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Support setting depth to structured logging 

Signed-off-by: JunYang <yang.jun22@zte.com.cn>
This commit is contained in:
JunYang 2021-05-30 20:46:20 +08:00
parent fc4656b934
commit 25ca9642c9
1 changed files with 16 additions and 40 deletions
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56
contributors/devel/sig-instrumentation/migration-to-structured-logging.md
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@ -40,6 +40,10 @@ package klog
// >> I1025 00:15:15.525108 1 controller_utils.go:116] "Pod status updated" pod="kube-system/kubedns" status="ready"
func InfoS(msg string, keysAndValues ...interface{})
// InfoSDepth acts as InfoS but uses depth to determine which call frame to log.
// InfoSDepth(0, "msg") is the same as InfoS("msg").
func InfoSDepth(depth int, msg string, keysAndValues ...interface{})
// ErrorS structured logs to the ERROR, WARNING, and INFO logs.
// the err argument used as "err" field of log line.
// The msg argument used to add constant description to the log line.
@ -51,6 +55,10 @@ func InfoS(msg string, keysAndValues ...interface{})
// >> E1025 00:15:15.525108 1 controller_utils.go:114] "Failed to update pod status" err="timeout"
func ErrorS(err error, msg string, keysAndValues ...interface{})
// ErrorSDepth acts as ErrorS but uses depth to determine which call frame to log.
// ErrorSDepth(0, "msg") is the same as ErrorS("msg").
func ErrorSDepth(depth int, err error, msg string, keysAndValues ...interface{})
// KObj is used to create ObjectRef when logging information about Kubernetes objects
// Examples:
// >> klog.InfoS("Pod status updated", "pod", klog.KObj(pod), "status", "ready")
@ -95,50 +103,18 @@ Structured logging functions follow a different logging interface design than ot
minimal design from [logr] thus there is no one-to-one mapping.
Simplified mapping between functions:
* `klog.Infof`, `klog.Info`, `klog.Infoln`, `klog.InfoDepth` -> `klog.InfoS`
* `klog.Infof`, `klog.Info`, `klog.Infoln` -> `klog.InfoS`
* `klog.InfoDepth` -> `klog.InfoSDepth`
* `klog.V(N).Infof`, `klog.V(N).Info`, `klog.V(N).Infoln` -> `klog.V(N).InfoS`
* `klog.Warning`, `klog.Warningf`, `klog.Warningln`, `klog.WarningDepth` -> `klog.InfoS`
* `klog.V(N).Warning`, `klog.V(N).Warningf`, `klog.V(N).Warningln`, `klog.V(N).WarningDepth` -> `klog.V(N).InfoS`
* `klog.Error`, `klog.Errorf`, `klog.Errorln`, `klog.ErrorDepth` -> `klog.ErrorS`
* `klog.V(N).Error`, `klog.V(N).Errorf`, `klog.V(N).Errorln`, `klog.V(N).ErrorDepth` -> `klog.ErrorS`
* `klog.Fatal`, `klog.Fatalf`, `klog.Fatalln`, `klog.FatalDepth` -> `klog.ErrorS` followed by `os.Exit(1)` ([see below])
* `klog.V(N).Fatal`, `klog.V(N).Fatalf`, `klog.V(N).Fatalln`, `klog.V(N).FatalDepth` -> `klog.ErrorS` followed by `os.Exit(1)` ([see below])
* `klog.Warning`, `klog.Warningf`, `klog.Warningln` -> `klog.InfoS`
* `klog.WarningDepth` -> `klog.InfoSDepth`
* `klog.Error`, `klog.Errorf`, `klog.Errorln` -> `klog.ErrorS`
* `klog.ErrorDepth` -> `klog.ErrorSDepth`
* `klog.Fatal`, `klog.Fatalf`, `klog.Fatalln` -> `klog.ErrorS` followed by `os.Exit(1)` ([see below])
* `klog.FatalDepth` -> `klog.ErrorDepth` followed by `os.Exit(1)` ([see below])
[see below]: #replacing-fatal-calls
### Removing Depth
Functions with depth (`klog.InfoDepth`, `klog.WarningDepth`, `klog.ErrorDepth`, `klog.FatalDepth`) are used to indicate
that the source of the log (added as metadata in log) is different than the invocation of logging library. This is
usually used when implementing logging util functions. As logr interface doesn't support depth, those functions should
return logging arguments instead of calling `klog` directly.
For example
```go
func Handle(w http.ReponseWriter, r *http.Request) {
logHTTPRequest(r)
handle(w, r)
}
func logHTTPRequest(r *http.Request) {
klog.InfoDepth(1, "Received HTTP %s request", r.Method)
}
```
should be replaced with
```go
func Handle(w http.ReponseWriter, r *http.Request) {
klog.InfoS("Received HTTP request", httpRequestLog(r)...)
handle(w, r)
}
func httpRequestLog(r *http.Request) []interface{} {
return []interface{}{
"verb", r.Method,
}
}
```
### Using ErrorS
With `klog` structured logging borrowing the interface from [logr] it also inherits it's differences in semantic of