108 lines
2.6 KiB
Go
108 lines
2.6 KiB
Go
|
package main
|
||
|
|
|
||
|
|
import (
|
||
|
|
"context"
|
||
|
|
"fmt"
|
||
|
|
"log"
|
||
|
|
"net"
|
||
|
|
"net/http"
|
||
|
|
"os"
|
||
|
|
|
||
|
|
"github.com/gorilla/handlers"
|
||
|
|
"github.com/prometheus/client_golang/prometheus/promhttp"
|
||
|
|
)
|
||
|
|
|
||
|
|
// The http server output.
|
||
|
|
type HTTPOutput struct {
|
||
|
|
server *http.Server
|
||
|
|
mux *http.ServeMux
|
||
|
|
config *HTTPOutputConfig
|
||
|
|
}
|
||
|
|
|
||
|
|
// Make a new http output controller.
|
||
|
|
func NewHTTPOutput() *HTTPOutput {
|
||
|
|
// Create the server.
|
||
|
|
s := new(HTTPOutput)
|
||
|
|
s.server = &http.Server{}
|
||
|
|
// Add update configurations.
|
||
|
|
s.Reload()
|
||
|
|
|
||
|
|
return s
|
||
|
|
}
|
||
|
|
|
||
|
|
// Creates the handlers and configures the server.
|
||
|
|
func (s *HTTPOutput) AddHandlers() {
|
||
|
|
// Make a new handler to replace old.
|
||
|
|
mux := http.NewServeMux()
|
||
|
|
s.mux = mux
|
||
|
|
s.server.Handler = mux
|
||
|
|
|
||
|
|
// Register handlers.
|
||
|
|
mux.Handle(s.config.MetricsPath, handlers.CombinedLoggingHandler(os.Stdout, promhttp.HandlerFor(app.registry, promhttp.HandlerOpts{})))
|
||
|
|
mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
|
||
|
|
w.Write([]byte(`<html>
|
||
|
|
<head><title>Metrics Exporter</title></head>
|
||
|
|
<body>
|
||
|
|
<h1>Metrics Exporter</h1>
|
||
|
|
<p><a href='` + s.config.MetricsPath + `'>Metrics</a></p>
|
||
|
|
</body>
|
||
|
|
</html>`))
|
||
|
|
})
|
||
|
|
}
|
||
|
|
|
||
|
|
// Reload configurations.
|
||
|
|
func (s *HTTPOutput) Reload() {
|
||
|
|
// Update config reference.
|
||
|
|
s.config = &app.config.HTTP
|
||
|
|
// Update the address.
|
||
|
|
s.server.Addr = fmt.Sprintf("%s:%d", s.config.BindAddr, s.config.Port)
|
||
|
|
// Update handlers incase the path was re-configured.
|
||
|
|
s.AddHandlers()
|
||
|
|
}
|
||
|
|
|
||
|
|
// Returns rather or not output is enabled.
|
||
|
|
func (s *HTTPOutput) OutputEnabled() bool {
|
||
|
|
return s.config.Enabled
|
||
|
|
}
|
||
|
|
|
||
|
|
// Start the HTTP output server.
|
||
|
|
func (s *HTTPOutput) Start(ctx context.Context) {
|
||
|
|
isListening := make(chan bool)
|
||
|
|
// Start server.
|
||
|
|
go s.StartWithIsListening(ctx, isListening)
|
||
|
|
// Allow the http server to initialize.
|
||
|
|
<-isListening
|
||
|
|
}
|
||
|
|
|
||
|
|
// Starts the HTTP output server with a listening channel.
|
||
|
|
func (s *HTTPOutput) StartWithIsListening(ctx context.Context, isListening chan bool) {
|
||
|
|
// If http is disabled, stop here.
|
||
|
|
if !s.config.Enabled {
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
// Watch the background context for when we need to shutdown.
|
||
|
|
go func() {
|
||
|
|
<-ctx.Done()
|
||
|
|
err := s.server.Shutdown(context.Background())
|
||
|
|
if err != nil {
|
||
|
|
// Error from closing listeners, or context timeout:
|
||
|
|
log.Println("Error shutting down http server:", err)
|
||
|
|
}
|
||
|
|
}()
|
||
|
|
|
||
|
|
// Start the server.
|
||
|
|
log.Println("Starting http server:", s.server.Addr)
|
||
|
|
l, err := net.Listen("tcp", s.server.Addr)
|
||
|
|
if err != nil {
|
||
|
|
log.Fatal("Listen: ", err)
|
||
|
|
}
|
||
|
|
// Now notify we are listening.
|
||
|
|
isListening <- true
|
||
|
|
// Serve http server on the listening port.
|
||
|
|
err = s.server.Serve(l)
|
||
|
|
if err != nil {
|
||
|
|
log.Println("HTTP server failure:", err)
|
||
|
|
}
|
||
|
|
}
|