grafana/pkg/server/server.go

346 lines
8.6 KiB
Go

package server
import (
"context"
"errors"
"flag"
"fmt"
"io/ioutil"
"net"
"os"
"path/filepath"
"strconv"
"sync"
"time"
"github.com/facebookgo/inject"
"golang.org/x/sync/errgroup"
"github.com/grafana/grafana/pkg/api"
"github.com/grafana/grafana/pkg/api/routing"
"github.com/grafana/grafana/pkg/bus"
_ "github.com/grafana/grafana/pkg/extensions"
"github.com/grafana/grafana/pkg/infra/localcache"
"github.com/grafana/grafana/pkg/infra/log"
_ "github.com/grafana/grafana/pkg/infra/metrics"
_ "github.com/grafana/grafana/pkg/infra/remotecache"
_ "github.com/grafana/grafana/pkg/infra/serverlock"
_ "github.com/grafana/grafana/pkg/infra/tracing"
_ "github.com/grafana/grafana/pkg/infra/usagestats"
"github.com/grafana/grafana/pkg/login"
"github.com/grafana/grafana/pkg/login/social"
"github.com/grafana/grafana/pkg/middleware"
_ "github.com/grafana/grafana/pkg/plugins"
"github.com/grafana/grafana/pkg/registry"
_ "github.com/grafana/grafana/pkg/services/alerting"
_ "github.com/grafana/grafana/pkg/services/auth"
_ "github.com/grafana/grafana/pkg/services/cleanup"
_ "github.com/grafana/grafana/pkg/services/notifications"
_ "github.com/grafana/grafana/pkg/services/provisioning"
_ "github.com/grafana/grafana/pkg/services/rendering"
_ "github.com/grafana/grafana/pkg/services/search"
_ "github.com/grafana/grafana/pkg/services/sqlstore"
"github.com/grafana/grafana/pkg/setting"
"github.com/grafana/grafana/pkg/util/errutil"
)
// Config contains parameters for the New function.
type Config struct {
ConfigFile string
HomePath string
PidFile string
Version string
Commit string
BuildBranch string
Listener net.Listener
}
// New returns a new instance of Server.
func New(cfg Config) (*Server, error) {
rootCtx, shutdownFn := context.WithCancel(context.Background())
childRoutines, childCtx := errgroup.WithContext(rootCtx)
s := &Server{
context: childCtx,
shutdownFn: shutdownFn,
childRoutines: childRoutines,
log: log.New("server"),
cfg: setting.NewCfg(),
configFile: cfg.ConfigFile,
homePath: cfg.HomePath,
pidFile: cfg.PidFile,
version: cfg.Version,
commit: cfg.Commit,
buildBranch: cfg.BuildBranch,
}
if cfg.Listener != nil {
if err := s.init(&cfg); err != nil {
return nil, err
}
}
return s, nil
}
// Server is responsible for managing the lifecycle of services.
type Server struct {
context context.Context
shutdownFn context.CancelFunc
childRoutines *errgroup.Group
log log.Logger
cfg *setting.Cfg
shutdownReason string
shutdownInProgress bool
isInitialized bool
mtx sync.Mutex
configFile string
homePath string
pidFile string
version string
commit string
buildBranch string
HTTPServer *api.HTTPServer `inject:""`
}
// init initializes the server and its services.
func (s *Server) init(cfg *Config) error {
s.mtx.Lock()
defer s.mtx.Unlock()
if s.isInitialized {
return nil
}
s.isInitialized = true
s.loadConfiguration()
s.writePIDFile()
login.Init()
social.NewOAuthService()
services := registry.GetServices()
if err := s.buildServiceGraph(services); err != nil {
return err
}
// Initialize services.
for _, service := range services {
if registry.IsDisabled(service.Instance) {
continue
}
if cfg != nil {
if httpS, ok := service.Instance.(*api.HTTPServer); ok {
// Configure the api.HTTPServer if necessary
// Hopefully we can find a better solution, maybe with a more advanced DI framework, f.ex. Dig?
if cfg.Listener != nil {
s.log.Debug("Using provided listener for HTTP server")
httpS.Listener = cfg.Listener
}
}
}
if err := service.Instance.Init(); err != nil {
return errutil.Wrapf(err, "Service init failed")
}
}
return nil
}
// Run initializes and starts services. This will block until all services have
// exited. To initiate shutdown, call the Shutdown method in another goroutine.
func (s *Server) Run() (err error) {
if err = s.init(nil); err != nil {
return
}
services := registry.GetServices()
// Start background services.
for _, svc := range services {
service, ok := svc.Instance.(registry.BackgroundService)
if !ok {
continue
}
if registry.IsDisabled(svc.Instance) {
continue
}
// Variable is needed for accessing loop variable in callback
descriptor := svc
s.childRoutines.Go(func() error {
// Don't start new services when server is shutting down.
if s.shutdownInProgress {
return nil
}
err := service.Run(s.context)
if err != nil {
// Mark that we are in shutdown mode
// So no more services are started
s.shutdownInProgress = true
if err != context.Canceled {
// Server has crashed.
s.log.Error("Stopped "+descriptor.Name, "reason", err)
} else {
s.log.Debug("Stopped "+descriptor.Name, "reason", err)
}
return err
}
return nil
})
}
defer func() {
s.log.Debug("Waiting on services...")
if waitErr := s.childRoutines.Wait(); waitErr != nil && !errors.Is(waitErr, context.Canceled) {
s.log.Error("A service failed", "err", waitErr)
if err == nil {
err = waitErr
}
}
}()
s.notifySystemd("READY=1")
return nil
}
func (s *Server) Shutdown(reason string) {
s.log.Info("Shutdown started", "reason", reason)
s.shutdownReason = reason
s.shutdownInProgress = true
// call cancel func on root context
s.shutdownFn()
// wait for child routines
if err := s.childRoutines.Wait(); err != nil && !errors.Is(err, context.Canceled) {
s.log.Error("Failed waiting for services to shutdown", "err", err)
}
}
// ExitCode returns an exit code for a given error.
func (s *Server) ExitCode(reason error) int {
code := 1
if reason == context.Canceled && s.shutdownReason != "" {
reason = fmt.Errorf(s.shutdownReason)
code = 0
}
s.log.Error("Server shutdown", "reason", reason)
return code
}
// writePIDFile retrieves the current process ID and writes it to file.
func (s *Server) writePIDFile() {
if s.pidFile == "" {
return
}
// Ensure the required directory structure exists.
err := os.MkdirAll(filepath.Dir(s.pidFile), 0700)
if err != nil {
s.log.Error("Failed to verify pid directory", "error", err)
os.Exit(1)
}
// Retrieve the PID and write it to file.
pid := strconv.Itoa(os.Getpid())
if err := ioutil.WriteFile(s.pidFile, []byte(pid), 0644); err != nil {
s.log.Error("Failed to write pidfile", "error", err)
os.Exit(1)
}
s.log.Info("Writing PID file", "path", s.pidFile, "pid", pid)
}
// buildServiceGraph builds a graph of services and their dependencies.
func (s *Server) buildServiceGraph(services []*registry.Descriptor) error {
// Specify service dependencies.
objs := []interface{}{
bus.GetBus(),
s.cfg,
routing.NewRouteRegister(middleware.RequestMetrics, middleware.RequestTracing),
localcache.New(5*time.Minute, 10*time.Minute),
s,
}
for _, service := range services {
objs = append(objs, service.Instance)
}
var serviceGraph inject.Graph
// Provide services and their dependencies to the graph.
for _, obj := range objs {
if err := serviceGraph.Provide(&inject.Object{Value: obj}); err != nil {
return errutil.Wrapf(err, "Failed to provide object to the graph")
}
}
// Resolve services and their dependencies.
if err := serviceGraph.Populate(); err != nil {
return errutil.Wrapf(err, "Failed to populate service dependency")
}
return nil
}
// loadConfiguration loads settings and configuration from config files.
func (s *Server) loadConfiguration() {
args := &setting.CommandLineArgs{
Config: s.configFile,
HomePath: s.homePath,
Args: flag.Args(),
}
if err := s.cfg.Load(args); err != nil {
fmt.Fprintf(os.Stderr, "Failed to start grafana. error: %s\n", err.Error())
os.Exit(1)
}
s.log.Info("Starting "+setting.ApplicationName,
"version", s.version,
"commit", s.commit,
"branch", s.buildBranch,
"compiled", time.Unix(setting.BuildStamp, 0),
)
s.cfg.LogConfigSources()
}
// notifySystemd sends state notifications to systemd.
func (s *Server) notifySystemd(state string) {
notifySocket := os.Getenv("NOTIFY_SOCKET")
if notifySocket == "" {
s.log.Debug(
"NOTIFY_SOCKET environment variable empty or unset, can't send systemd notification")
return
}
socketAddr := &net.UnixAddr{
Name: notifySocket,
Net: "unixgram",
}
conn, err := net.DialUnix(socketAddr.Net, nil, socketAddr)
if err != nil {
s.log.Warn("Failed to connect to systemd", "err", err, "socket", notifySocket)
return
}
defer conn.Close()
_, err = conn.Write([]byte(state))
if err != nil {
s.log.Warn("Failed to write notification to systemd", "err", err)
}
}