forked from flynn/flynn
/
host.go
514 lines (464 loc) · 15.9 KB
/
host.go
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package main
import (
"bytes"
"encoding/json"
"fmt"
"log"
"net"
"net/url"
"os"
"path/filepath"
"runtime"
"strconv"
"strings"
"syscall"
"github.com/flynn/flynn/bootstrap/discovery"
"github.com/flynn/flynn/host/cli"
"github.com/flynn/flynn/host/config"
"github.com/flynn/flynn/host/logmux"
"github.com/flynn/flynn/host/types"
"github.com/flynn/flynn/host/volume"
"github.com/flynn/flynn/host/volume/manager"
zfsVolume "github.com/flynn/flynn/host/volume/zfs"
"github.com/flynn/flynn/pkg/shutdown"
"github.com/flynn/flynn/pkg/version"
"github.com/flynn/go-docopt"
"github.com/opencontainers/runc/libcontainer"
_ "github.com/opencontainers/runc/libcontainer/nsenter"
"gopkg.in/inconshreveable/log15.v2"
)
const configFile = "/etc/flynn/host.json"
func init() {
cli.Register("daemon", runDaemon, `
usage: flynn-host daemon [options]
options:
--http-port=PORT HTTP port [default: 1113]
--external-ip=IP external IP of host
--listen-ip=IP bind host network services to this IP
--state=PATH path to state file [default: /var/lib/flynn/host-state.bolt]
--id=ID host id
--tags=TAGS host tags (comma separated list of KEY=VAL pairs, used for job constraints in the scheduler)
--force kill all containers booted by flynn-host before starting
--volpath=PATH directory to create volumes in [default: /var/lib/flynn/volumes]
--vol-provider=VOL volume provider [default: zfs]
--backend=BACKEND runner backend [default: libcontainer]
--flynn-init=PATH path to flynn-init binary [default: /usr/local/bin/flynn-init]
--log-dir=DIR directory to store job logs [default: /var/log/flynn]
--discovery=TOKEN join cluster with discovery token
--peer-ips=IPLIST join existing cluster using IPs
--bridge-name=NAME network bridge name [default: flynnbr0]
--no-resurrect disable cluster resurrection
--max-job-concurrency=NUM maximum number of jobs to start concurrently
--partitions=PARTITIONS specify resource partitions for host [default: system=cpu_shares:4096 background=cpu_shares:4096 user=cpu_shares:8192]
`)
}
func main() {
// when starting a container with libcontainer, we first exec the
// current binary with libcontainer-init as the first argument,
// which triggers the following code to initialise the container
// environment (namespaces, network etc.) then exec containerinit
if len(os.Args) > 1 && os.Args[1] == "libcontainer-init" {
runtime.GOMAXPROCS(1)
runtime.LockOSThread()
factory, _ := libcontainer.New("")
if err := factory.StartInitialization(); err != nil {
log.Fatal(err)
}
}
defer shutdown.Exit()
usage := `usage: flynn-host [-h|--help] [--version] <command> [<args>...]
Options:
-h, --help Show this message
--version Show current version
Commands:
help Show usage for a specific command
init Create cluster configuration for daemon
daemon Start the daemon
update Update Flynn components
download Download container images
bootstrap Bootstrap layer 1
inspect Get low-level information about a job
log Get the logs of a job
ps List jobs
stop Stop running jobs
signal Signal a job
destroy-volumes Destroys the local volume database
collect-debug-info Collect debug information into an anonymous gist or tarball
list Lists ID and IP of each host
version Show current version
fix Fix a broken cluster
tags Manage flynn-host daemon tags
discover Return low-level information about a service
See 'flynn-host help <command>' for more information on a specific command.
`
args, _ := docopt.Parse(usage, nil, true, version.String(), true)
cmd := args.String["<command>"]
cmdArgs := args.All["<args>"].([]string)
if cmd == "help" {
if len(cmdArgs) == 0 { // `flynn help`
fmt.Println(usage)
return
} else { // `flynn help <command>`
cmd = cmdArgs[0]
cmdArgs = []string{"--help"}
}
}
if cmd == "daemon" {
// merge in args and env from config file, if available
var c *config.Config
if n := os.Getenv("FLYNN_HOST_CONFIG"); n != "" {
var err error
c, err = config.Open(n)
if err != nil {
shutdown.Fatalf("error opening config file %s: %s", n, err)
}
} else {
var err error
c, err = config.Open(configFile)
if err != nil && !os.IsNotExist(err) {
shutdown.Fatalf("error opening config file %s: %s", configFile, err)
}
if c == nil {
c = &config.Config{}
}
}
cmdArgs = append(cmdArgs, c.Args...)
for k, v := range c.Env {
os.Setenv(k, v)
}
}
if err := cli.Run(cmd, cmdArgs); err != nil {
if err == cli.ErrInvalidCommand {
fmt.Printf("ERROR: %q is not a valid command\n\n", cmd)
fmt.Println(usage)
shutdown.ExitWithCode(1)
} else if _, ok := err.(cli.ErrAlreadyLogged); ok {
shutdown.ExitWithCode(1)
}
shutdown.Fatal(err)
}
}
func runDaemon(args *docopt.Args) {
hostname, _ := os.Hostname()
httpPort := args.String["--http-port"]
externalIP := args.String["--external-ip"]
listenIP := args.String["--listen-ip"]
stateFile := args.String["--state"]
hostID := args.String["--id"]
tags := parseTagArgs(args.String["--tags"])
force := args.Bool["--force"]
volPath := args.String["--volpath"]
volProvider := args.String["--vol-provider"]
backendName := args.String["--backend"]
flynnInit := args.String["--flynn-init"]
logDir := args.String["--log-dir"]
discoveryToken := args.String["--discovery"]
bridgeName := args.String["--bridge-name"]
logger, err := setupLogger(logDir)
if err != nil {
shutdown.Fatalf("error setting up logger: %s", err)
}
var peerIPs []string
if args.String["--peer-ips"] != "" {
peerIPs = strings.Split(args.String["--peer-ips"], ",")
}
if hostID == "" {
hostID = strings.Replace(hostname, "-", "", -1)
}
var maxJobConcurrency uint64 = 4
if m, err := strconv.ParseUint(args.String["--max-job-concurrency"], 10, 64); err == nil {
maxJobConcurrency = m
}
var partitionCGroups = make(map[string]int64) // name -> cpu shares
for _, p := range strings.Split(args.String["--partitions"], " ") {
nameShares := strings.Split(p, "=cpu_shares:")
if len(nameShares) != 2 {
shutdown.Fatalf("invalid partition specifier: %q", p)
}
shares, err := strconv.ParseInt(nameShares[1], 10, 64)
if err != nil || shares < 2 {
shutdown.Fatalf("invalid cpu shares specifier: %q", shares)
}
partitionCGroups[nameShares[0]] = shares
}
for _, s := range []string{"user", "system", "background"} {
if _, ok := partitionCGroups[s]; !ok {
shutdown.Fatalf("missing mandatory resource partition: %s", s)
}
}
log := logger.New("fn", "runDaemon", "host.id", hostID)
log.Info("starting daemon")
log.Info("validating host ID")
if strings.Contains(hostID, "-") {
shutdown.Fatal("host id must not contain dashes")
}
if externalIP == "" {
log.Info("detecting external IP")
var err error
externalIP, err = config.DefaultExternalIP()
if err != nil {
log.Error("error detecting external IP", "err", err)
shutdown.Fatal(err)
}
log.Info("using external IP " + externalIP)
}
publishAddr := net.JoinHostPort(externalIP, httpPort)
if discoveryToken != "" {
// TODO: retry
log.Info("registering with cluster discovery service", "token", discoveryToken, "addr", publishAddr, "name", hostID)
discoveryID, err := discovery.RegisterInstance(discovery.Info{
ClusterURL: discoveryToken,
InstanceURL: "http://" + publishAddr,
Name: hostID,
})
if err != nil {
log.Error("error registering with cluster discovery service", "err", err)
shutdown.Fatal(err)
}
log.Info("registered with cluster discovery service", "id", discoveryID)
}
state := NewState(hostID, stateFile)
shutdown.BeforeExit(func() { state.CloseDB() })
log.Info("initializing volume manager", "provider", volProvider)
var newVolProvider func() (volume.Provider, error)
switch volProvider {
case "zfs":
newVolProvider = func() (volume.Provider, error) {
// use a zpool backing file size of either 70% of the device on which
// volumes will reside, or 100GB if that can't be determined.
log.Info("determining ZFS zpool size")
var size int64
var dev syscall.Statfs_t
if err := syscall.Statfs(volPath, &dev); err == nil {
size = (dev.Bsize * int64(dev.Blocks) * 7) / 10
} else {
size = 100000000000
}
log.Info(fmt.Sprintf("using ZFS zpool size %d", size))
return zfsVolume.NewProvider(&zfsVolume.ProviderConfig{
DatasetName: "flynn-default",
Make: &zfsVolume.MakeDev{
BackingFilename: filepath.Join(volPath, "zfs/vdev/flynn-default-zpool.vdev"),
Size: size,
},
WorkingDir: filepath.Join(volPath, "zfs"),
})
}
case "mock":
newVolProvider = func() (volume.Provider, error) { return nil, nil }
default:
shutdown.Fatalf("unknown volume provider: %q", volProvider)
}
vman := volumemanager.New(
filepath.Join(volPath, "volumes.bolt"),
newVolProvider,
)
shutdown.BeforeExit(func() { vman.CloseDB() })
mux := logmux.New(hostID, logDir, logger.New("host.id", hostID, "component", "logmux"))
log.Info("initializing job backend", "type", backendName)
var backend Backend
switch backendName {
case "libcontainer":
backend, err = NewLibcontainerBackend(state, vman, bridgeName, flynnInit, mux, partitionCGroups, logger.New("host.id", hostID, "component", "backend", "backend", "libcontainer"))
case "mock":
backend = MockBackend{}
default:
shutdown.Fatalf("unknown backend %q", backendName)
}
if err != nil {
shutdown.Fatal(err)
}
backend.SetDefaultEnv("EXTERNAL_IP", externalIP)
backend.SetDefaultEnv("LISTEN_IP", listenIP)
var buffers host.LogBuffers
discoverdManager := NewDiscoverdManager(backend, mux, hostID, publishAddr, tags)
publishURL := "http://" + publishAddr
host := &Host{
id: hostID,
url: publishURL,
status: &host.HostStatus{
ID: hostID,
PID: os.Getpid(),
URL: publishURL,
Tags: tags,
Version: version.String(),
},
state: state,
backend: backend,
vman: vman,
discMan: discoverdManager,
log: logger.New("host.id", hostID),
maxJobConcurrency: maxJobConcurrency,
}
backend.SetHost(host)
// restore the host status if set in the environment
if statusEnv := os.Getenv("FLYNN_HOST_STATUS"); statusEnv != "" {
log.Info("restoring host status from parent")
if err := json.Unmarshal([]byte(statusEnv), &host.status); err != nil {
log.Error("error restoring host status from parent", "err", err)
shutdown.Fatal(err)
}
pid := os.Getpid()
log.Info("setting status PID", "pid", pid)
host.status.PID = pid
// keep the same tags as the parent
discoverdManager.UpdateTags(host.status.Tags)
}
log.Info("creating HTTP listener")
l, err := newHTTPListener(net.JoinHostPort(listenIP, httpPort))
if err != nil {
log.Error("error creating HTTP listener", "err", err)
shutdown.Fatal(err)
}
host.listener = l
shutdown.BeforeExit(func() { host.Close() })
// if we have a control socket FD, wait for a "resume" message before
// opening state DBs and serving requests.
var controlFD int
if fdEnv := os.Getenv("FLYNN_CONTROL_FD"); fdEnv != "" {
log.Info("parsing control socket file descriptor")
controlFD, err = strconv.Atoi(fdEnv)
if err != nil {
log.Error("error parsing control socket file descriptor", "err", err)
shutdown.Fatal(err)
}
log.Info("waiting for resume message from parent")
msg := make([]byte, len(ControlMsgResume))
if _, err := syscall.Read(controlFD, msg); err != nil {
log.Error("error waiting for resume message from parent", "err", err)
shutdown.Fatal(err)
}
log.Info("validating resume message")
if !bytes.Equal(msg, ControlMsgResume) {
log.Error(fmt.Sprintf("unexpected resume message from parent: %v", msg))
shutdown.ExitWithCode(1)
}
log.Info("receiving log buffers from parent")
if err := json.NewDecoder(&controlSock{controlFD}).Decode(&buffers); err != nil {
log.Error("error receiving log buffers from parent", "err", err)
shutdown.Fatal(err)
}
}
log.Info("opening state databases")
if err := host.OpenDBs(); err != nil {
log.Error("error opening state databases", "err", err)
shutdown.Fatal(err)
}
// stopJobs stops all jobs, leaving discoverd until the end so other
// jobs can unregister themselves on shutdown.
stopJobs := func() (err error) {
var except []string
host.statusMtx.RLock()
if host.status.Discoverd != nil && host.status.Discoverd.JobID != "" {
except = []string{host.status.Discoverd.JobID}
}
host.statusMtx.RUnlock()
log.Info("stopping all jobs except discoverd")
if err := backend.Cleanup(except); err != nil {
log.Error("error stopping all jobs except discoverd", "err", err)
return err
}
for _, id := range except {
log.Info("stopping discoverd")
if e := backend.Stop(id); e != nil {
log.Error("error stopping discoverd", "err", err)
err = e
}
}
return
}
log.Info("restoring state")
resurrect, err := state.Restore(backend, buffers)
if err != nil {
log.Error("error restoring state", "err", err)
shutdown.Fatal(err)
}
shutdown.BeforeExit(func() {
// close discoverd before stopping jobs so we can unregister first
log.Info("unregistering with service discovery")
if err := discoverdManager.Close(); err != nil {
log.Error("error unregistering with service discovery", "err", err)
}
stopJobs()
})
log.Info("serving HTTP requests")
host.ServeHTTP()
if controlFD > 0 {
// now that we are serving requests, send an "ok" message to the parent
log.Info("sending ok message to parent")
if _, err := syscall.Write(controlFD, ControlMsgOK); err != nil {
log.Error("error sending ok message to parent", "err", err)
shutdown.Fatal(err)
}
log.Info("closing control socket")
if err := syscall.Close(controlFD); err != nil {
log.Error("error closing control socket", "err", err)
}
}
if force {
log.Info("forcibly stopping existing jobs")
if err := stopJobs(); err != nil {
log.Error("error forcibly stopping existing jobs", "err", err)
shutdown.Fatal(err)
}
}
if discoveryToken != "" {
log.Info("getting cluster peer IPs")
instances, err := discovery.GetCluster(discoveryToken)
if err != nil {
// TODO(titanous): retry?
log.Error("error getting discovery cluster", "err", err)
shutdown.Fatal(err)
}
peerIPs = make([]string, 0, len(instances))
for _, inst := range instances {
u, err := url.Parse(inst.URL)
if err != nil {
continue
}
ip, _, err := net.SplitHostPort(u.Host)
if err != nil || ip == externalIP {
continue
}
peerIPs = append(peerIPs, ip)
}
log.Info("got cluster peer IPs", "peers", peerIPs)
}
log.Info("connecting to cluster peers")
if err := discoverdManager.ConnectPeer(peerIPs); err != nil {
log.Info("no cluster peers available")
}
if !args.Bool["--no-resurrect"] {
log.Info("resurrecting jobs")
resurrect()
}
monitor := NewMonitor(host.discMan, externalIP, logger)
shutdown.BeforeExit(func() { monitor.Shutdown() })
go monitor.Run()
log.Info("blocking main goroutine")
<-make(chan struct{})
}
func parseTagArgs(args string) map[string]string {
tags := make(map[string]string)
for _, s := range strings.Split(args, ",") {
keyVal := strings.SplitN(s, "=", 2)
if len(keyVal) == 1 && keyVal[0] != "" {
tags[keyVal[0]] = "true"
} else if len(keyVal) == 2 {
tags[keyVal[0]] = keyVal[1]
}
}
return tags
}
func setupLogger(logDir string) (log15.Logger, error) {
if err := os.MkdirAll(logDir, 0755); err != nil {
return nil, err
}
path := filepath.Join(logDir, "flynn-host.log")
handler, err := log15.FileHandler(path, log15.LogfmtFormat())
if err != nil {
return nil, err
}
log15.Root().SetHandler(handler)
return log15.New("app", "host", "pid", os.Getpid()), nil
}