21
vendor/k8s.io/apiserver/pkg/server/healthz/doc.go
generated
vendored
Normal file
21
vendor/k8s.io/apiserver/pkg/server/healthz/doc.go
generated
vendored
Normal file
@@ -0,0 +1,21 @@
|
||||
/*
|
||||
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 healthz implements basic http server health checking.
|
||||
// Usage:
|
||||
// import "k8s.io/apiserver/pkg/server/healthz"
|
||||
// healthz.DefaultHealthz()
|
||||
package healthz // import "k8s.io/apiserver/pkg/server/healthz"
|
||||
228
vendor/k8s.io/apiserver/pkg/server/healthz/healthz.go
generated
vendored
Normal file
228
vendor/k8s.io/apiserver/pkg/server/healthz/healthz.go
generated
vendored
Normal file
@@ -0,0 +1,228 @@
|
||||
/*
|
||||
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 healthz
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"fmt"
|
||||
"net/http"
|
||||
"strings"
|
||||
"sync"
|
||||
"sync/atomic"
|
||||
"time"
|
||||
|
||||
"k8s.io/klog"
|
||||
|
||||
"k8s.io/apimachinery/pkg/util/sets"
|
||||
"k8s.io/apimachinery/pkg/util/wait"
|
||||
)
|
||||
|
||||
// HealthzChecker is a named healthz checker.
|
||||
type HealthzChecker interface {
|
||||
Name() string
|
||||
Check(req *http.Request) error
|
||||
}
|
||||
|
||||
var defaultHealthz = sync.Once{}
|
||||
|
||||
// DefaultHealthz installs the default healthz check to the http.DefaultServeMux.
|
||||
func DefaultHealthz(checks ...HealthzChecker) {
|
||||
defaultHealthz.Do(func() {
|
||||
InstallHandler(http.DefaultServeMux, checks...)
|
||||
})
|
||||
}
|
||||
|
||||
// PingHealthz returns true automatically when checked
|
||||
var PingHealthz HealthzChecker = ping{}
|
||||
|
||||
// ping implements the simplest possible healthz checker.
|
||||
type ping struct{}
|
||||
|
||||
func (ping) Name() string {
|
||||
return "ping"
|
||||
}
|
||||
|
||||
// PingHealthz is a health check that returns true.
|
||||
func (ping) Check(_ *http.Request) error {
|
||||
return nil
|
||||
}
|
||||
|
||||
// LogHealthz returns true if logging is not blocked
|
||||
var LogHealthz HealthzChecker = &log{}
|
||||
|
||||
type log struct {
|
||||
startOnce sync.Once
|
||||
lastVerified atomic.Value
|
||||
}
|
||||
|
||||
func (l *log) Name() string {
|
||||
return "log"
|
||||
}
|
||||
|
||||
func (l *log) Check(_ *http.Request) error {
|
||||
l.startOnce.Do(func() {
|
||||
l.lastVerified.Store(time.Now())
|
||||
go wait.Forever(func() {
|
||||
klog.Flush()
|
||||
l.lastVerified.Store(time.Now())
|
||||
}, time.Minute)
|
||||
})
|
||||
|
||||
lastVerified := l.lastVerified.Load().(time.Time)
|
||||
if time.Since(lastVerified) < (2 * time.Minute) {
|
||||
return nil
|
||||
}
|
||||
return fmt.Errorf("logging blocked")
|
||||
}
|
||||
|
||||
// NamedCheck returns a healthz checker for the given name and function.
|
||||
func NamedCheck(name string, check func(r *http.Request) error) HealthzChecker {
|
||||
return &healthzCheck{name, check}
|
||||
}
|
||||
|
||||
// InstallHandler registers handlers for health checking on the path
|
||||
// "/healthz" to mux. *All handlers* for mux must be specified in
|
||||
// exactly one call to InstallHandler. Calling InstallHandler more
|
||||
// than once for the same mux will result in a panic.
|
||||
func InstallHandler(mux mux, checks ...HealthzChecker) {
|
||||
InstallPathHandler(mux, "/healthz", checks...)
|
||||
}
|
||||
|
||||
// InstallPathHandler registers handlers for health checking on
|
||||
// a specific path to mux. *All handlers* for the path must be
|
||||
// specified in exactly one call to InstallPathHandler. Calling
|
||||
// InstallPathHandler more than once for the same path and mux will
|
||||
// result in a panic.
|
||||
func InstallPathHandler(mux mux, path string, checks ...HealthzChecker) {
|
||||
if len(checks) == 0 {
|
||||
klog.V(5).Info("No default health checks specified. Installing the ping handler.")
|
||||
checks = []HealthzChecker{PingHealthz}
|
||||
}
|
||||
|
||||
klog.V(5).Info("Installing healthz checkers:", formatQuoted(checkerNames(checks...)...))
|
||||
|
||||
mux.Handle(path, handleRootHealthz(checks...))
|
||||
for _, check := range checks {
|
||||
mux.Handle(fmt.Sprintf("%s/%v", path, check.Name()), adaptCheckToHandler(check.Check))
|
||||
}
|
||||
}
|
||||
|
||||
// mux is an interface describing the methods InstallHandler requires.
|
||||
type mux interface {
|
||||
Handle(pattern string, handler http.Handler)
|
||||
}
|
||||
|
||||
// healthzCheck implements HealthzChecker on an arbitrary name and check function.
|
||||
type healthzCheck struct {
|
||||
name string
|
||||
check func(r *http.Request) error
|
||||
}
|
||||
|
||||
var _ HealthzChecker = &healthzCheck{}
|
||||
|
||||
func (c *healthzCheck) Name() string {
|
||||
return c.name
|
||||
}
|
||||
|
||||
func (c *healthzCheck) Check(r *http.Request) error {
|
||||
return c.check(r)
|
||||
}
|
||||
|
||||
// getExcludedChecks extracts the health check names to be excluded from the query param
|
||||
func getExcludedChecks(r *http.Request) sets.String {
|
||||
checks, found := r.URL.Query()["exclude"]
|
||||
if found {
|
||||
return sets.NewString(checks...)
|
||||
}
|
||||
return sets.NewString()
|
||||
}
|
||||
|
||||
// handleRootHealthz returns an http.HandlerFunc that serves the provided checks.
|
||||
func handleRootHealthz(checks ...HealthzChecker) http.HandlerFunc {
|
||||
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
|
||||
failed := false
|
||||
excluded := getExcludedChecks(r)
|
||||
var verboseOut bytes.Buffer
|
||||
for _, check := range checks {
|
||||
// no-op the check if we've specified we want to exclude the check
|
||||
if excluded.Has(check.Name()) {
|
||||
excluded.Delete(check.Name())
|
||||
fmt.Fprintf(&verboseOut, "[+]%v excluded: ok\n", check.Name())
|
||||
continue
|
||||
}
|
||||
if err := check.Check(r); err != nil {
|
||||
// don't include the error since this endpoint is public. If someone wants more detail
|
||||
// they should have explicit permission to the detailed checks.
|
||||
klog.V(6).Infof("healthz check %v failed: %v", check.Name(), err)
|
||||
fmt.Fprintf(&verboseOut, "[-]%v failed: reason withheld\n", check.Name())
|
||||
failed = true
|
||||
} else {
|
||||
fmt.Fprintf(&verboseOut, "[+]%v ok\n", check.Name())
|
||||
}
|
||||
}
|
||||
if excluded.Len() > 0 {
|
||||
fmt.Fprintf(&verboseOut, "warn: some health checks cannot be excluded: no matches for %v\n", formatQuoted(excluded.List()...))
|
||||
klog.Warningf("cannot exclude some health checks, no health checks are installed matching %v",
|
||||
formatQuoted(excluded.List()...))
|
||||
}
|
||||
// always be verbose on failure
|
||||
if failed {
|
||||
http.Error(w, fmt.Sprintf("%vhealthz check failed", verboseOut.String()), http.StatusInternalServerError)
|
||||
return
|
||||
}
|
||||
|
||||
if _, found := r.URL.Query()["verbose"]; !found {
|
||||
fmt.Fprint(w, "ok")
|
||||
return
|
||||
}
|
||||
|
||||
verboseOut.WriteTo(w)
|
||||
fmt.Fprint(w, "healthz check passed\n")
|
||||
})
|
||||
}
|
||||
|
||||
// adaptCheckToHandler returns an http.HandlerFunc that serves the provided checks.
|
||||
func adaptCheckToHandler(c func(r *http.Request) error) http.HandlerFunc {
|
||||
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
|
||||
err := c(r)
|
||||
if err != nil {
|
||||
http.Error(w, fmt.Sprintf("internal server error: %v", err), http.StatusInternalServerError)
|
||||
} else {
|
||||
fmt.Fprint(w, "ok")
|
||||
}
|
||||
})
|
||||
}
|
||||
|
||||
// checkerNames returns the names of the checks in the same order as passed in.
|
||||
func checkerNames(checks ...HealthzChecker) []string {
|
||||
// accumulate the names of checks for printing them out.
|
||||
checkerNames := make([]string, 0, len(checks))
|
||||
for _, check := range checks {
|
||||
checkerNames = append(checkerNames, check.Name())
|
||||
}
|
||||
return checkerNames
|
||||
}
|
||||
|
||||
// formatQuoted returns a formatted string of the health check names,
|
||||
// preserving the order passed in.
|
||||
func formatQuoted(names ...string) string {
|
||||
quoted := make([]string, 0, len(names))
|
||||
for _, name := range names {
|
||||
quoted = append(quoted, fmt.Sprintf("%q", name))
|
||||
}
|
||||
return strings.Join(quoted, ",")
|
||||
}
|
||||
Reference in New Issue
Block a user