mirror of
https://github.com/caddyserver/caddy.git
synced 2024-12-29 15:13:49 +03:00
86 lines
2.2 KiB
Go
Executable file
86 lines
2.2 KiB
Go
Executable file
// Copyright 2015 Matthew Holt and The Caddy 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 reverseproxy
|
|
|
|
import (
|
|
"net/http"
|
|
"time"
|
|
)
|
|
|
|
// Upstream represents the interface that must be satisfied to use the healthchecker.
|
|
type Upstream interface {
|
|
SetHealthiness(bool)
|
|
}
|
|
|
|
// HealthChecker represents a worker that periodically evaluates if proxy upstream host is healthy.
|
|
type HealthChecker struct {
|
|
upstream Upstream
|
|
Ticker *time.Ticker
|
|
HTTPClient *http.Client
|
|
StopChan chan bool
|
|
}
|
|
|
|
// ScheduleChecks periodically runs health checks against an upstream host.
|
|
func (h *HealthChecker) ScheduleChecks(url string) {
|
|
// check if a host is healthy on start vs waiting for timer
|
|
h.upstream.SetHealthiness(h.IsHealthy(url))
|
|
stop := make(chan bool)
|
|
h.StopChan = stop
|
|
|
|
go func() {
|
|
for {
|
|
select {
|
|
case <-h.Ticker.C:
|
|
h.upstream.SetHealthiness(h.IsHealthy(url))
|
|
case <-stop:
|
|
return
|
|
}
|
|
}
|
|
}()
|
|
}
|
|
|
|
// Stop stops the healthchecker from makeing further requests.
|
|
func (h *HealthChecker) Stop() {
|
|
h.Ticker.Stop()
|
|
close(h.StopChan)
|
|
}
|
|
|
|
// IsHealthy attempts to check if a upstream host is healthy.
|
|
func (h *HealthChecker) IsHealthy(url string) bool {
|
|
req, err := http.NewRequest(http.MethodGet, url, nil)
|
|
if err != nil {
|
|
return false
|
|
}
|
|
|
|
resp, err := h.HTTPClient.Do(req)
|
|
if err != nil {
|
|
return false
|
|
}
|
|
|
|
if resp.StatusCode < 200 || resp.StatusCode >= 400 {
|
|
return false
|
|
}
|
|
|
|
return true
|
|
}
|
|
|
|
// NewHealthCheckWorker returns a new instance of a HealthChecker.
|
|
func NewHealthCheckWorker(u Upstream, interval time.Duration, client *http.Client) *HealthChecker {
|
|
return &HealthChecker{
|
|
upstream: u,
|
|
Ticker: time.NewTicker(interval),
|
|
HTTPClient: client,
|
|
}
|
|
}
|