caddy/caddy/caddy.go

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// Package caddy implements the Caddy web server as a service.
//
// To use this package, follow a few simple steps:
//
// 1. Set the AppName and AppVersion variables.
// 2. Call LoadCaddyfile() to get the Caddyfile (it
// might have been piped in as part of a restart).
// You should pass in your own Caddyfile loader.
// 3. Call caddy.Start() to start Caddy, caddy.Stop()
// to stop it, or caddy.Restart() to restart it.
//
// You should use caddy.Wait() to wait for all Caddy servers
// to quit before your process exits.
package caddy
import (
"bytes"
"encoding/gob"
"errors"
"fmt"
"io/ioutil"
"log"
"net"
"os"
"path"
"strings"
"sync"
"time"
"github.com/mholt/caddy/caddy/letsencrypt"
"github.com/mholt/caddy/server"
)
// Configurable application parameters
var (
// AppName is the name of the application.
AppName string
// AppVersion is the version of the application.
AppVersion string
// Quiet when set to true, will not show any informative output on initialization.
Quiet bool
// HTTP2 indicates whether HTTP2 is enabled or not.
HTTP2 bool // TODO: temporary flag until http2 is standard
// PidFile is the path to the pidfile to create.
PidFile string
// GracefulTimeout is the maximum duration of a graceful shutdown.
GracefulTimeout time.Duration
)
var (
// caddyfile is the input configuration text used for this process
caddyfile Input
// caddyfileMu protects caddyfile during changes
caddyfileMu sync.Mutex
// errIncompleteRestart occurs if this process is a fork
// of the parent but no Caddyfile was piped in
errIncompleteRestart = errors.New("incomplete restart")
// servers is a list of all the currently-listening servers
servers []*server.Server
// serversMu protects the servers slice during changes
serversMu sync.Mutex
// wg is used to wait for all servers to shut down
wg sync.WaitGroup
// loadedGob is used if this is a child process as part of
// a graceful restart; it is used to map listeners to their
// index in the list of inherited file descriptors. This
// variable is not safe for concurrent access.
loadedGob caddyfileGob
// startedBefore should be set to true if caddy has been started
// at least once (does not indicate whether currently running).
startedBefore bool
)
const (
// DefaultHost is the default host.
DefaultHost = ""
// DefaultPort is the default port.
DefaultPort = "2015"
// DefaultRoot is the default root folder.
DefaultRoot = "."
)
// Start starts Caddy with the given Caddyfile. If cdyfile
// is nil, the LoadCaddyfile function will be called to get
// one.
//
// This function blocks until all the servers are listening.
//
// Note (POSIX): If Start is called in the child process of a
// restart more than once within the duration of the graceful
// cutoff (i.e. the child process called Start a first time,
// then called Stop, then Start again within the first 5 seconds
// or however long GracefulTimeout is) and the Caddyfiles have
// at least one listener address in common, the second Start
// may fail with "address already in use" as there's no
// guarantee that the parent process has relinquished the
// address before the grace period ends.
func Start(cdyfile Input) (err error) {
// If we return with no errors, we must do two things: tell the
// parent that we succeeded and write to the pidfile.
defer func() {
if err == nil {
signalSuccessToParent() // TODO: Is doing this more than once per process a bad idea? Start could get called more than once in other apps.
if PidFile != "" {
err := writePidFile()
if err != nil {
log.Printf("[ERROR] Could not write pidfile: %v", err)
}
}
}
}()
// Input must never be nil; try to load something
if cdyfile == nil {
cdyfile, err = LoadCaddyfile(nil)
if err != nil {
return err
}
}
caddyfileMu.Lock()
caddyfile = cdyfile
caddyfileMu.Unlock()
// load the server configs (activates Let's Encrypt)
configs, err := loadConfigs(path.Base(cdyfile.Path()), bytes.NewReader(cdyfile.Body()))
if err != nil {
return err
}
// group virtualhosts by address
groupings, err := arrangeBindings(configs)
if err != nil {
return err
}
// Start each server with its one or more configurations
err = startServers(groupings)
if err != nil {
return err
}
startedBefore = true
// Show initialization output
if !Quiet && !IsRestart() {
var checkedFdLimit bool
for _, group := range groupings {
for _, conf := range group.Configs {
// Print address of site
fmt.Println(conf.Address())
// Note if non-localhost site resolves to loopback interface
if group.BindAddr.IP.IsLoopback() && !isLocalhost(conf.Host) {
fmt.Printf("Notice: %s is only accessible on this machine (%s)\n",
conf.Host, group.BindAddr.IP.String())
}
if !checkedFdLimit && !group.BindAddr.IP.IsLoopback() && !isLocalhost(conf.Host) {
checkFdlimit()
checkedFdLimit = true
}
}
}
}
return nil
}
// startServers starts all the servers in groupings,
// taking into account whether or not this process is
// a child from a graceful restart or not. It blocks
// until the servers are listening.
func startServers(groupings bindingGroup) error {
var startupWg sync.WaitGroup
errChan := make(chan error, len(groupings)) // must be buffered to allow Serve functions below to return if stopped later
for _, group := range groupings {
s, err := server.New(group.BindAddr.String(), group.Configs, GracefulTimeout)
if err != nil {
return err
}
s.HTTP2 = HTTP2 // TODO: This setting is temporary
var ln server.ListenerFile
if IsRestart() {
// Look up this server's listener in the map of inherited file descriptors;
// if we don't have one, we must make a new one (later).
if fdIndex, ok := loadedGob.ListenerFds[s.Addr]; ok {
file := os.NewFile(fdIndex, "")
fln, err := net.FileListener(file)
if err != nil {
return err
}
ln, ok = fln.(server.ListenerFile)
if !ok {
return errors.New("listener for " + s.Addr + " was not a ListenerFile")
}
file.Close()
delete(loadedGob.ListenerFds, s.Addr)
}
}
wg.Add(1)
go func(s *server.Server, ln server.ListenerFile) {
defer wg.Done()
// run startup functions that should only execute when
// the original parent process is starting.
if !IsRestart() && !startedBefore {
err := s.RunFirstStartupFuncs()
if err != nil {
errChan <- err
return
}
}
// start the server
if ln != nil {
errChan <- s.Serve(ln)
} else {
errChan <- s.ListenAndServe()
}
}(s, ln)
startupWg.Add(1)
go func(s *server.Server) {
defer startupWg.Done()
s.WaitUntilStarted()
}(s)
serversMu.Lock()
servers = append(servers, s)
serversMu.Unlock()
}
// Close the remaining (unused) file descriptors to free up resources
if IsRestart() {
for key, fdIndex := range loadedGob.ListenerFds {
os.NewFile(fdIndex, "").Close()
delete(loadedGob.ListenerFds, key)
}
}
// Wait for all servers to finish starting
startupWg.Wait()
// Return the first error, if any
select {
case err := <-errChan:
// "use of closed network connection" is normal if it was a graceful shutdown
if err != nil && !strings.Contains(err.Error(), "use of closed network connection") {
return err
}
default:
}
return nil
}
// Stop stops all servers. It blocks until they are all stopped.
// It does NOT execute shutdown callbacks that may have been
// configured by middleware (they must be executed separately).
func Stop() error {
letsencrypt.Deactivate()
serversMu.Lock()
for _, s := range servers {
if err := s.Stop(); err != nil {
log.Printf("[ERROR] Stopping %s: %v", s.Addr, err)
}
}
servers = []*server.Server{} // don't reuse servers
serversMu.Unlock()
return nil
}
// Wait blocks until all servers are stopped.
func Wait() {
wg.Wait()
}
// LoadCaddyfile loads a Caddyfile, prioritizing a Caddyfile
// piped from stdin as part of a restart (only happens on first call
// to LoadCaddyfile). If it is not a restart, this function tries
// calling the user's loader function, and if that returns nil, then
// this function resorts to the default configuration. Thus, if there
// are no other errors, this function always returns at least the
// default Caddyfile.
func LoadCaddyfile(loader func() (Input, error)) (cdyfile Input, err error) {
// If we are a fork, finishing the restart is highest priority;
// piped input is required in this case.
if IsRestart() {
err := gob.NewDecoder(os.Stdin).Decode(&loadedGob)
if err != nil {
return nil, err
}
cdyfile = loadedGob.Caddyfile
}
// Try user's loader
if cdyfile == nil && loader != nil {
cdyfile, err = loader()
}
// Otherwise revert to default
if cdyfile == nil {
cdyfile = DefaultInput()
}
return
}
// CaddyfileFromPipe loads the Caddyfile input from f if f is
// not interactive input. f is assumed to be a pipe or stream,
// such as os.Stdin. If f is not a pipe, no error is returned
// but the Input value will be nil. An error is only returned
// if there was an error reading the pipe, even if the length
// of what was read is 0.
func CaddyfileFromPipe(f *os.File) (Input, error) {
fi, err := f.Stat()
if err == nil && fi.Mode()&os.ModeCharDevice == 0 {
// Note that a non-nil error is not a problem. Windows
// will not create a stdin if there is no pipe, which
// produces an error when calling Stat(). But Unix will
// make one either way, which is why we also check that
// bitmask.
// BUG: Reading from stdin after this fails (e.g. for the let's encrypt email address) (OS X)
confBody, err := ioutil.ReadAll(f)
if err != nil {
return nil, err
}
return CaddyfileInput{
Contents: confBody,
Filepath: f.Name(),
}, nil
}
// not having input from the pipe is not itself an error,
// just means no input to return.
return nil, nil
}
// Caddyfile returns the current Caddyfile
func Caddyfile() Input {
caddyfileMu.Lock()
defer caddyfileMu.Unlock()
return caddyfile
}
// Input represents a Caddyfile; its contents and file path
// (which should include the file name at the end of the path).
// If path does not apply (e.g. piped input) you may use
// any understandable value. The path is mainly used for logging,
// error messages, and debugging.
type Input interface {
// Gets the Caddyfile contents
Body() []byte
// Gets the path to the origin file
Path() string
// IsFile returns true if the original input was a file on the file system
// that could be loaded again later if requested.
IsFile() bool
}