relax relationship between corrosion service, init cluster with new store

internal/machine/cluster/cluster.go

@@ -3,6 +3,7 @@ package cluster
 import (
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
@@ -10,6 +11,7 @@ import (
 	"google.golang.org/protobuf/types/known/emptypb"
 	"log/slog"
 	"net/netip"
+	"time"
 	"uncloud/internal/machine/api/pb"
 	"uncloud/internal/machine/network"
 	"uncloud/internal/machine/store"
@@ -34,6 +36,35 @@ func NewCluster(state *State, store *store.Store) *Cluster {
 	}
 }
 
+func (c *Cluster) Init(ctx context.Context, network netip.Prefix) error {
+	initialised, err := c.Initialised(ctx)
+	if err != nil {
+		return err
+	}
+	if initialised {
+		return fmt.Errorf("cluster already initialized")
+	}
+
+	if err = c.store.Put(ctx, "network", network.String()); err != nil {
+		return fmt.Errorf("put network to store: %w", err)
+	}
+	if err = c.store.Put(ctx, "created_at", time.Now().UTC().Format(time.RFC3339)); err != nil {
+		return fmt.Errorf("put created_at to store: %w", err)
+	}
+	return nil
+}
+
+func (c *Cluster) Initialised(ctx context.Context) (bool, error) {
+	var createdAt string
+	if err := c.store.Get(ctx, "created_at", &createdAt); err != nil {
+		if errors.Is(err, store.ErrKeyNotFound) {
+			return false, nil
+		}
+		return false, fmt.Errorf("get created_at from store: %w", err)
+	}
+	return true, nil
+}
+
 func (c *Cluster) SetState(state *State) {
 	c.state = state
 }

internal/machine/machine.go

@@ -144,7 +144,7 @@ func NewMachine(config *Config) (*Machine, error) {
 	}
 	m.localServer = newGRPCServer(m, c)
 
-	if m.IsInitialised() {
+	if m.Initialised() {
 		m.initialised <- struct{}{}
 	}
 
@@ -163,9 +163,9 @@ func (m *Machine) Started() <-chan struct{} {
 	return m.started
 }
 
-// IsInitialised returns true if the machine has been configured as a member of a cluster,
+// Initialised 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 {
+func (m *Machine) Initialised() bool {
 	m.state.mu.RLock()
 	defer m.state.mu.RUnlock()
 
@@ -173,6 +173,19 @@ func (m *Machine) IsInitialised() bool {
 }
 
 func (m *Machine) Run(ctx context.Context) error {
+	// Configure and start the corrosion service on the loopback if the machine is not initialised as a cluster
+	// member. This provides the store required for the machine to initialise a new cluster on it.
+	if !m.Initialised() {
+		if err := m.configureCorrosion(); err != nil {
+			return fmt.Errorf("configure corrosion service: %w", err)
+		}
+		slog.Info("Configured corrosion service.", "dir", m.config.CorrosionDir)
+
+		if err := m.config.CorrosionService.Start(); err != nil {
+			return fmt.Errorf("start corrosion service: %w", err)
+		}
+	}
+
 	// Use an errgroup to coordinate error handling and graceful shutdown of multiple machine components.
 	errGroup, ctx := errgroup.WithContext(ctx)
 
@@ -192,28 +205,10 @@ func (m *Machine) Run(ctx context.Context) error {
 	)
 	close(m.started)
 
-	// Configure and start the corrosion service on the loopback if the machine is not initialised as a cluster
-	// member. This provides the store required for the machine to initialise a new cluster on it.
-	if !m.IsInitialised() {
-		// Needs to run in a goroutine because the corrosion systemd service depends on the readiness of the daemon
-		// indicated by closing the started channel.
-		errGroup.Go(func() error {
-			if err := m.configureCorrosion(); err != nil {
-				return fmt.Errorf("configure corrosion service: %w", err)
-			}
-			slog.Info("Configured corrosion service.", "dir", m.config.CorrosionDir)
-
-			if err := m.config.CorrosionService.Start(); err != nil {
-				return fmt.Errorf("start corrosion service: %w", err)
-			}
-			return nil
-		})
-	}
-
 	// Control loop for managing the network controller.
 	errGroup.Go(
 		func() error {
-			if !m.IsInitialised() {
+			if !m.Initialised() {
 				slog.Info(
 					"Waiting for the machine to be initialised as a member of a cluster " +
 						"to start the network controller.",
@@ -386,6 +381,15 @@ func (m *Machine) InitCluster(ctx context.Context, req *pb.InitClusterRequest) (
 		return nil, status.Errorf(codes.InvalidArgument, "set cluster network: %v", err)
 	}
 
+	clusterNetwork, err := req.Network.ToPrefix()
+	if err != nil {
+		return nil, status.Errorf(codes.InvalidArgument, "invalid network: %v", err)
+	}
+	if err = m.cluster.Init(ctx, clusterNetwork); err != nil {
+		return nil, status.Errorf(codes.Internal, "init cluster: %v", err)
+	}
+	slog.Info("Cluster initialised.", "network", clusterNetwork.String())
+
 	// Use the public and all routable IPs as endpoints.
 	ips, err := network.ListRoutableIPs()
 	if err != nil {

internal/machine/store/schema.sql

@@ -1,3 +1,10 @@
+-- cluster table stores the key-value pairs of the cluster configuration.
+CREATE TABLE cluster
+(
+    key   TEXT NOT NULL PRIMARY KEY,
+    value ANY
+);
+
 CREATE TABLE machines
 (
     id   TEXT NOT NULL PRIMARY KEY,

internal/machine/store/store.go

@@ -1,14 +1,20 @@
 package store
 
 import (
+	"context"
 	_ "embed"
+	"errors"
 	"fmt"
 	"uncloud/internal/corrosion"
 	"uncloud/internal/machine/api/pb"
 )
 
+var (
 	//go:embed schema.sql
-var Schema string
+	Schema string
+
+	ErrKeyNotFound = errors.New("key not found")
+)
 
 // Store is a cluster store backed by a distributed Corrosion database.
 type Store struct {
@@ -19,6 +25,28 @@ func New(corro *corrosion.APIClient) *Store {
 	return &Store{corro: corro}
 }
 
+func (s *Store) Get(ctx context.Context, key string, value any) error {
+	rows, err := s.corro.QueryContext(ctx, "SELECT value FROM cluster WHERE key = ?", key)
+	if err != nil {
+		return err
+	}
+	if !rows.Next() {
+		if rows.Err() != nil {
+			return rows.Err()
+		}
+		return ErrKeyNotFound
+	}
+	if err = rows.Scan(value); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (s *Store) Put(ctx context.Context, key string, value any) error {
+	_, err := s.corro.ExecContext(ctx, "INSERT OR REPLACE INTO cluster (key, value) VALUES (?, ?)", key, value)
+	return err
+}
+
 func (s *Store) CreateMachine(machine *pb.MachineInfo) error {
 	return fmt.Errorf("not implemented")
 }

scripts/install.sh

@@ -177,8 +177,7 @@ install_corrosion_systemd() {
     cat > "${corrosion_service_path}" << EOF
 [Unit]
 Description=Uncloud gossip-based distributed store
-After=uncloud.service
+PartOf=uncloud.service
-Requires=uncloud.service
 
 [Service]
 Type=simple