Import of https://github.com/ciena/voltctl at commit 40d61fbf3f910ed4017cf67c9c79e8e1f82a33a5
Change-Id: I8464c59e60d76cb8612891db3303878975b5416c
diff --git a/vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go b/vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go
new file mode 100644
index 0000000..76e203b
--- /dev/null
+++ b/vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go
@@ -0,0 +1,173 @@
+/*
+Copyright 2014 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 runtime
+
+import (
+ "fmt"
+ "runtime"
+ "sync"
+ "time"
+
+ "github.com/golang/glog"
+)
+
+var (
+ // ReallyCrash controls the behavior of HandleCrash and now defaults
+ // true. It's still exposed so components can optionally set to false
+ // to restore prior behavior.
+ ReallyCrash = true
+)
+
+// PanicHandlers is a list of functions which will be invoked when a panic happens.
+var PanicHandlers = []func(interface{}){logPanic}
+
+// HandleCrash simply catches a crash and logs an error. Meant to be called via
+// defer. Additional context-specific handlers can be provided, and will be
+// called in case of panic. HandleCrash actually crashes, after calling the
+// handlers and logging the panic message.
+//
+// TODO: remove this function. We are switching to a world where it's safe for
+// apiserver to panic, since it will be restarted by kubelet. At the beginning
+// of the Kubernetes project, nothing was going to restart apiserver and so
+// catching panics was important. But it's actually much simpler for monitoring
+// software if we just exit when an unexpected panic happens.
+func HandleCrash(additionalHandlers ...func(interface{})) {
+ if r := recover(); r != nil {
+ for _, fn := range PanicHandlers {
+ fn(r)
+ }
+ for _, fn := range additionalHandlers {
+ fn(r)
+ }
+ if ReallyCrash {
+ // Actually proceed to panic.
+ panic(r)
+ }
+ }
+}
+
+// logPanic logs the caller tree when a panic occurs.
+func logPanic(r interface{}) {
+ callers := getCallers(r)
+ if _, ok := r.(string); ok {
+ glog.Errorf("Observed a panic: %s\n%v", r, callers)
+ } else {
+ glog.Errorf("Observed a panic: %#v (%v)\n%v", r, r, callers)
+ }
+}
+
+func getCallers(r interface{}) string {
+ callers := ""
+ for i := 0; true; i++ {
+ _, file, line, ok := runtime.Caller(i)
+ if !ok {
+ break
+ }
+ callers = callers + fmt.Sprintf("%v:%v\n", file, line)
+ }
+
+ return callers
+}
+
+// ErrorHandlers is a list of functions which will be invoked when an unreturnable
+// error occurs.
+// TODO(lavalamp): for testability, this and the below HandleError function
+// should be packaged up into a testable and reusable object.
+var ErrorHandlers = []func(error){
+ logError,
+ (&rudimentaryErrorBackoff{
+ lastErrorTime: time.Now(),
+ // 1ms was the number folks were able to stomach as a global rate limit.
+ // If you need to log errors more than 1000 times a second you
+ // should probably consider fixing your code instead. :)
+ minPeriod: time.Millisecond,
+ }).OnError,
+}
+
+// HandlerError is a method to invoke when a non-user facing piece of code cannot
+// return an error and needs to indicate it has been ignored. Invoking this method
+// is preferable to logging the error - the default behavior is to log but the
+// errors may be sent to a remote server for analysis.
+func HandleError(err error) {
+ // this is sometimes called with a nil error. We probably shouldn't fail and should do nothing instead
+ if err == nil {
+ return
+ }
+
+ for _, fn := range ErrorHandlers {
+ fn(err)
+ }
+}
+
+// logError prints an error with the call stack of the location it was reported
+func logError(err error) {
+ glog.ErrorDepth(2, err)
+}
+
+type rudimentaryErrorBackoff struct {
+ minPeriod time.Duration // immutable
+ // TODO(lavalamp): use the clock for testability. Need to move that
+ // package for that to be accessible here.
+ lastErrorTimeLock sync.Mutex
+ lastErrorTime time.Time
+}
+
+// OnError will block if it is called more often than the embedded period time.
+// This will prevent overly tight hot error loops.
+func (r *rudimentaryErrorBackoff) OnError(error) {
+ r.lastErrorTimeLock.Lock()
+ defer r.lastErrorTimeLock.Unlock()
+ d := time.Since(r.lastErrorTime)
+ if d < r.minPeriod {
+ // If the time moves backwards for any reason, do nothing
+ time.Sleep(r.minPeriod - d)
+ }
+ r.lastErrorTime = time.Now()
+}
+
+// GetCaller returns the caller of the function that calls it.
+func GetCaller() string {
+ var pc [1]uintptr
+ runtime.Callers(3, pc[:])
+ f := runtime.FuncForPC(pc[0])
+ if f == nil {
+ return fmt.Sprintf("Unable to find caller")
+ }
+ return f.Name()
+}
+
+// RecoverFromPanic replaces the specified error with an error containing the
+// original error, and the call tree when a panic occurs. This enables error
+// handlers to handle errors and panics the same way.
+func RecoverFromPanic(err *error) {
+ if r := recover(); r != nil {
+ callers := getCallers(r)
+
+ *err = fmt.Errorf(
+ "recovered from panic %q. (err=%v) Call stack:\n%v",
+ r,
+ *err,
+ callers)
+ }
+}
+
+// Must panics on non-nil errors. Useful to handling programmer level errors.
+func Must(err error) {
+ if err != nil {
+ panic(err)
+ }
+}