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package health
import (
"context"
"fmt"
"github.com/sirupsen/logrus"
"net/http"
"sync"
"time"
rrhttp "github.com/spiral/roadrunner/service/http"
)
const (
// ID declares public service name.
ID = "health"
// maxHeaderSize declares max header size for prometheus server
maxHeaderSize = 1024 * 1024 * 100 // 104MB
)
// Service to serve an endpoint for checking the health of the worker pool
type Service struct {
cfg *Config
log *logrus.Logger
mu sync.Mutex
http *http.Server
httpService *rrhttp.Service
}
// Init health service
func (s *Service) Init(cfg *Config, r *rrhttp.Service, log *logrus.Logger) (bool, error) {
// Ensure the httpService is set
if r == nil {
return false, nil
}
s.cfg = cfg
s.log = log
s.httpService = r
return true, nil
}
// Serve the health endpoint
func (s *Service) Serve() error {
// Configure and start the http server
s.mu.Lock()
s.http = &http.Server{
Addr: s.cfg.Address,
Handler: s,
IdleTimeout: time.Hour * 24,
ReadTimeout: time.Minute * 60,
MaxHeaderBytes: maxHeaderSize,
ReadHeaderTimeout: time.Minute * 60,
WriteTimeout: time.Minute * 60,
}
s.mu.Unlock()
err := s.http.ListenAndServe()
if err != nil && err != http.ErrServerClosed {
return err
}
return nil
}
// Stop the health endpoint
func (s *Service) Stop() {
s.mu.Lock()
defer s.mu.Unlock()
if s.http != nil {
// gracefully stop the server
go func() {
err := s.http.Shutdown(context.Background())
if err != nil && err != http.ErrServerClosed {
s.log.Error(fmt.Errorf("error shutting down the metrics server: error %v", err))
}
}()
}
}
// ServeHTTP returns the health of the pool of workers
func (s *Service) ServeHTTP(w http.ResponseWriter, r *http.Request) {
status := http.StatusOK
if !s.isHealthy() {
status = http.StatusInternalServerError
}
w.WriteHeader(status)
}
// isHealthy checks the server, pool and ensures at least one worker is active
func (s *Service) isHealthy() bool {
httpService := s.httpService
if httpService == nil {
return false
}
server := httpService.Server()
if server == nil {
return false
}
pool := server.Pool()
if pool == nil {
return false
}
// Ensure at least one worker is active
for _, w := range pool.Workers() {
if w.State().IsActive() {
return true
}
}
return false
}
|
