// SwitchStream returns nil errors every time there could be a new graph.
func (obj *GAPI) SwitchStream() chan error {
if obj.data.NoWatch {
return nil
}
ch := make(chan error)
obj.wg.Add(1)
go func() {
defer obj.wg.Done()
defer close(ch) // this will run before the obj.wg.Done()
if !obj.initialized {
ch <- fmt.Errorf("yamlgraph: GAPI is not initialized")
return
}
configWatcher := recwatch.NewConfigWatcher()
configChan := configWatcher.ConfigWatch(*obj.File) // simple
for {
select {
case err, ok := <-configChan: // returns nil events on ok!
if !ok { // the channel closed!
return
}
log.Printf("yamlgraph: Generating new graph...")
ch <- err // trigger a run
if err != nil {
return
}
case <-obj.closeChan:
return
}
}
}()
return ch
}
// Run is the main execution entrypoint to run mgmt.
func (obj *Main) Run() error {
var start = time.Now().UnixNano()
var flags int
if obj.DEBUG || true { // TODO: remove || true
flags = log.LstdFlags | log.Lshortfile
}
flags = (flags - log.Ldate) // remove the date for now
log.SetFlags(flags)
// un-hijack from capnslog...
log.SetOutput(os.Stderr)
if obj.VERBOSE {
capnslog.SetFormatter(capnslog.NewLogFormatter(os.Stderr, "(etcd) ", flags))
} else {
capnslog.SetFormatter(capnslog.NewNilFormatter())
}
log.Printf("This is: %s, version: %s", obj.Program, obj.Version)
log.Printf("Main: Start: %v", start)
hostname, err := os.Hostname() // a sensible default
// allow passing in the hostname, instead of using the system setting
if h := obj.Hostname; h != nil && *h != "" { // override by cli
hostname = *h
} else if err != nil {
return errwrap.Wrapf(err, "Can't get default hostname!")
}
if hostname == "" { // safety check
return fmt.Errorf("Hostname cannot be empty!")
}
var prefix = fmt.Sprintf("/var/lib/%s/", obj.Program) // default prefix
if p := obj.Prefix; p != nil {
prefix = *p
}
// make sure the working directory prefix exists
if obj.TmpPrefix || os.MkdirAll(prefix, 0770) != nil {
if obj.TmpPrefix || obj.AllowTmpPrefix {
var err error
if prefix, err = ioutil.TempDir("", obj.Program+"-"+hostname+"-"); err != nil {
return fmt.Errorf("Main: Error: Can't create temporary prefix!")
}
log.Println("Main: Warning: Working prefix directory is temporary!")
} else {
return fmt.Errorf("Main: Error: Can't create prefix!")
}
}
log.Printf("Main: Working prefix is: %s", prefix)
var wg sync.WaitGroup
var G, oldGraph *pgraph.Graph
// exit after `max-runtime` seconds for no reason at all...
if i := obj.MaxRuntime; i > 0 {
go func() {
time.Sleep(time.Duration(i) * time.Second)
obj.Exit(nil)
}()
}
// setup converger
converger := converger.NewConverger(
obj.ConvergedTimeout,
nil, // stateFn gets added in by EmbdEtcd
)
go converger.Loop(true) // main loop for converger, true to start paused
// embedded etcd
if len(obj.seeds) == 0 {
log.Printf("Main: Seeds: No seeds specified!")
} else {
log.Printf("Main: Seeds(%d): %v", len(obj.seeds), obj.seeds)
}
EmbdEtcd := etcd.NewEmbdEtcd(
hostname,
obj.seeds,
obj.clientURLs,
obj.serverURLs,
obj.NoServer,
obj.idealClusterSize,
prefix,
converger,
)
if EmbdEtcd == nil {
// TODO: verify EmbdEtcd is not nil below...
obj.Exit(fmt.Errorf("Main: Etcd: Creation failed!"))
} else if err := EmbdEtcd.Startup(); err != nil { // startup (returns when etcd main loop is running)
obj.Exit(fmt.Errorf("Main: Etcd: Startup failed: %v", err))
}
convergerStateFn := func(b bool) error {
// exit if we are using the converged timeout and we are the
// root node. otherwise, if we are a child node in a remote
// execution hierarchy, we should only notify our converged
// state and wait for the parent to trigger the exit.
if t := obj.ConvergedTimeout; obj.Depth == 0 && t >= 0 {
if b {
log.Printf("Converged for %d seconds, exiting!", t)
obj.Exit(nil) // trigger an exit!
}
return nil
}
// send our individual state into etcd for others to see
return etcd.EtcdSetHostnameConverged(EmbdEtcd, hostname, b) // TODO: what should happen on error?
}
if EmbdEtcd != nil {
converger.SetStateFn(convergerStateFn)
}
var gapiChan chan error // stream events are nil errors
if obj.GAPI != nil {
data := gapi.Data{
Hostname: hostname,
EmbdEtcd: EmbdEtcd,
Noop: obj.Noop,
NoWatch: obj.NoWatch,
}
if err := obj.GAPI.Init(data); err != nil {
obj.Exit(fmt.Errorf("Main: GAPI: Init failed: %v", err))
} else if !obj.NoWatch {
gapiChan = obj.GAPI.SwitchStream() // stream of graph switch events!
}
}
exitchan := make(chan struct{}) // exit on close
go func() {
startChan := make(chan struct{}) // start signal
go func() { startChan <- struct{}{} }()
log.Println("Etcd: Starting...")
etcdChan := etcd.EtcdWatch(EmbdEtcd)
first := true // first loop or not
for {
log.Println("Main: Waiting...")
select {
case <-startChan: // kick the loop once at start
// pass
case b := <-etcdChan:
if !b { // ignore the message
continue
}
// everything else passes through to cause a compile!
case err, ok := <-gapiChan:
if !ok { // channel closed
if obj.DEBUG {
log.Printf("Main: GAPI exited")
}
gapiChan = nil // disable it
continue
}
if err != nil {
obj.Exit(err) // trigger exit
continue
//return // TODO: return or wait for exitchan?
}
if obj.NoWatch { // extra safety for bad GAPI's
log.Printf("Main: GAPI stream should be quiet with NoWatch!") // fix the GAPI!
continue // no stream events should be sent
}
case <-exitchan:
return
}
if obj.GAPI == nil {
log.Printf("Config: GAPI is empty!")
continue
}
// we need the vertices to be paused to work on them, so
// run graph vertex LOCK...
if !first { // TODO: we can flatten this check out I think
converger.Pause() // FIXME: add sync wait?
G.Pause() // sync
//G.UnGroup() // FIXME: implement me if needed!
}
// make the graph from yaml, lib, puppet->yaml, or dsl!
newGraph, err := obj.GAPI.Graph() // generate graph!
if err != nil {
log.Printf("Config: Error creating new graph: %v", err)
// unpause!
if !first {
G.Start(&wg, first) // sync
converger.Start() // after G.Start()
}
continue
}
// apply the global noop parameter if requested
if obj.Noop {
for _, m := range newGraph.GraphMetas() {
m.Noop = obj.Noop
}
}
// FIXME: make sure we "UnGroup()" any semi-destructive
// changes to the resources so our efficient GraphSync
// will be able to re-use and cmp to the old graph.
newFullGraph, err := newGraph.GraphSync(oldGraph)
if err != nil {
log.Printf("Config: Error running graph sync: %v", err)
// unpause!
if !first {
G.Start(&wg, first) // sync
converger.Start() // after G.Start()
}
continue
}
oldGraph = newFullGraph // save old graph
G = oldGraph.Copy() // copy to active graph
G.AutoEdges() // add autoedges; modifies the graph
G.AutoGroup() // run autogroup; modifies the graph
// TODO: do we want to do a transitive reduction?
log.Printf("Graph: %v", G) // show graph
if obj.GraphvizFilter != "" {
if err := G.ExecGraphviz(obj.GraphvizFilter, obj.Graphviz); err != nil {
log.Printf("Graphviz: %v", err)
} else {
log.Printf("Graphviz: Successfully generated graph!")
}
}
G.AssociateData(converger)
// G.Start(...) needs to be synchronous or wait,
// because if half of the nodes are started and
// some are not ready yet and the EtcdWatch
// loops, we'll cause G.Pause(...) before we
// even got going, thus causing nil pointer errors
G.Start(&wg, first) // sync
converger.Start() // after G.Start()
first = false
}
}()
configWatcher := recwatch.NewConfigWatcher()
events := configWatcher.Events()
if !obj.NoWatch {
configWatcher.Add(obj.Remotes...) // add all the files...
} else {
events = nil // signal that no-watch is true
}
go func() {
select {
case err := <-configWatcher.Error():
obj.Exit(err) // trigger an exit!
case <-exitchan:
return
}
}()
// initialize the add watcher, which calls the f callback on map changes
convergerCb := func(f func(map[string]bool) error) (func(), error) {
return etcd.EtcdAddHostnameConvergedWatcher(EmbdEtcd, f)
}
// build remotes struct for remote ssh
remotes := remote.NewRemotes(
EmbdEtcd.LocalhostClientURLs().StringSlice(),
[]string{etcd.DefaultClientURL},
obj.Noop,
obj.Remotes, // list of files
events, // watch for file changes
obj.CConns,
obj.AllowInteractive,
obj.SSHPrivIDRsa,
!obj.NoCaching,
obj.Depth,
prefix,
converger,
convergerCb,
obj.Program,
)
// TODO: is there any benefit to running the remotes above in the loop?
// wait for etcd to be running before we remote in, which we do above!
go remotes.Run()
if obj.GAPI == nil {
converger.Start() // better start this for empty graphs
}
log.Println("Main: Running...")
reterr := <-obj.exit // wait for exit signal
log.Println("Destroy...")
if obj.GAPI != nil {
if err := obj.GAPI.Close(); err != nil {
err = errwrap.Wrapf(err, "GAPI closed poorly!")
reterr = multierr.Append(reterr, err) // list of errors
}
}
configWatcher.Close() // stop sending file changes to remotes
if err := remotes.Exit(); err != nil { // tell all the remote connections to shutdown; waits!
err = errwrap.Wrapf(err, "Remote exited poorly!")
reterr = multierr.Append(reterr, err) // list of errors
}
G.Exit() // tell all the children to exit
// tell inner main loop to exit
close(exitchan)
// cleanup etcd main loop last so it can process everything first
if err := EmbdEtcd.Destroy(); err != nil { // shutdown and cleanup etcd
err = errwrap.Wrapf(err, "Etcd exited poorly!")
reterr = multierr.Append(reterr, err) // list of errors
}
if obj.DEBUG {
log.Printf("Main: Graph: %v", G)
}
wg.Wait() // wait for primary go routines to exit
// TODO: wait for each vertex to exit...
log.Println("Goodbye!")
return reterr
}