessary.
+ const lim = 8 << 10
+ if len(*ll.Message) > lim {
+ suffix := fmt.Sprintf("...(length %d)", len(*ll.Message))
+ ll.Message = proto.String((*ll.Message)[:lim-len(suffix)] + suffix)
+ }
+
+ c.pendingLogs.Lock()
+ c.pendingLogs.lines = append(c.pendingLogs.lines, ll)
+ c.pendingLogs.Unlock()
+}
+
+var logLevelName = map[int64]string{
+ 0: "DEBUG",
+ 1: "INFO",
+ 2: "WARNING",
+ 3: "ERROR",
+ 4: "CRITICAL",
+}
+
+func logf(c *context, level int64, format string, args ...interface{}) {
+ if c == nil {
+ panic("not an App Engine context")
+ }
+ s := fmt.Sprintf(format, args...)
+ s = strings.TrimRight(s, "\n") // Remove any trailing newline characters.
+ c.addLogLine(&logpb.UserAppLogLine{
+ TimestampUsec: proto.Int64(time.Now().UnixNano() / 1e3),
+ Level: &level,
+ Message: &s,
+ })
+ // Only duplicate log to stderr if not running on App Engine second generation
+ if !IsSecondGen() {
+ log.Print(logLevelName[level] + ": " + s)
+ }
+}
+
+// flushLog attempts to flush any pending logs to the appserver.
+// It should not be called concurrently.
+func (c *context) flushLog(force bool) (flushed bool) {
+ c.pendingLogs.Lock()
+ // Grab up to 30 MB. We can get away with up to 32 MB, but let's be cautious.
+ n, rem := 0, 30<<20
+ for ; n < len(c.pendingLogs.lines); n++ {
+ ll := c.pendingLogs.lines[n]
+ // Each log line will require about 3 bytes of overhead.
+ nb := proto.Size(ll) + 3
+ if nb > rem {
+ break
+ }
+ rem -= nb
+ }
+ lines := c.pendingLogs.lines[:n]
+ c.pendingLogs.lines = c.pendingLogs.lines[n:]
+ c.pendingLogs.Unlock()
+
+ if len(lines) == 0 && !force {
+ // Nothing to flush.
+ return false
+ }
+
+ rescueLogs := false
+ defer func() {
+ if rescueLogs {
+ c.pendingLogs.Lock()
+ c.pendingLogs.lines = append(lines, c.pendingLogs.lines...)
+ c.pendingLogs.Unlock()
+ }
+ }()
+
+ buf, err := proto.Marshal(&logpb.UserAppLogGroup{
+ LogLine: lines,
+ })
+ if err != nil {
+ log.Printf("internal.flushLog: marshaling UserAppLogGroup: %v", err)
+ rescueLogs = true
+ return false
+ }
+
+ req := &logpb.FlushRequest{
+ Logs: buf,
+ }
+ res := &basepb.VoidProto{}
+ c.pendingLogs.Lock()
+ c.pendingLogs.flushes++
+ c.pendingLogs.Unlock()
+ if err := Call(toContext(c), "logservice", "Flush", req, res); err != nil {
+ log.Printf("internal.flushLog: Flush RPC: %v", err)
+ rescueLogs = true
+ return false
+ }
+ return true
+}
+
+const (
+ // Log flushing parameters.
+ flushInterval = 1 * time.Second
+ forceFlushInterval = 60 * time.Second
+)
+
+func (c *context) logFlusher(stop <-chan int) {
+ lastFlush := time.Now()
+ tick := time.NewTicker(flushInterval)
+ for {
+ select {
+ case <-stop:
+ // Request finished.
+ tick.Stop()
+ return
+ case <-tick.C:
+ force := time.Now().Sub(lastFlush) > forceFlushInterval
+ if c.flushLog(force) {
+ lastFlush = time.Now()
+ }
+ }
+ }
+}
+
+func ContextForTesting(req *http.Request) netcontext.Context {
+ return toContext(&context{req: req})
+}