Initial v1.0.0 commit

vendor/sigs.k8s.io/controller-runtime/pkg/log/log.go

@@ -0,0 +1,99 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+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 log contains utilities for fetching a new logger
+// when one is not already available.
+//
+// The Log Handle
+//
+// This package contains a root logr.Logger Log.  It may be used to
+// get a handle to whatever the root logging implementation is.  By
+// default, no implementation exists, and the handle returns "promises"
+// to loggers.  When the implementation is set using SetLogger, these
+// "promises" will be converted over to real loggers.
+//
+// Logr
+//
+// All logging in controller-runtime is structured, using a set of interfaces
+// defined by a package called logr
+// (https://godoc.org/github.com/go-logr/logr).  The sub-package zap provides
+// helpers for setting up logr backed by Zap (go.uber.org/zap).
+package log
+
+import (
+	"context"
+	"sync"
+	"time"
+
+	"github.com/go-logr/logr"
+)
+
+// SetLogger sets a concrete logging implementation for all deferred Loggers.
+func SetLogger(l logr.Logger) {
+	loggerWasSetLock.Lock()
+	defer loggerWasSetLock.Unlock()
+
+	loggerWasSet = true
+	Log.Fulfill(l)
+}
+
+// It is safe to assume that if this wasn't set within the first 30 seconds of a binaries
+// lifetime, it will never get set. The DelegatingLogger causes a high number of memory
+// allocations when not given an actual Logger, so we set a NullLogger to avoid that.
+//
+// We need to keep the DelegatingLogger because we have various inits() that get a logger from
+// here. They will always get executed before any code that imports controller-runtime
+// has a chance to run and hence to set an actual logger.
+func init() {
+	// Init is blocking, so start a new goroutine
+	go func() {
+		time.Sleep(30 * time.Second)
+		loggerWasSetLock.Lock()
+		defer loggerWasSetLock.Unlock()
+		if !loggerWasSet {
+			Log.Fulfill(NullLogger{})
+		}
+	}()
+}
+
+var (
+	loggerWasSetLock sync.Mutex
+	loggerWasSet     bool
+)
+
+// Log is the base logger used by kubebuilder.  It delegates
+// to another logr.Logger. You *must* call SetLogger to
+// get any actual logging. If SetLogger is not called within
+// the first 30 seconds of a binaries lifetime, it will get
+// set to a NullLogger.
+var Log = NewDelegatingLogger(NullLogger{})
+
+// FromContext returns a logger with predefined values from a context.Context.
+func FromContext(ctx context.Context, keysAndValues ...interface{}) logr.Logger {
+	var log logr.Logger = Log
+	if ctx != nil {
+		if logger := logr.FromContext(ctx); logger != nil {
+			log = logger
+		}
+	}
+	return log.WithValues(keysAndValues...)
+}
+
+// IntoContext takes a context and sets the logger as one of its keys.
+// Use FromContext function to retrieve the logger.
+func IntoContext(ctx context.Context, log logr.Logger) context.Context {
+	return logr.NewContext(ctx, log)
+}