convert systemd unit to Type=notify and report readiness

go.mod

@@ -7,7 +7,7 @@ toolchain go1.22.5
 require (
 	github.com/BurntSushi/toml v1.4.0
 	github.com/dgraph-io/badger/v3 v3.2103.5
-	github.com/docker/docker v27.2.1+incompatible
+	github.com/docker/docker v27.3.0+incompatible
 	github.com/docker/go-connections v0.5.0
 	github.com/hashicorp/memberlist v0.5.1
 	github.com/hashicorp/serf v0.10.1
@@ -47,6 +47,7 @@ require (
 	github.com/cespare/xxhash v1.1.0 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/containerd/log v0.1.0 // indirect
+	github.com/coreos/go-systemd v0.0.0-20191104093116-d3cd4ed1dbcf // indirect
 	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.3.0 // indirect
 	github.com/dgraph-io/ristretto v0.1.1 // indirect
 	github.com/distribution/reference v0.6.0 // indirect

go.sum

@@ -63,6 +63,8 @@ github.com/containerd/log v0.1.0/go.mod h1:VRRf09a7mHDIRezVKTRCrOq78v577GXq3bSa3
 github.com/coreos/etcd v3.3.10+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
 github.com/coreos/go-etcd v2.0.0+incompatible/go.mod h1:Jez6KQU2B/sWsbdaef3ED8NzMklzPG4d5KIOhIy30Tk=
 github.com/coreos/go-semver v0.2.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
+github.com/coreos/go-systemd v0.0.0-20191104093116-d3cd4ed1dbcf h1:iW4rZ826su+pqaw19uhpSCzhj44qo35pNgKFGqzDKkU=
+github.com/coreos/go-systemd v0.0.0-20191104093116-d3cd4ed1dbcf/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
 github.com/coreos/go-systemd/v22 v22.5.0 h1:RrqgGjYQKalulkV8NGVIfkXQf6YYmOyiJKk8iXXhfZs=
 github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
 github.com/cpuguy83/go-md2man v1.0.10/go.mod h1:SmD6nW6nTyfqj6ABTjUi3V3JVMnlJmwcJI5acqYI6dE=
@@ -89,8 +91,8 @@ github.com/dgryski/go-farm v0.0.0-20190423205320-6a90982ecee2 h1:tdlZCpZ/P9DhczC
 github.com/dgryski/go-farm v0.0.0-20190423205320-6a90982ecee2/go.mod h1:SqUrOPUnsFjfmXRMNPybcSiG0BgUW2AuFH8PAnS2iTw=
 github.com/distribution/reference v0.6.0 h1:0IXCQ5g4/QMHHkarYzh5l+u8T3t73zM5QvfrDyIgxBk=
 github.com/distribution/reference v0.6.0/go.mod h1:BbU0aIcezP1/5jX/8MP0YiH4SdvB5Y4f/wlDRiLyi3E=
-github.com/docker/docker v27.2.1+incompatible h1:fQdiLfW7VLscyoeYEBz7/J8soYFDZV1u6VW6gJEjNMI=
+github.com/docker/docker v27.3.0+incompatible h1:BNb1QY6o4JdKpqwi9IB+HUYcRRrVN4aGFUTvDmWYK1A=
-github.com/docker/docker v27.2.1+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
+github.com/docker/docker v27.3.0+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
 github.com/docker/go-connections v0.5.0 h1:USnMq7hx7gwdVZq1L49hLXaFtUdTADjXGp+uj1Br63c=
 github.com/docker/go-connections v0.5.0/go.mod h1:ov60Kzw0kKElRwhNs9UlUHAE/F9Fe6GLaXnqyDdmEXc=
 github.com/docker/go-events v0.0.0-20190806004212-e31b211e4f1c h1:+pKlWGMw7gf6bQ+oDZB4KHQFypsfjYlq/C4rfL7D3g8=

internal/daemon/daemon.go

@@ -3,6 +3,7 @@ package daemon
 import (
 	"context"
 	"fmt"
+	systemd "github.com/coreos/go-systemd/daemon"
 	"log/slog"
 	"uncloud/internal/machine"
 )
@@ -27,5 +28,18 @@ func New(dataDir string) (*Daemon, error) {
 
 func (d *Daemon) Run(ctx context.Context) error {
 	slog.Info("Starting machine.")
+
+	// Notify systemd that the daemon is ready when the machine is started.
+	go func() {
+		select {
+		case <-d.machine.Started():
+			_, err := systemd.SdNotify(false, systemd.SdNotifyReady)
+			if err != nil {
+				slog.Error("Failed to notify systemd that the daemon is ready.", "error", err)
+			}
+		case <-ctx.Done():
+		}
+	}()
+
 	return d.machine.Run(ctx)
 }

internal/machine/machine.go

@@ -37,6 +37,8 @@ type Machine struct {
 
 	config Config
 	state  *State
+	// started is closed when the machine is ready to serve requests on the local API server.
+	started chan struct{}
 	// initialised is signalled when the machine is configured as a member of a cluster.
 	initialised chan struct{}
 
@@ -90,6 +92,7 @@ func NewMachine(config *Config) (*Machine, error) {
 	m := &Machine{
 		config:        *config,
 		state:         state,
+		started:       make(chan struct{}),
 		initialised:   make(chan struct{}, 1),
 		cluster:       c,
 		newMachinesCh: c.WatchNewMachines(),
@@ -110,6 +113,11 @@ func newGRPCServer(m pb.MachineServer, c pb.ClusterServer) *grpc.Server {
 	return s
 }
 
+// Started returns a channel that is closed when the machine is ready to serve requests on the local API server.
+func (m *Machine) Started() <-chan struct{} {
+	return m.started
+}
+
 // IsInitialised returns true if the machine has been configured as a member of a cluster,
 // either by initialising a new cluster on it or joining an existing one.
 func (m *Machine) IsInitialised() bool {
@@ -141,6 +149,7 @@ func (m *Machine) Run(ctx context.Context) error {
 			return nil
 		},
 	)
+	close(m.started)
 
 	// Control loop for managing the network controller.
 	errGroup.Go(

scripts/install.sh

@@ -7,7 +7,7 @@ INSTALL_SYSTEMD_DIR=${INSTALL_SYSTEMD_DIR:-/etc/systemd/system}
 UNCLOUD_GITHUB_URL="https://github.com/psviderski/uncloud"
 UNCLOUD_VERSION=${UNCLOUD_VERSION:-latest}
 UNCLOUD_GROUP="uncloud"
-# Add the specified Linux user to group $UNCLOUD_GROUP.
+# Add the specified Linux user to group $UNCLOUD_GROUP to allow the user to run uncloud commands without sudo.
 UNCLOUD_GROUP_ADD_USER=${UNCLOUD_GROUP_ADD_USER:-}
 
 log() {
@@ -137,8 +137,9 @@ After=network-online.target
 Wants=network-online.target
 
 [Service]
-Type=simple
+Type=notify
 ExecStart=${INSTALL_BIN_DIR}/uncloudd
+TimeoutStartSec=15
 Restart=always
 RestartSec=2
 
@@ -160,7 +161,9 @@ EOF
     # Reload systemd to recognize the new or updated unit file.
     systemctl daemon-reload
     systemctl enable uncloud.service
-    systemctl start uncloud.service
+
+    log "⏳ Starting Uncloud machine daemon (uncloud.service)..."
+    systemctl restart uncloud.service
     log "✓ Uncloud machine daemon started."
 }