restic/vendor/cloud.google.com/go/errorreporting/errors.go

457 lines
13 KiB
Go
Raw Normal View History

2017-09-13 12:09:48 +00:00
// Copyright 2016 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package errorreporting is a Google Stackdriver Error Reporting library.
//
// This package is still experimental and subject to change.
//
// See https://cloud.google.com/error-reporting/ for more information.
//
// To initialize a client, use the NewClient function.
//
// import "cloud.google.com/go/errorreporting"
// ...
// errorsClient, err = errorreporting.NewClient(ctx, projectID, "myservice", "v1.0", true)
//
// The client can recover panics in your program and report them as errors.
// To use this functionality, defer its Catch method, as you would any other
// function for recovering panics.
//
// func foo(ctx context.Context, ...) {
// defer errorsClient.Catch(ctx)
// ...
// }
//
// Catch writes an error report containing the recovered value and a stack trace
// to Stackdriver Error Reporting.
//
// There are various options you can add to the call to Catch that modify how
// panics are handled.
//
// WithMessage and WithMessagef add a custom message after the recovered value,
// using fmt.Sprint and fmt.Sprintf respectively.
//
// defer errorsClient.Catch(ctx, errorreporting.WithMessagef("x=%d", x))
//
// WithRequest fills in various fields in the error report with information
// about an http.Request that's being handled.
//
// defer errorsClient.Catch(ctx, errorreporting.WithRequest(httpReq))
//
// By default, after recovering a panic, Catch will panic again with the
// recovered value. You can turn off this behavior with the Repanic option.
//
// defer errorsClient.Catch(ctx, errorreporting.Repanic(false))
//
// You can also change the default behavior for the client by changing the
// RepanicDefault field.
//
// errorsClient.RepanicDefault = false
//
// It is also possible to write an error report directly without recovering a
// panic, using Report or Reportf.
//
// if err != nil {
// errorsClient.Reportf(ctx, r, "unexpected error %v", err)
// }
//
// If you try to write an error report with a nil client, or if the client
// fails to write the report to the server, the error report is logged using
// log.Println.
package errorreporting // import "cloud.google.com/go/errorreporting"
import (
"bytes"
"fmt"
"log"
"net/http"
"runtime"
"strings"
"time"
api "cloud.google.com/go/errorreporting/apiv1beta1"
"cloud.google.com/go/internal/version"
"cloud.google.com/go/logging"
"github.com/golang/protobuf/ptypes/timestamp"
gax "github.com/googleapis/gax-go"
"golang.org/x/net/context"
"google.golang.org/api/option"
erpb "google.golang.org/genproto/googleapis/devtools/clouderrorreporting/v1beta1"
)
const (
userAgent = `gcloud-golang-errorreporting/20160701`
)
type apiInterface interface {
ReportErrorEvent(ctx context.Context, req *erpb.ReportErrorEventRequest, opts ...gax.CallOption) (*erpb.ReportErrorEventResponse, error)
Close() error
}
var newApiInterface = func(ctx context.Context, opts ...option.ClientOption) (apiInterface, error) {
client, err := api.NewReportErrorsClient(ctx, opts...)
if err != nil {
return nil, err
}
client.SetGoogleClientInfo("gccl", version.Repo)
return client, nil
}
type loggerInterface interface {
LogSync(ctx context.Context, e logging.Entry) error
Close() error
}
type logger struct {
*logging.Logger
c *logging.Client
}
func (l logger) Close() error {
return l.c.Close()
}
var newLoggerInterface = func(ctx context.Context, projectID string, opts ...option.ClientOption) (loggerInterface, error) {
lc, err := logging.NewClient(ctx, projectID, opts...)
if err != nil {
return nil, fmt.Errorf("creating Logging client: %v", err)
}
l := lc.Logger("errorreports")
return logger{l, lc}, nil
}
type sender interface {
send(ctx context.Context, r *http.Request, message string)
close() error
}
// errorApiSender sends error reports using the Stackdriver Error Reporting API.
type errorApiSender struct {
apiClient apiInterface
projectID string
serviceContext erpb.ServiceContext
}
// loggingSender sends error reports using the Stackdriver Logging API.
type loggingSender struct {
logger loggerInterface
projectID string
serviceContext map[string]string
}
// Client represents a Google Cloud Error Reporting client.
type Client struct {
sender
// RepanicDefault determines whether Catch will re-panic after recovering a
// panic. This behavior can be overridden for an individual call to Catch using
// the Repanic option.
RepanicDefault bool
}
// NewClient returns a new error reporting client. Generally you will want
// to create a client on program initialization and use it through the lifetime
// of the process.
//
// The service name and version string identify the running program, and are
// included in error reports. The version string can be left empty.
//
// Set useLogging to report errors also using Stackdriver Logging,
// which will result in errors appearing in both the logs and the error
// dashboard. This is useful if you are already a user of Stackdriver Logging.
func NewClient(ctx context.Context, projectID, serviceName, serviceVersion string, useLogging bool, opts ...option.ClientOption) (*Client, error) {
if useLogging {
l, err := newLoggerInterface(ctx, projectID, opts...)
if err != nil {
return nil, fmt.Errorf("creating Logging client: %v", err)
}
sender := &loggingSender{
logger: l,
projectID: projectID,
serviceContext: map[string]string{
"service": serviceName,
},
}
if serviceVersion != "" {
sender.serviceContext["version"] = serviceVersion
}
c := &Client{
sender: sender,
RepanicDefault: true,
}
return c, nil
} else {
a, err := newApiInterface(ctx, opts...)
if err != nil {
return nil, fmt.Errorf("creating Error Reporting client: %v", err)
}
c := &Client{
sender: &errorApiSender{
apiClient: a,
projectID: "projects/" + projectID,
serviceContext: erpb.ServiceContext{
Service: serviceName,
Version: serviceVersion,
},
},
RepanicDefault: true,
}
return c, nil
}
}
// Close closes any resources held by the client.
// Close should be called when the client is no longer needed.
// It need not be called at program exit.
func (c *Client) Close() error {
err := c.sender.close()
c.sender = nil
return err
}
// An Option is an optional argument to Catch.
type Option interface {
isOption()
}
// PanicFlag returns an Option that can inform Catch that a panic has occurred.
// If *p is true when Catch is called, an error report is made even if recover
// returns nil. This allows Catch to report an error for panic(nil).
// If p is nil, the option is ignored.
//
// Here is an example of how to use PanicFlag:
//
// func foo(ctx context.Context, ...) {
// hasPanicked := true
// defer errorsClient.Catch(ctx, errorreporting.PanicFlag(&hasPanicked))
// ...
// ...
// // We have reached the end of the function, so we're not panicking.
// hasPanicked = false
// }
func PanicFlag(p *bool) Option { return panicFlag{p} }
type panicFlag struct {
*bool
}
func (h panicFlag) isOption() {}
// Repanic returns an Option that determines whether Catch will re-panic after
// it reports an error. This overrides the default in the client.
func Repanic(r bool) Option { return repanic(r) }
type repanic bool
func (r repanic) isOption() {}
// WithRequest returns an Option that informs Catch or Report of an http.Request
// that is being handled. Information from the Request is included in the error
// report, if one is made.
func WithRequest(r *http.Request) Option { return withRequest{r} }
type withRequest struct {
*http.Request
}
func (w withRequest) isOption() {}
// WithMessage returns an Option that sets a message to be included in the error
// report, if one is made. v is converted to a string with fmt.Sprint.
func WithMessage(v ...interface{}) Option { return message(v) }
type message []interface{}
func (m message) isOption() {}
// WithMessagef returns an Option that sets a message to be included in the error
// report, if one is made. format and v are converted to a string with fmt.Sprintf.
func WithMessagef(format string, v ...interface{}) Option { return messagef{format, v} }
type messagef struct {
format string
v []interface{}
}
func (m messagef) isOption() {}
// Catch tries to recover a panic; if it succeeds, it writes an error report.
// It should be called by deferring it, like any other function for recovering
// panics.
//
// Catch can be called concurrently with other calls to Catch, Report or Reportf.
func (c *Client) Catch(ctx context.Context, opt ...Option) {
panicked := false
for _, o := range opt {
switch o := o.(type) {
case panicFlag:
panicked = panicked || o.bool != nil && *o.bool
}
}
x := recover()
if x == nil && !panicked {
return
}
var (
r *http.Request
shouldRepanic = true
messages = []string{fmt.Sprint(x)}
)
if c != nil {
shouldRepanic = c.RepanicDefault
}
for _, o := range opt {
switch o := o.(type) {
case repanic:
shouldRepanic = bool(o)
case withRequest:
r = o.Request
case message:
messages = append(messages, fmt.Sprint(o...))
case messagef:
messages = append(messages, fmt.Sprintf(o.format, o.v...))
}
}
c.logInternal(ctx, r, true, strings.Join(messages, " "))
if shouldRepanic {
panic(x)
}
}
// Report writes an error report unconditionally, instead of only when a panic
// occurs.
// If r is non-nil, information from the Request is included in the error report.
//
// Report can be called concurrently with other calls to Catch, Report or Reportf.
func (c *Client) Report(ctx context.Context, r *http.Request, v ...interface{}) {
c.logInternal(ctx, r, false, fmt.Sprint(v...))
}
// Reportf writes an error report unconditionally, instead of only when a panic
// occurs.
// If r is non-nil, information from the Request is included in the error report.
//
// Reportf can be called concurrently with other calls to Catch, Report or Reportf.
func (c *Client) Reportf(ctx context.Context, r *http.Request, format string, v ...interface{}) {
c.logInternal(ctx, r, false, fmt.Sprintf(format, v...))
}
func (c *Client) logInternal(ctx context.Context, r *http.Request, isPanic bool, msg string) {
// limit the stack trace to 16k.
var buf [16384]byte
stack := buf[0:runtime.Stack(buf[:], false)]
message := msg + "\n" + chopStack(stack, isPanic)
if c == nil {
log.Println("Error report used nil client:", message)
return
}
c.send(ctx, r, message)
}
func (s *loggingSender) send(ctx context.Context, r *http.Request, message string) {
payload := map[string]interface{}{
"eventTime": time.Now().In(time.UTC).Format(time.RFC3339Nano),
"message": message,
"serviceContext": s.serviceContext,
}
if r != nil {
payload["context"] = map[string]interface{}{
"httpRequest": map[string]interface{}{
"method": r.Method,
"url": r.Host + r.RequestURI,
"userAgent": r.UserAgent(),
"referrer": r.Referer(),
"remoteIp": r.RemoteAddr,
},
}
}
e := logging.Entry{
Severity: logging.Error,
Payload: payload,
}
err := s.logger.LogSync(ctx, e)
if err != nil {
log.Println("Error writing error report:", err, "report:", payload)
}
}
func (s *loggingSender) close() error {
return s.logger.Close()
}
func (s *errorApiSender) send(ctx context.Context, r *http.Request, message string) {
time := time.Now()
var errorContext *erpb.ErrorContext
if r != nil {
errorContext = &erpb.ErrorContext{
HttpRequest: &erpb.HttpRequestContext{
Method: r.Method,
Url: r.Host + r.RequestURI,
UserAgent: r.UserAgent(),
Referrer: r.Referer(),
RemoteIp: r.RemoteAddr,
},
}
}
req := erpb.ReportErrorEventRequest{
ProjectName: s.projectID,
Event: &erpb.ReportedErrorEvent{
EventTime: &timestamp.Timestamp{
Seconds: time.Unix(),
Nanos: int32(time.Nanosecond()),
},
ServiceContext: &s.serviceContext,
Message: message,
Context: errorContext,
},
}
_, err := s.apiClient.ReportErrorEvent(ctx, &req)
if err != nil {
log.Println("Error writing error report:", err, "report:", message)
}
}
func (s *errorApiSender) close() error {
return s.apiClient.Close()
}
// chopStack trims a stack trace so that the function which panics or calls
// Report is first.
func chopStack(s []byte, isPanic bool) string {
var f []byte
if isPanic {
f = []byte("panic(")
} else {
f = []byte("cloud.google.com/go/errorreporting.(*Client).Report")
}
lfFirst := bytes.IndexByte(s, '\n')
if lfFirst == -1 {
return string(s)
}
stack := s[lfFirst:]
panicLine := bytes.Index(stack, f)
if panicLine == -1 {
return string(s)
}
stack = stack[panicLine+1:]
for i := 0; i < 2; i++ {
nextLine := bytes.IndexByte(stack, '\n')
if nextLine == -1 {
return string(s)
}
stack = stack[nextLine+1:]
}
return string(s[:lfFirst+1]) + string(stack)
}