Refactor Daemon into Children and DaemonRestarter into Daemon

go/cmd/entrypoint/admin.go

@@ -166,25 +166,33 @@ var subCmdAdminCreateNetwork = subCmd{
 			return fmt.Errorf("merging daemon config into bootstrap data: %w", err)
 		}
 
-		daemonInst, err := daemon.New(
+		children, err := daemon.NewChildren(
 			ctx,
 			logger.WithNamespace("daemon"),
 			daemonConfig,
 			hostBootstrap,
 			envBinDirPath,
 			&daemon.Opts{
-				// SkipHostBootstrapPush is required, because the global bucket
-				// hasn't actually been initialized yet, so there's nowhere to
-				// push to.
-				SkipHostBootstrapPush: true,
-
 				// NOTE both stdout and stderr are sent to stderr, so that the
 				// user can pipe the resulting admin.json to stdout.
 				Stdout: os.Stderr,
 			},
 		)
 		if err != nil {
-			return fmt.Errorf("initializing daemon: %w", err)
+			return fmt.Errorf("initializing children: %w", err)
+		}
+		defer func() {
+			logger.Info(ctx, "Shutting down child processes")
+			if err := children.Shutdown(); err != nil {
+				logger.Error(ctx, "Failed to shut down children cleanly, there may be zombie children leftover", err)
+			}
+		}()
+
+		logger.Info(ctx, "Applying garage layout")
+		if err := daemon.GarageApplyLayout(
+			ctx, logger, hostBootstrap, daemonConfig,
+		); err != nil {
+			return fmt.Errorf("applying garage layout: %w", err)
 		}
 
 		logger.Info(ctx, "initializing garage shared global bucket")
@@ -199,10 +207,6 @@ var subCmdAdminCreateNetwork = subCmd{
 			return fmt.Errorf("initializing garage shared global bucket: %w", err)
 		}
 
-		if err := daemonInst.Shutdown(); err != nil {
-			return fmt.Errorf("shutting down daemon: %w (this can mean there are zombie children leftover)", err)
-		}
-
 		hostBootstrap.Garage.GlobalBucketS3APICredentials = garageGlobalBucketCreds
 
 		// rewrite the bootstrap now that the global bucket creds have been
@@ -211,7 +215,7 @@ var subCmdAdminCreateNetwork = subCmd{
 			return fmt.Errorf("writing bootstrap file: %w", err)
 		}
 
-		logger.Info(ctx, "cluster initialized successfully, writing admin.json to stdout")
+		logger.Info(ctx, "Network initialized successfully, writing admin.json to stdout")
 
 		adm := admin.Admin{
 			CreationParams: adminCreationParams,

go/cmd/entrypoint/daemon.go

@@ -127,7 +127,7 @@ var subCmdDaemon = subCmd{
 			return fmt.Errorf("merging daemon config into bootstrap data: %w", err)
 		}
 
-		daemonInst := daemon.NewDaemonRestarter(
+		daemonInst := daemon.NewDaemon(
 			logger, daemonConfig, envBinDirPath, hostBootstrap, nil,
 		)
 		defer func() {

go/daemon/child_garage.go

@@ -39,9 +39,14 @@ func NewGarageAdminClient(
 	)
 }
 
-func (d *daemon) waitForGarage(ctx context.Context) error {
+func waitForGarage(
+	ctx context.Context,
+	logger *mlog.Logger,
+	daemonConfig Config,
+	hostBootstrap bootstrap.Bootstrap,
+) error {
 
-	allocs := d.config.Storage.Allocations
+	allocs := daemonConfig.Storage.Allocations
 
 	// if this host doesn't have any allocations specified then fall back to
 	// waiting for nebula
@@ -49,23 +54,23 @@ func (d *daemon) waitForGarage(ctx context.Context) error {
 		return nil
 	}
 
-	adminClientLogger := garageAdminClientLogger(d.logger)
+	adminClientLogger := garageAdminClientLogger(logger)
 
 	for _, alloc := range allocs {
 
 		adminAddr := net.JoinHostPort(
-			d.hostBootstrap.ThisHost().IP().String(),
+			hostBootstrap.ThisHost().IP().String(),
 			strconv.Itoa(alloc.AdminPort),
 		)
 
 		adminClient := garage.NewAdminClient(
 			adminClientLogger,
 			adminAddr,
-			d.hostBootstrap.Garage.AdminToken,
+			hostBootstrap.Garage.AdminToken,
 		)
 
 		ctx := mctx.Annotate(ctx, "garageAdminAddr", adminAddr)
-		d.logger.Debug(ctx, "waiting for garage instance to start")
+		logger.Debug(ctx, "waiting for garage instance to start")
 
 		if err := adminClient.Wait(ctx); err != nil {
 			return fmt.Errorf("waiting for garage instance %q to start up: %w", adminAddr, err)
@@ -139,9 +144,10 @@ func garageWriteChildConfig(
 }
 
 func garagePmuxProcConfigs(
+	logger *mlog.Logger,
 	runtimeDirPath, binDirPath string,
-	hostBootstrap bootstrap.Bootstrap,
 	daemonConfig Config,
+	hostBootstrap bootstrap.Bootstrap,
 ) (
 	[]pmuxlib.ProcessConfig, error,
 ) {
@@ -162,7 +168,7 @@ func garagePmuxProcConfigs(
 			Cmd:  filepath.Join(binDirPath, "garage"),
 			Args: []string{"-c", childConfigPath, "server"},
 			StartAfterFunc: func(ctx context.Context) error {
-				return waitForNebula(ctx, hostBootstrap)
+				return waitForNebula(ctx, logger, hostBootstrap)
 			},
 		})
 	}
@@ -170,7 +176,9 @@ func garagePmuxProcConfigs(
 	return pmuxProcConfigs, nil
 }
 
-func garageApplyLayout(
+// TODO don't expose this publicly once cluster creation is done via Daemon
+// interface.
+func GarageApplyLayout(
 	ctx context.Context,
 	logger *mlog.Logger,
 	hostBootstrap bootstrap.Bootstrap,

go/daemon/child_nebula.go

@@ -9,6 +9,8 @@ import (
 	"path/filepath"
 
 	"code.betamike.com/micropelago/pmux/pmuxlib"
+	"dev.mediocregopher.com/mediocre-go-lib.git/mctx"
+	"dev.mediocregopher.com/mediocre-go-lib.git/mlog"
 	"github.com/slackhq/nebula/cert"
 )
 
@@ -17,28 +19,37 @@ import (
 // its source. If this succeeds we can assume that at the very least the nebula
 // interface has been initialized.
 func waitForNebula(
-	ctx context.Context, hostBootstrap bootstrap.Bootstrap,
+	ctx context.Context, logger *mlog.Logger, hostBootstrap bootstrap.Bootstrap,
 ) error {
+	var (
+		ip       = hostBootstrap.ThisHost().IP()
+		lUDPAddr = &net.UDPAddr{IP: ip, Port: 0}
+		rUDPAddr = &net.UDPAddr{IP: ip, Port: 45535}
+	)
 
-	ip := hostBootstrap.ThisHost().IP()
+	ctx = mctx.Annotate(ctx, "lUDPAddr", lUDPAddr, "rUDPAddr", rUDPAddr)
 
-	lUdpAddr := &net.UDPAddr{IP: ip, Port: 0}
+	until(
-	rUdpAddr := &net.UDPAddr{IP: ip, Port: 45535}
+		ctx,
-
+		logger,
-	return until(ctx, func(context.Context) error {
+		"Creating UDP socket from nebula addr",
-		conn, err := net.DialUDP("udp", lUdpAddr, rUdpAddr)
+		func(context.Context) error {
+			conn, err := net.DialUDP("udp", lUDPAddr, rUDPAddr)
 			if err != nil {
 				return err
 			}
 			conn.Close()
 			return nil
-	})
+		},
+	)
+
+	return ctx.Err()
 }
 
 func nebulaPmuxProcConfig(
 	runtimeDirPath, binDirPath string,
-	hostBootstrap bootstrap.Bootstrap,
 	daemonConfig Config,
+	hostBootstrap bootstrap.Bootstrap,
 ) (
 	pmuxlib.ProcessConfig, error,
 ) {

go/daemon/child_pmux.go

@@ -3,26 +3,29 @@ package daemon
 import (
 	"context"
 	"fmt"
+	"isle/bootstrap"
 
 	"code.betamike.com/micropelago/pmux/pmuxlib"
 )
 
-func (d *daemon) newPmuxConfig() (pmuxlib.Config, error) {
+func (c *Children) newPmuxConfig(
+	binDirPath string, daemonConfig Config, hostBootstrap bootstrap.Bootstrap,
+) (pmuxlib.Config, error) {
 	nebulaPmuxProcConfig, err := nebulaPmuxProcConfig(
-		d.opts.EnvVars.RuntimeDirPath,
+		c.opts.EnvVars.RuntimeDirPath,
-		d.binDirPath,
+		binDirPath,
-		d.hostBootstrap,
+		daemonConfig,
-		d.config,
+		hostBootstrap,
 	)
 	if err != nil {
 		return pmuxlib.Config{}, fmt.Errorf("generating nebula config: %w", err)
 	}
 
 	dnsmasqPmuxProcConfig, err := dnsmasqPmuxProcConfig(
-		d.opts.EnvVars.RuntimeDirPath,
+		c.opts.EnvVars.RuntimeDirPath,
-		d.binDirPath,
+		binDirPath,
-		d.hostBootstrap,
+		hostBootstrap,
-		d.config,
+		daemonConfig,
 	)
 	if err != nil {
 		return pmuxlib.Config{}, fmt.Errorf(
@@ -31,7 +34,11 @@ func (d *daemon) newPmuxConfig() (pmuxlib.Config, error) {
 	}
 
 	garagePmuxProcConfigs, err := garagePmuxProcConfigs(
-		d.opts.EnvVars.RuntimeDirPath, d.binDirPath, d.hostBootstrap, d.config,
+		c.logger,
+		c.opts.EnvVars.RuntimeDirPath,
+		binDirPath,
+		daemonConfig,
+		hostBootstrap,
 	)
 	if err != nil {
 		return pmuxlib.Config{}, fmt.Errorf(
@@ -50,46 +57,21 @@ func (d *daemon) newPmuxConfig() (pmuxlib.Config, error) {
 	}, nil
 }
 
-func (d *daemon) postPmuxInit(ctx context.Context) error {
+func (c *Children) postPmuxInit(
-	d.logger.Info(ctx, "waiting for nebula VPN to come online")
+	ctx context.Context,
-	if err := waitForNebula(ctx, d.hostBootstrap); err != nil {
+	daemonConfig Config,
+	hostBootstrap bootstrap.Bootstrap,
+) error {
+	c.logger.Info(ctx, "Waiting for nebula VPN to come online")
+	if err := waitForNebula(ctx, c.logger, hostBootstrap); err != nil {
 		return fmt.Errorf("waiting for nebula to start: %w", err)
 	}
 
-	d.logger.Info(ctx, "waiting for garage instances to come online")
+	c.logger.Info(ctx, "Waiting for garage instances to come online")
-	if err := d.waitForGarage(ctx); err != nil {
+	err := waitForGarage(ctx, c.logger, daemonConfig, hostBootstrap)
+	if err != nil {
 		return fmt.Errorf("waiting for garage to start: %w", err)
 	}
 
-	if len(d.config.Storage.Allocations) > 0 {
-
-		err := until(ctx, func(ctx context.Context) error {
-			err := garageApplyLayout(ctx, d.logger, d.hostBootstrap, d.config)
-			if err != nil {
-				d.logger.Error(ctx, "applying garage layout", err)
-				return err
-			}
-
-			return nil
-		})
-
-		if err != nil {
-			return fmt.Errorf("applying garage layout: %w", err)
-		}
-	}
-
-	if !d.opts.SkipHostBootstrapPush {
-		if err := until(ctx, func(ctx context.Context) error {
-			if err := d.putGarageBoostrapHost(ctx); err != nil {
-				d.logger.Error(ctx, "updating host info in garage", err)
-				return err
-			}
-
-			return nil
-		}); err != nil {
-			return fmt.Errorf("updating host info in garage: %w", err)
-		}
-	}
-
 	return nil
 }

go/daemon/children.go

@@ -0,0 +1,86 @@
+package daemon
+
+import (
+	"context"
+	"fmt"
+	"isle/bootstrap"
+
+	"code.betamike.com/micropelago/pmux/pmuxlib"
+	"dev.mediocregopher.com/mediocre-go-lib.git/mlog"
+)
+
+// Children manages all child processes of a network. Child processes are
+// comprised of:
+// - nebula
+// - dnsmasq
+// - garage (0 or more, depending on configured storage allocations)
+type Children struct {
+	logger *mlog.Logger
+	opts   Opts
+
+	pmuxCancelFn  context.CancelFunc
+	pmuxStoppedCh chan struct{}
+}
+
+// NewChildren initialized and returns a Children instance. If initialization
+// fails an error is returned.
+func NewChildren(
+	ctx context.Context,
+	logger *mlog.Logger,
+	daemonConfig Config,
+	hostBootstrap bootstrap.Bootstrap,
+	binDirPath string,
+	opts *Opts,
+) (
+	*Children, error,
+) {
+	opts = opts.withDefaults()
+
+	pmuxCtx, pmuxCancelFn := context.WithCancel(context.Background())
+
+	c := &Children{
+		logger:        logger,
+		opts:          *opts,
+		pmuxCancelFn:  pmuxCancelFn,
+		pmuxStoppedCh: make(chan struct{}),
+	}
+
+	pmuxConfig, err := c.newPmuxConfig(binDirPath, daemonConfig, hostBootstrap)
+	if err != nil {
+		return nil, fmt.Errorf("generating pmux config: %w", err)
+	}
+
+	go func() {
+		defer close(c.pmuxStoppedCh)
+		pmuxlib.Run(pmuxCtx, c.opts.Stdout, c.opts.Stderr, pmuxConfig)
+		c.logger.Debug(pmuxCtx, "pmux stopped")
+	}()
+
+	initErr := c.postPmuxInit(ctx, daemonConfig, hostBootstrap)
+	if initErr != nil {
+		logger.Warn(ctx, "failed to initialize Children, shutting down child processes", err)
+		if err := c.Shutdown(); err != nil {
+			panic(fmt.Sprintf(
+				"failed to shut down child processes after initialization"+
+					" error, there may be zombie children leftover."+
+					" Original error: %v",
+				initErr,
+			))
+		}
+
+		return nil, initErr
+	}
+
+	return c, nil
+}
+
+// Shutdown blocks until all child processes have gracefully shut themselves
+// down.
+//
+// If this returns an error then it's possible that child processes are
+// still running and are no longer managed.
+func (c *Children) Shutdown() error {
+	c.pmuxCancelFn()
+	<-c.pmuxStoppedCh
+	return nil
+}

go/daemon/daemon.go

@@ -1,15 +1,18 @@
 // Package daemon implements the isle daemon, which is a long-running service
-// managing all isle background tasks and sub-processes for a single cluster.
+// managing all isle background tasks and sub-processes for a single network.
 package daemon
 
 import (
+	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"isle/bootstrap"
 	"os"
+	"sync"
+	"time"
 
-	"code.betamike.com/micropelago/pmux/pmuxlib"
 	"dev.mediocregopher.com/mediocre-go-lib.git/mlog"
 )
 
@@ -36,10 +39,6 @@ type Daemon interface {
 // Opts are optional parameters which can be passed in when initializing a new
 // Daemon instance. A nil Opts is equivalent to a zero value.
 type Opts struct {
-	// SkipHostBootstrapPush, if set, will cause the Daemon to not push the
-	// bootstrap to garage upon a successful initialization.
-	SkipHostBootstrapPush bool
-
 	// Stdout and Stderr are what the associated outputs from child processes
 	// will be directed to.
 	Stdout, Stderr io.Writer
@@ -67,73 +66,280 @@ func (o *Opts) withDefaults() *Opts {
 	return o
 }
 
+const (
+	daemonStateInitializing = iota
+	daemonStateOk
+	daemonStateRestarting
+	daemonStateShutdown
+)
+
 type daemon struct {
 	logger        *mlog.Logger
-	config        Config
+	daemonConfig  Config
-	hostBootstrap bootstrap.Bootstrap
+	envBinDirPath string
-	binDirPath    string
+	opts          *Opts
-	opts          Opts
 
-	pmuxCancelFn  context.CancelFunc
+	l             sync.Mutex
-	pmuxStoppedCh chan struct{}
+	state         int
+	children      *Children
+	currBootstrap bootstrap.Bootstrap
+
+	cancelFn  context.CancelFunc
+	stoppedCh chan struct{}
 }
 
-// New initialized and returns a Daemon. If initialization fails an error is
+// NewDaemon initializes and returns a Daemon instance which will manage all
-// returned.
+// child processes and state required by the isle service, as well as an HTTP
-func New(
+// socket over which RPC calls will be served.
-	ctx context.Context,
+//
+// Inner Children instance(s) will be wrapped such that they will be
+// automatically shutdown and re-created whenever there's changes in the network
+// which require the configuration to be changed (e.g. a new nebula lighthouse).
+// During such an inner restart all methods will return ErrRestarting, except
+// Shutdown which will block until the currently executing restart is finished
+// and then shutdown cleanly from there.
+//
+// While still starting up the Daemon for the first time all methods will return
+// ErrInitializing, except Shutdown which will block until initialization is
+// canceled.
+//
+// TODO make daemon smarter, it currently restarts on _any_ change, but
+// it should restart itself only when there's something actually requiring a
+// restart.
+func NewDaemon(
 	logger *mlog.Logger,
-	config Config,
+	daemonConfig Config,
-	hostBootstrap bootstrap.Bootstrap,
+	envBinDirPath string,
-	binDirPath string,
+	currBootstrap bootstrap.Bootstrap,
 	opts *Opts,
-) (
+) Daemon {
-	Daemon, error,
+	ctx, cancelFn := context.WithCancel(context.Background())
-) {
-	opts = opts.withDefaults()
-
-	pmuxCtx, pmuxCancelFn := context.WithCancel(context.Background())
 
 	d := &daemon{
 		logger:        logger,
-		config:        config,
+		daemonConfig:  daemonConfig,
-		hostBootstrap: hostBootstrap,
+		envBinDirPath: envBinDirPath,
-		binDirPath:    binDirPath,
+		opts:          opts.withDefaults(),
-		opts:          *opts,
+		currBootstrap: currBootstrap,
-		pmuxCancelFn:  pmuxCancelFn,
+		cancelFn:      cancelFn,
-		pmuxStoppedCh: make(chan struct{}),
+		stoppedCh:     make(chan struct{}),
-	}
-
-	pmuxConfig, err := d.newPmuxConfig()
-	if err != nil {
-		return nil, fmt.Errorf("generating pmux config: %w", err)
 	}
 
 	go func() {
-		defer close(d.pmuxStoppedCh)
+		d.restartLoop(ctx)
-		pmuxlib.Run(pmuxCtx, d.opts.Stdout, d.opts.Stderr, pmuxConfig)
+		d.logger.Debug(ctx, "DaemonRestarter stopped")
-		d.logger.Debug(pmuxCtx, "pmux stopped")
+		close(d.stoppedCh)
 	}()
 
-	if initErr := d.postPmuxInit(ctx); initErr != nil {
+	return d
-		logger.Warn(ctx, "failed to initialize daemon, shutting down child processes", err)
-		if err := d.Shutdown(); err != nil {
-			panic(fmt.Sprintf(
-				"failed to shut down child processes after initialization"+
-					" error, there may be zombie children leftover."+
-					" Original error: %v",
-				initErr,
-			))
 }
 
-		return nil, initErr
+func withInnerChildren[Res any](
+	d *daemon, fn func(*Children) (Res, error),
+) (Res, error) {
+	var zero Res
+	d.l.Lock()
+	children, state := d.children, d.state
+	d.l.Unlock()
+
+	switch state {
+	case daemonStateInitializing:
+		return zero, ErrInitializing
+	case daemonStateOk:
+		return fn(children)
+	case daemonStateRestarting:
+		return zero, ErrRestarting
+	case daemonStateShutdown:
+		return zero, errors.New("already shutdown")
+	default:
+		panic(fmt.Sprintf("unknown state %d", d.state))
+	}
 }
 
-	return d, nil
+// creates a new bootstrap file using available information from the network. If
+// the new bootstrap file is different than the existing one, the existing one
+// is overwritten and true is returned.
+func (d *daemon) checkBootstrap(
+	ctx context.Context, hostBootstrap bootstrap.Bootstrap,
+) (
+	bootstrap.Bootstrap, bool, error,
+) {
+
+	thisHost := hostBootstrap.ThisHost()
+
+	newHosts, err := d.getGarageBootstrapHosts(ctx)
+	if err != nil {
+		return bootstrap.Bootstrap{}, false, fmt.Errorf("getting hosts from garage: %w", err)
+	}
+
+	// the daemon's view of this host's bootstrap info takes precedence over
+	// whatever is in garage
+	newHosts[thisHost.Name] = thisHost
+
+	newHostsHash, err := bootstrap.HostsHash(newHosts)
+	if err != nil {
+		return bootstrap.Bootstrap{}, false, fmt.Errorf("calculating hash of new hosts: %w", err)
+	}
+
+	currHostsHash, err := bootstrap.HostsHash(hostBootstrap.Hosts)
+	if err != nil {
+		return bootstrap.Bootstrap{}, false, fmt.Errorf("calculating hash of current hosts: %w", err)
+	}
+
+	if bytes.Equal(newHostsHash, currHostsHash) {
+		return hostBootstrap, false, nil
+	}
+
+	hostBootstrap.Hosts = newHosts
+
+	return hostBootstrap, true, nil
+}
+
+// blocks until a new bootstrap is available or context is canceled
+func (d *daemon) watchForChanges(ctx context.Context) bootstrap.Bootstrap {
+
+	ticker := time.NewTicker(3 * time.Minute)
+	defer ticker.Stop()
+
+	for {
+		select {
+
+		case <-ctx.Done():
+			return bootstrap.Bootstrap{}
+
+		case <-ticker.C:
+
+			d.logger.Info(ctx, "Checking for changes to bootstrap")
+
+			newBootstrap, changed, err := d.checkBootstrap(
+				ctx, d.currBootstrap,
+			)
+			if err != nil {
+				d.logger.Error(ctx, "Checking bootstrap for changes failed", err)
+				continue
+			} else if !changed {
+				continue
+			}
+
+			err = writeBootstrapToStateDir(d.opts.EnvVars.StateDirPath, newBootstrap)
+			if err != nil {
+				d.logger.Error(ctx, "Writing new bootstrap to disk failed", err)
+				continue
+			}
+
+			return newBootstrap
+		}
+	}
+}
+
+func (d *daemon) restartLoop(ctx context.Context) {
+	defer func() {
+		d.l.Lock()
+		d.state = daemonStateShutdown
+		children := d.children
+		d.l.Unlock()
+
+		if children != nil {
+			if err := children.Shutdown(); err != nil {
+				d.logger.Fatal(ctx, "Failed to cleanly shutdown daemon children, there may be orphaned child processes", err)
+			}
+		}
+	}()
+
+	wait := func(d time.Duration) bool {
+		select {
+		case <-ctx.Done():
+			return false
+		case <-time.After(d):
+			return true
+		}
+	}
+
+	for {
+		if ctx.Err() != nil {
+			return
+		}
+
+		d.logger.Info(ctx, "Creating new daemon")
+		children, err := NewChildren(
+			ctx,
+			d.logger.WithNamespace("daemon"),
+			d.daemonConfig,
+			d.currBootstrap,
+			d.envBinDirPath,
+			d.opts,
+		)
+		if errors.Is(err, context.Canceled) {
+			return
+		} else if err != nil {
+			d.logger.Error(ctx, "failed to initialize daemon", err)
+			if !wait(1 * time.Second) {
+				return
+			}
+			continue
+		}
+
+		d.l.Lock()
+		d.children = children
+		d.state = daemonStateOk
+		d.l.Unlock()
+
+		if len(d.daemonConfig.Storage.Allocations) > 0 {
+			if !until(
+				ctx,
+				d.logger,
+				"Applying garage layout",
+				func(ctx context.Context) error {
+					return GarageApplyLayout(
+						ctx, d.logger, d.currBootstrap, d.daemonConfig,
+					)
+				},
+			) {
+				return
+			}
+		}
+
+		if !until(
+			ctx,
+			d.logger,
+			"Updating host info in garage",
+			func(ctx context.Context) error {
+				return d.putGarageBoostrapHost(ctx)
+			},
+		) {
+			return
+		}
+
+		newBootstrap := d.watchForChanges(ctx)
+		if ctx.Err() != nil {
+			return
+		}
+
+		d.logger.Info(ctx, "Bootstrap has changed, will restart daemon")
+		d.l.Lock()
+		d.currBootstrap = newBootstrap
+		d.state = daemonStateRestarting
+		d.l.Unlock()
+
+		d.logger.Info(ctx, "Shutting down previous child processes")
+		if err := d.children.Shutdown(); err != nil {
+			d.logger.Fatal(ctx, "Failed to cleanly shutdown children, there may be orphaned child processes", err)
+		}
+	}
+}
+
+func (d *daemon) GetGarageBootstrapHosts(
+	ctx context.Context,
+) (
+	map[string]bootstrap.Host, error,
+) {
+	return withInnerChildren(d, func(*Children) (map[string]bootstrap.Host, error) {
+		return d.getGarageBootstrapHosts(ctx)
+	})
 }
 
 func (d *daemon) Shutdown() error {
-	d.pmuxCancelFn()
+	d.cancelFn()
-	<-d.pmuxStoppedCh
+	<-d.stoppedCh
 	return nil
 }

go/daemon/daemon_restarter.go

@@ -1,262 +0,0 @@
-package daemon
-
-import (
-	"bytes"
-	"context"
-	"errors"
-	"fmt"
-	"isle/bootstrap"
-	"sync"
-	"time"
-
-	"dev.mediocregopher.com/mediocre-go-lib.git/mlog"
-)
-
-const (
-	daemonRestarterStateInitializing = iota
-	daemonRestarterStateOk
-	daemonRestarterStateRestarting
-	daemonRestarterStateShutdown
-)
-
-type daemonRestarter struct {
-	logger        *mlog.Logger
-	daemonConfig  Config
-	envBinDirPath string
-	opts          *Opts
-
-	l             sync.Mutex
-	state         int
-	inner         Daemon
-	currBootstrap bootstrap.Bootstrap
-
-	cancelFn  context.CancelFunc
-	stoppedCh chan struct{}
-}
-
-// NewDaemonRestarter will wrap a Daemon such that it will be automatically
-// shutdown and re-created whenever there's changes in the cluster which require
-// the configuration to be changed (e.g. a new nebula lighthouse).
-//
-// While still starting up the daemon for the first time all methods will return
-// ErrInitializing, except Shutdown which will block until initialization is
-// canceled.
-//
-// During a restart all methods will return ErrRestarting, except Shutdown which
-// will block until the currently executing restart is finished and then
-// shutdown cleanly from there.
-//
-// TODO make daemonRestarter smarter, it currently restarts on _any_ change, but
-// it should restart itself only when there's something actually requiring a
-// restart.
-func NewDaemonRestarter(
-	logger *mlog.Logger,
-	daemonConfig Config,
-	envBinDirPath string,
-	currBootstrap bootstrap.Bootstrap,
-	opts *Opts,
-) Daemon {
-	ctx, cancelFn := context.WithCancel(context.Background())
-
-	dr := &daemonRestarter{
-		logger:        logger,
-		daemonConfig:  daemonConfig,
-		envBinDirPath: envBinDirPath,
-		opts:          opts.withDefaults(),
-		currBootstrap: currBootstrap,
-		cancelFn:      cancelFn,
-		stoppedCh:     make(chan struct{}),
-	}
-
-	go func() {
-		dr.restartLoop(ctx)
-		dr.logger.Debug(ctx, "DaemonRestarter stopped")
-		close(dr.stoppedCh)
-	}()
-
-	return dr
-}
-
-func withInnerDaemon[Res any](
-	dr *daemonRestarter, fn func(Daemon) (Res, error),
-) (Res, error) {
-	var zero Res
-	dr.l.Lock()
-	inner, state := dr.inner, dr.state
-	dr.l.Unlock()
-
-	switch state {
-	case daemonRestarterStateInitializing:
-		return zero, ErrInitializing
-	case daemonRestarterStateOk:
-		return fn(inner)
-	case daemonRestarterStateRestarting:
-		return zero, ErrRestarting
-	case daemonRestarterStateShutdown:
-		return zero, errors.New("already shutdown")
-	default:
-		panic(fmt.Sprintf("unknown state %d", dr.state))
-	}
-}
-
-// creates a new bootstrap file using available information from the network. If
-// the new bootstrap file is different than the existing one, the existing one
-// is overwritten and true is returned.
-func (dr *daemonRestarter) checkBootstrap(
-	ctx context.Context, hostBootstrap bootstrap.Bootstrap,
-) (
-	bootstrap.Bootstrap, bool, error,
-) {
-
-	thisHost := hostBootstrap.ThisHost()
-
-	newHosts, err := dr.inner.GetGarageBootstrapHosts(ctx)
-	if err != nil {
-		return bootstrap.Bootstrap{}, false, fmt.Errorf("getting hosts from garage: %w", err)
-	}
-
-	// the daemon's view of this host's bootstrap info takes precedence over
-	// whatever is in garage
-	newHosts[thisHost.Name] = thisHost
-
-	newHostsHash, err := bootstrap.HostsHash(newHosts)
-	if err != nil {
-		return bootstrap.Bootstrap{}, false, fmt.Errorf("calculating hash of new hosts: %w", err)
-	}
-
-	currHostsHash, err := bootstrap.HostsHash(hostBootstrap.Hosts)
-	if err != nil {
-		return bootstrap.Bootstrap{}, false, fmt.Errorf("calculating hash of current hosts: %w", err)
-	}
-
-	if bytes.Equal(newHostsHash, currHostsHash) {
-		return hostBootstrap, false, nil
-	}
-
-	hostBootstrap.Hosts = newHosts
-
-	return hostBootstrap, true, nil
-}
-
-// blocks until a new bootstrap is available or context is canceled
-func (dr *daemonRestarter) watchForChanges(ctx context.Context) bootstrap.Bootstrap {
-
-	ticker := time.NewTicker(3 * time.Minute)
-	defer ticker.Stop()
-
-	for {
-		select {
-
-		case <-ctx.Done():
-			return bootstrap.Bootstrap{}
-
-		case <-ticker.C:
-
-			dr.logger.Info(ctx, "Checking for changes to bootstrap")
-
-			newBootstrap, changed, err := dr.checkBootstrap(
-				ctx, dr.currBootstrap,
-			)
-			if err != nil {
-				dr.logger.Error(ctx, "Checking bootstrap for changes failed", err)
-				continue
-			} else if !changed {
-				continue
-			}
-
-			err = writeBootstrapToStateDir(dr.opts.EnvVars.StateDirPath, newBootstrap)
-			if err != nil {
-				dr.logger.Error(ctx, "Writing new bootstrap to disk failed", err)
-				continue
-			}
-
-			return newBootstrap
-		}
-	}
-}
-
-func (dr *daemonRestarter) restartLoop(ctx context.Context) {
-	defer func() {
-		dr.l.Lock()
-		dr.state = daemonRestarterStateShutdown
-		inner := dr.inner
-		dr.l.Unlock()
-
-		if inner != nil {
-			if err := inner.Shutdown(); err != nil {
-				dr.logger.Fatal(ctx, "failed to cleanly shutdown daemon, there may be orphaned child processes", err)
-			}
-		}
-	}()
-
-	wait := func(d time.Duration) bool {
-		select {
-		case <-ctx.Done():
-			return false
-		case <-time.After(d):
-			return true
-		}
-	}
-
-	for {
-		if ctx.Err() != nil {
-			return
-		}
-
-		dr.logger.Info(ctx, "Creating new daemon")
-		daemonInst, err := New(
-			ctx,
-			dr.logger.WithNamespace("daemon"),
-			dr.daemonConfig,
-			dr.currBootstrap,
-			dr.envBinDirPath,
-			dr.opts,
-		)
-		if errors.Is(err, context.Canceled) {
-			return
-		} else if err != nil {
-			dr.logger.Error(ctx, "failed to initialize daemon", err)
-			if !wait(1 * time.Second) {
-				return
-			}
-			continue
-		}
-
-		dr.l.Lock()
-		dr.inner = daemonInst
-		dr.state = daemonRestarterStateOk
-		dr.l.Unlock()
-
-		newBootstrap := dr.watchForChanges(ctx)
-		if ctx.Err() != nil {
-			return
-		}
-
-		dr.logger.Info(ctx, "Bootstrap has changed, will restart daemon")
-		dr.l.Lock()
-		dr.currBootstrap = newBootstrap
-		dr.state = daemonRestarterStateRestarting
-		dr.l.Unlock()
-
-		dr.logger.Info(ctx, "Shutting down previous daemon")
-		if err := dr.inner.Shutdown(); err != nil {
-			dr.logger.Fatal(ctx, "failed to cleanly shutdown daemon, there may be orphaned child processes", err)
-		}
-	}
-}
-
-func (dr *daemonRestarter) GetGarageBootstrapHosts(
-	ctx context.Context,
-) (
-	map[string]bootstrap.Host, error,
-) {
-	return withInnerDaemon(dr, func(inner Daemon) (map[string]bootstrap.Host, error) {
-		return inner.GetGarageBootstrapHosts(ctx)
-	})
-}
-
-func (dr *daemonRestarter) Shutdown() error {
-	dr.cancelFn()
-	<-dr.stoppedCh
-	return nil
-}

go/daemon/errors.go

@@ -3,11 +3,11 @@ package daemon
 import "isle/daemon/jsonrpc2"
 
 var (
-	// ErrInitializing is returned when a cluster is unavailable due to still
+	// ErrInitializing is returned when a network is unavailable due to still
 	// being initialized.
-	ErrInitializing = jsonrpc2.NewError(1, "Cluster is being initialized")
+	ErrInitializing = jsonrpc2.NewError(1, "Network is being initialized")
 
-	// ErrRestarting is returned when a cluster is unavailable due to being
+	// ErrRestarting is returned when a network is unavailable due to being
 	// restarted.
-	ErrRestarting = jsonrpc2.NewError(2, "Cluster is being restarted")
+	ErrRestarting = jsonrpc2.NewError(2, "Network is being restarted")
 )

go/daemon/global_bucket.go

@@ -24,7 +24,7 @@ const (
 // it.
 func (d *daemon) putGarageBoostrapHost(ctx context.Context) error {
 	var (
-		b      = d.hostBootstrap
+		b      = d.currBootstrap
 		host   = b.ThisHost()
 		client = b.GlobalBucketS3APIClient()
 	)
@@ -65,13 +65,13 @@ func (d *daemon) putGarageBoostrapHost(ctx context.Context) error {
 	return nil
 }
 
-func (d *daemon) GetGarageBootstrapHosts(
+func (d *daemon) getGarageBootstrapHosts(
 	ctx context.Context,
 ) (
 	map[string]bootstrap.Host, error,
 ) {
 	var (
-		b      = d.hostBootstrap
+		b      = d.currBootstrap
 		client = b.GlobalBucketS3APIClient()
 		hosts  = map[string]bootstrap.Host{}
 
@@ -106,13 +106,13 @@ func (d *daemon) GetGarageBootstrapHosts(
 		obj.Close()
 
 		if err != nil {
-			d.logger.Warn(ctx, "object contains invalid json", err)
+			d.logger.Warn(ctx, "Object contains invalid json", err)
 			continue
 		}
 
 		host, err := authedHost.Unwrap(b.CAPublicCredentials)
 		if err != nil {
-			d.logger.Warn(ctx, "host could not be authenticated", err)
+			d.logger.Warn(ctx, "Host could not be authenticated", err)
 		}
 
 		hosts[host.Name] = host

go/daemon/jigs.go

@@ -3,16 +3,28 @@ package daemon
 import (
 	"context"
 	"time"
+
+	"dev.mediocregopher.com/mediocre-go-lib.git/mlog"
 )
 
-func until(ctx context.Context, fn func(context.Context) error) error {
+// until keeps trying fn until it returns nil, returning true. If the context is
+// canceled then until returns false.
+func until(
+	ctx context.Context,
+	logger *mlog.Logger,
+	descr string,
+	fn func(context.Context) error,
+) bool {
 	for {
-		if err := fn(ctx); err == nil {
+		logger.Info(ctx, descr)
-			return nil
+		err := fn(ctx)
+		if err == nil {
+			return true
 		} else if ctxErr := ctx.Err(); ctxErr != nil {
-			return ctxErr
+			return false
 		}
 
+		logger.Warn(ctx, descr+" failed, retrying in one second", err)
 		time.Sleep(1 * time.Second)
 	}
 }

go/daemon/rpc.go

@@ -26,7 +26,7 @@ func NewRPC(daemon Daemon) *RPC {
 	return &RPC{daemon}
 }
 
-// GetHosts returns all hosts known to the cluster, sorted by their name.
+// GetHosts returns all hosts known to the network, sorted by their name.
 func (r *RPC) GetHosts(
 	ctx context.Context, req struct{},
 ) (

tests/cases/admin/01-create-network.sh

@@ -1,5 +1,5 @@
-# shellcheck source=../../utils/with-1-data-1-empty-node-cluster.sh
+# shellcheck source=../../utils/with-1-data-1-empty-node-network.sh
-source "$UTILS"/with-1-data-1-empty-node-cluster.sh
+source "$UTILS"/with-1-data-1-empty-node-network.sh
 
 [ "$(cat a/meta/isle/rpc_port)" = "3900" ]
 [ "$(cat b/meta/isle/rpc_port)" = "3910" ]

tests/cases/admin/02-create-bootstrap.sh

@@ -1,8 +1,8 @@
-# shellcheck source=../../utils/with-1-data-1-empty-node-cluster.sh
+# shellcheck source=../../utils/with-1-data-1-empty-node-network.sh
-source "$UTILS"/with-1-data-1-empty-node-cluster.sh
+source "$UTILS"/with-1-data-1-empty-node-network.sh
 
 adminBS="$XDG_STATE_HOME"/isle/bootstrap.json
-bs="$secondus_bootstrap" # set in with-1-data-1-empty-node-cluster.sh
+bs="$secondus_bootstrap" # set in with-1-data-1-empty-node-network.sh
 
 [ "$(jq -r <"$bs" '.AdminCreationParams')" = "$(jq -r <admin.json '.CreationParams')" ]
 [ "$(jq -r <"$bs" '.SignedHostAssigned.Body.Name')" = "secondus" ]

tests/cases/dnsmasq/00-hosts.sh

@@ -1,5 +1,5 @@
-# shellcheck source=../../utils/with-1-data-1-empty-node-cluster.sh
+# shellcheck source=../../utils/with-1-data-1-empty-node-network.sh
-source "$UTILS"/with-1-data-1-empty-node-cluster.sh
+source "$UTILS"/with-1-data-1-empty-node-network.sh
 
 function assert_a {
     want_ip="$1"

tests/cases/garage/00-cli.sh

@@ -1,5 +1,5 @@
-# shellcheck source=../../utils/with-1-data-1-empty-node-cluster.sh
+# shellcheck source=../../utils/with-1-data-1-empty-node-network.sh
-source "$UTILS"/with-1-data-1-empty-node-cluster.sh
+source "$UTILS"/with-1-data-1-empty-node-network.sh
 
 function do_tests {
     status="$(isle garage cli status | tail -n+3)"

tests/cases/garage/01-mc.sh

@@ -1,5 +1,5 @@
-# shellcheck source=../../utils/with-1-data-1-empty-node-cluster.sh
+# shellcheck source=../../utils/with-1-data-1-empty-node-network.sh
-source "$UTILS"/with-1-data-1-empty-node-cluster.sh
+source "$UTILS"/with-1-data-1-empty-node-network.sh
 
 function do_tests {
     files="$(isle garage mc -- tree --json garage)"

tests/cases/hosts/00-list.sh

@@ -1,5 +1,5 @@
-# shellcheck source=../../utils/with-1-data-1-empty-node-cluster.sh
+# shellcheck source=../../utils/with-1-data-1-empty-node-network.sh
-source "$UTILS"/with-1-data-1-empty-node-cluster.sh
+source "$UTILS"/with-1-data-1-empty-node-network.sh
 
 as_primus
 hosts="$(isle hosts list)"

tests/entrypoint.sh

@@ -92,8 +92,8 @@ for file in $test_files; do
 done
 
 
-# Clean up any shared running clusters. Each cleanup script is responsible for
+# Clean up any shared running networks. Each cleanup script is responsible for
-# figuring out if its shared cluster was actually instantiated during any tests.
+# figuring out if its shared network was actually instantiated during any tests.
 
 if [ -e "$ROOT_TMPDIR/cleanup-pids" ]; then
     echo "Cleaning up running pids"

tests/utils/with-1-data-1-empty-node-network.sh

@@ -25,7 +25,7 @@ as_primus
 secondus_bootstrap="$(pwd)/secondus-bootstrap.json"
 
 if [ ! -d "$XDG_RUNTIME_DIR/isle" ]; then
-    echo "Initializing shared single node cluster"
+    echo "Initializing shared single node network"
 
     mkdir a
     mkdir b
@@ -62,7 +62,7 @@ EOF
     pid="$!"
     echo "Waiting for primus daemon (process $pid) to initialize"
 
-    $SHELL "$UTILS/register-cleanup.sh" "$pid" "1-data-1-empty-node-cluster/primus"
+    $SHELL "$UTILS/register-cleanup.sh" "$pid" "1-data-1-empty-node-network/primus"
 
     while ! isle hosts list >/dev/null; do sleep 1; done
 
@@ -86,7 +86,7 @@ EOF
         pid="$!"
         echo "Waiting for secondus daemon (process $!) to initialize"
 
-        $SHELL "$UTILS/register-cleanup.sh" "$pid" "1-data-1-empty-node-cluster/secondus"
+        $SHELL "$UTILS/register-cleanup.sh" "$pid" "1-data-1-empty-node-network/secondus"
         while ! isle hosts list >/dev/null; do sleep 1; done
     )
 fi