-
Notifications
You must be signed in to change notification settings - Fork 25
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
[VC-35738] Log with klog to stdout and stderr in Kubernetes text form…
…at (#596) * Log with klog to stdout and stderr in Kubernetes text format Signed-off-by: Richard Wall <[email protected]> Co-authored-by: Maël Valais <[email protected]>
- Loading branch information
Showing
6 changed files
with
620 additions
and
12 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
|
|
@@ -6,3 +6,6 @@ config: | |
| authentication: | ||
| venafiConnection: | ||
| enabled: true | ||
|
|
||
| extraArgs: | ||
| - --logging-format=json | ||
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,8 +1,161 @@ | ||
| package logs | ||
|
|
||
| import ( | ||
| "bytes" | ||
| "fmt" | ||
| "log" | ||
| "log/slog" | ||
| "os" | ||
| "strings" | ||
|
|
||
| "github.com/spf13/pflag" | ||
| "k8s.io/apimachinery/pkg/util/runtime" | ||
| "k8s.io/apimachinery/pkg/util/sets" | ||
| "k8s.io/component-base/featuregate" | ||
| "k8s.io/component-base/logs" | ||
| logsapi "k8s.io/component-base/logs/api/v1" | ||
| _ "k8s.io/component-base/logs/json/register" | ||
| ) | ||
|
|
||
| // venafi-kubernetes-agent follows [Kubernetes Logging Conventions] and writes | ||
| // logs in [Kubernetes text logging format] by default. It does not support | ||
| // named levels (aka. severity), instead it uses arbitrary levels. Errors and | ||
| // warnings are logged to stderr and Info messages to stdout, because that is | ||
| // how some cloud logging systems (notably Google Cloud Logs Explorer) assign a | ||
| // severity (INFO or ERROR) in the UI. The agent's and vcert's logs are written | ||
| // logged as Info messages with level=0. | ||
| // | ||
| // Further reading: | ||
| // - [Kubernetes logging conventions](https://github.com/kubernetes/community/blob/master/contributors/devel/sig-instrumentation/logging.md) | ||
| // - [Kubernetes text logging format](https://github.com/kubernetes/community/blob/master/contributors/devel/sig-instrumentation/logging.md#text-logging-format) | ||
| // - [Why not named levels, like Info/Warning/Error?](https://github.com/go-logr/logr?tab=readme-ov-file#why-not-named-levels-like-infowarningerror) | ||
| // - [GKE logs best practices](https://cloud.google.com/kubernetes-engine/docs/concepts/about-logs#best_practices) | ||
| // - [Structured Logging KEP](https://github.com/kubernetes/enhancements/blob/master/keps/sig-instrumentation/1602-structured-logging/README.md) | ||
| // - [Examples of using k8s.io/component-base/logs](https://github.com/kubernetes/kubernetes/tree/master/staging/src/k8s.io/component-base/logs/example), | ||
| // upon which this code was based. | ||
|
|
||
| var ( | ||
| // This is the Agent's logger. For now, it is still a *log.Logger, but we | ||
| // mean to migrate everything to slog with the klog backend. We avoid using | ||
| // log.Default because log.Default is already used by the VCert library, and | ||
| // we need to keep the agent's logger from the VCert's logger to be able to | ||
| // remove the `vCert: ` prefix from the VCert logs. | ||
| Log *log.Logger | ||
|
|
||
| // All but the essential logging flags will be hidden to avoid overwhelming | ||
| // the user. The hidden flags can still be used. For example if a user does | ||
| // not like the split-stream behavior and a Venafi field engineer can | ||
| // instruct them to patch --log-json-split-stream=false on to the Deployment | ||
| // arguments. | ||
| visibleFlagNames = sets.New[string]("v", "vmodule", "logging-format") | ||
| // This default logging configuration will be updated with values from the | ||
| // logging flags, even those that are hidden. | ||
| configuration = logsapi.NewLoggingConfiguration() | ||
| // Logging features will be added to this feature gate, but the | ||
| // feature-gates flag will be hidden from the user. | ||
| features = featuregate.NewFeatureGate() | ||
| ) | ||
|
|
||
| var Log = log.New(os.Stderr, "", log.LstdFlags) | ||
| func init() { | ||
| runtime.Must(logsapi.AddFeatureGates(features)) | ||
| // Turn on ALPHA options to enable the split-stream logging options. | ||
| runtime.Must(features.OverrideDefault(logsapi.LoggingAlphaOptions, true)) | ||
| } | ||
|
|
||
| // AddFlags adds log related flags to the supplied flag set. | ||
| // | ||
| // The split-stream options are enabled by default, so that errors are logged to | ||
| // stderr and info to stdout, allowing cloud logging systems to assign a | ||
| // severity INFO or ERROR to the messages. | ||
| func AddFlags(fs *pflag.FlagSet) { | ||
| var tfs pflag.FlagSet | ||
| logsapi.AddFlags(configuration, &tfs) | ||
| features.AddFlag(&tfs) | ||
| tfs.VisitAll(func(f *pflag.Flag) { | ||
| if !visibleFlagNames.Has(f.Name) { | ||
| tfs.MarkHidden(f.Name) | ||
| } | ||
|
|
||
| // The original usage string includes details about how | ||
| // JSON logging is only available when BETA logging features are | ||
| // enabled, but that's not relevant here because the feature is enabled | ||
| // by default. | ||
| if f.Name == "logging-format" { | ||
| f.Usage = `Sets the log format. Permitted formats: "json", "text".` | ||
| } | ||
| if f.Name == "log-text-split-stream" { | ||
| f.DefValue = "true" | ||
| runtime.Must(f.Value.Set("true")) | ||
| } | ||
| if f.Name == "log-json-split-stream" { | ||
| f.DefValue = "true" | ||
| runtime.Must(f.Value.Set("true")) | ||
| } | ||
|
|
||
| // Since `--v` (which is the long form of `-v`) isn't the standard in | ||
| // our projects (it only exists in cert-manager, webhook, and such), | ||
| // let's rename it to the more common `--log-level`, which appears in | ||
| // openshift-routes, csi-driver, trust-manager, and approver-policy. | ||
| // More details at: | ||
| // https://github.com/jetstack/jetstack-secure/pull/596#issuecomment-2421708181 | ||
| if f.Name == "v" { | ||
| f.Name = "log-level" | ||
| f.Shorthand = "v" | ||
| } | ||
| }) | ||
| fs.AddFlagSet(&tfs) | ||
| } | ||
|
|
||
| // Initialize uses k8s.io/component-base/logs, to configure the following global | ||
| // loggers: log, slog, and klog. All are configured to write in the same format. | ||
| func Initialize() { | ||
| // This configures the global logger in klog *and* slog, if compiled with Go | ||
| // >= 1.21. | ||
| logs.InitLogs() | ||
| if err := logsapi.ValidateAndApply(configuration, features); err != nil { | ||
| fmt.Fprintf(os.Stderr, "Error in logging configuration: %v\n", err) | ||
| os.Exit(2) | ||
| } | ||
|
|
||
| // Thanks to logs.InitLogs, slog.Default now uses klog as its backend. Thus, | ||
| // the client-go library, which relies on klog.Info, has the same logger as | ||
| // the agent, which still uses log.Printf. | ||
| slog := slog.Default() | ||
|
|
||
| Log = &log.Logger{} | ||
| Log.SetOutput(LogToSlogWriter{Slog: slog, Source: "agent"}) | ||
|
|
||
| // Let's make sure the VCert library, which is the only library we import to | ||
| // be using the global log.Default, also uses the common slog logger. | ||
| vcertLog := log.Default() | ||
| vcertLog.SetOutput(LogToSlogWriter{Slog: slog, Source: "vcert"}) | ||
| // This is a work around for a bug in vcert where it adds a `vCert: ` prefix | ||
| // to the global log logger. It can be removed when this is fixed upstream | ||
| // in vcert: https://github.com/Venafi/vcert/pull/512 | ||
| vcertLog.SetPrefix("") | ||
| } | ||
|
|
||
| type LogToSlogWriter struct { | ||
| Slog *slog.Logger | ||
| Source string | ||
| } | ||
|
|
||
| func (w LogToSlogWriter) Write(p []byte) (n int, err error) { | ||
| // log.Printf writes a newline at the end of the message, so we need to trim | ||
| // it. | ||
| p = bytes.TrimSuffix(p, []byte("\n")) | ||
|
|
||
| message := string(p) | ||
| if strings.Contains(message, "error") || | ||
| strings.Contains(message, "failed") || | ||
| strings.Contains(message, "fatal") || | ||
| strings.Contains(message, "Failed") || | ||
| strings.Contains(message, "While evaluating configuration") || | ||
| strings.Contains(message, "data-path override present") || | ||
| strings.Contains(message, "Cannot marshal readings") { | ||
| w.Slog.With("source", w.Source).Error(message) | ||
| } else { | ||
| w.Slog.With("source", w.Source).Info(message) | ||
| } | ||
| return len(p), nil | ||
| } |
Oops, something went wrong.