WAL-Archiving + PITR

cmd/monitor/main.go

@@ -4,9 +4,11 @@ import (
 	"context"
 	"fmt"
 	"log"
+	"os"
 	"time"
 
 	"github.com/fly-apps/postgres-flex/internal/flypg"
+	"github.com/fly-apps/postgres-flex/internal/flypg/state"
 )
 
 var (
@@ -16,8 +18,13 @@ var (
 
 	defaultDeadMemberRemovalThreshold   = time.Hour * 12
 	defaultInactiveSlotRemovalThreshold = time.Hour * 12
+
+	defaultBackupRetentionEvalFrequency = time.Hour * 12
+	defaultFullBackupSchedule           = time.Hour * 24
 )
 
+// TODO - Harden this so one failure doesn't take down the whole monitor
+
 func main() {
 	ctx := context.Background()
 
@@ -28,19 +35,69 @@ func main() {
 		panic(fmt.Sprintf("failed to reference node: %s\n", err))
 	}
 
+	// Wait for postgres to boot and become accessible.
+	log.Println("Waiting for Postgres to be ready...")
+	waitOnPostgres(ctx, node)
+	log.Println("Postgres is ready to accept connections. Starting monitor...")
+
 	// Dead member monitor
-	log.Println("Monitoring dead members")
 	go func() {
 		if err := monitorDeadMembers(ctx, node); err != nil {
 			panic(err)
 		}
 	}()
 
+	if os.Getenv("S3_ARCHIVE_CONFIG") != "" {
+		store, err := state.NewStore()
+		if err != nil {
+			panic(fmt.Errorf("failed initialize cluster state store: %s", err))
+		}
+
+		barman, err := flypg.NewBarman(store, os.Getenv("S3_ARCHIVE_CONFIG"), flypg.DefaultAuthProfile)
+		if err != nil {
+			panic(err)
+		}
+
+		if err := barman.LoadConfig(flypg.DefaultBarmanConfigDir); err != nil {
+			panic(err)
+		}
+
+		// Backup scheduler
+		go monitorBackupSchedule(ctx, barman)
+
+		// Backup retention monitor
+		go monitorBackupRetention(ctx, barman)
+	}
+
 	// Readonly monitor
-	log.Println("Monitoring cluster state")
 	go monitorClusterState(ctx, node)
 
 	// Replication slot monitor
-	log.Println("Monitoring replication slots")
 	monitorReplicationSlots(ctx, node)
 }
+
+func waitOnPostgres(ctx context.Context, node *flypg.Node) {
+	ticker := time.NewTicker(5 * time.Second)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			conn, err := node.NewLocalConnection(ctx, "postgres", node.SUCredentials)
+			if err != nil {
+				log.Printf("failed to open local connection: %s", err)
+				continue
+			}
+			defer func() { _ = conn.Close(ctx) }()
+
+			if err := conn.Ping(ctx); err != nil {
+				log.Printf("failed to ping local connection: %s", err)
+				continue
+			}
+
+			return
+		}
+	}
+}

cmd/monitor/monitor_backup_retention.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"context"
+	"log"
+	"time"
+
+	"github.com/fly-apps/postgres-flex/internal/flypg"
+)
+
+func monitorBackupRetention(ctx context.Context, barman *flypg.Barman) {
+	ticker := time.NewTicker(defaultBackupRetentionEvalFrequency)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			log.Println("Shutting down backup retention monitor")
+			return
+		case <-ticker.C:
+			result, err := barman.WALArchiveDelete(ctx)
+			if err != nil {
+				log.Printf("Backup retention failed with: %s", err)
+			}
+
+			if len(result) > 0 {
+				log.Printf("Backup retention response: %s", result)
+			}
+		}
+	}
+}

cmd/monitor/monitor_backup_schedule.go

@@ -0,0 +1,123 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/fly-apps/postgres-flex/internal/flypg"
+)
+
+func monitorBackupSchedule(ctx context.Context, barman *flypg.Barman) {
+	// Determine when the last backup was taken.
+	lastBackupTime, err := barman.LastCompletedBackup(ctx)
+	if err != nil {
+		log.Printf("Failed to resolve the last backup taken: %s", err)
+	}
+
+	fullBackupSchedule := defaultFullBackupSchedule
+
+	// Set the full backup schedule if it is defined in the configuration.
+	if barman.Settings.FullBackupFrequency != "" {
+		fullBackupDur, err := time.ParseDuration(barman.Settings.FullBackupFrequency)
+		switch {
+		case err != nil:
+			log.Printf("Failed to parse full backup frequency: %s", err)
+		default:
+			fullBackupSchedule = fullBackupDur
+		}
+	}
+
+	// Ensure we have a least one backup before proceeding.
+	if lastBackupTime.IsZero() {
+		log.Println("No backups found! Performing the initial base backup.")
+
+		if err := performInitialBaseBackup(ctx, barman); err != nil {
+			log.Printf("Failed to perform the initial full backup: %s", err)
+			log.Printf("Backup scheduler will re-attempt in %s.", fullBackupSchedule)
+		}
+
+		lastBackupTime = time.Now()
+	}
+
+	log.Printf("Full backup schedule set to: %s", fullBackupSchedule)
+
+	// Calculate the time until the next backup is due.
+	timeUntilNextBackup := time.Until(lastBackupTime.Add(fullBackupSchedule))
+
+	// Perform backup immediately if the time until the next backup is negative.
+	if timeUntilNextBackup < 0 {
+		log.Println("Performing full backup now")
+		_, err := barman.Backup(ctx, false)
+		if err != nil {
+			log.Printf("Full backup failed with: %s", err)
+		}
+
+		timeUntilNextBackup = fullBackupSchedule
+	}
+
+	log.Printf("Next full backup due in: %s", timeUntilNextBackup)
+
+	ticker := time.NewTicker(timeUntilNextBackup)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			log.Println("Shutting down backup scheduler")
+			return
+		case <-ticker.C:
+			// Perform a backup while passively waiting for the checkpoint process to complete.
+			// This could actually take a while, so we should be prepared to wait.
+			log.Println("Performing full backup")
+			_, err := barman.Backup(ctx, false)
+			if err != nil {
+				// TODO - Implement a backup-off strategy.
+				timeUntilNextBackup = time.Hour * 1
+				ticker.Reset(timeUntilNextBackup)
+
+				log.Printf("Backup retention failed with: %s.", err)
+				log.Printf("Backup will be re-attempted in %s.", timeUntilNextBackup)
+
+				continue
+			}
+
+			log.Printf("Full backup completed successfully")
+			ticker.Reset(fullBackupSchedule)
+		}
+	}
+}
+
+func performInitialBaseBackup(ctx context.Context, barman *flypg.Barman) error {
+	maxRetries := 10
+	retryCount := 0
+	for {
+		select {
+		case <-ctx.Done():
+			return nil
+		default:
+			_, err := barman.Backup(ctx, true)
+			if err != nil {
+				log.Printf("Failed to perform the initial full backup: %s. Retrying in 30 seconds.", err)
+
+				// If we've exceeded the maximum number of retries, we should return an error.
+				if retryCount >= maxRetries {
+					return fmt.Errorf("failed to perform the initial full backup after %d retries", maxRetries)
+				}
+
+				retryCount++
+
+				select {
+				case <-ctx.Done():
+					return ctx.Err()
+				case <-time.After(time.Second * 30):
+					continue
+				}
+			}
+
+			log.Println("Initial full backup completed successfully")
+			return nil
+		}
+	}
+}

cmd/monitor/monitor_dead_members.go

@@ -37,8 +37,6 @@ func monitorDeadMembers(ctx context.Context, node *flypg.Node) error {
 	ticker := time.NewTicker(deadMemberMonitorFrequency)
 	defer ticker.Stop()
 
-	log.Printf("Pruning every %s...\n", removalThreshold)
-
 	for range ticker.C {
 		err := deadMemberMonitorTick(ctx, node, seenAt, removalThreshold)
 		if err != nil {

cmd/start/main.go

@@ -23,6 +23,7 @@ func main() {
 		}
 	}
 
+	// Deprecated - We are moving away from having a separate barman Machine
 	if os.Getenv("IS_BARMAN") != "" {
 		node, err := flybarman.NewNode()
 		if err != nil {
@@ -54,6 +55,14 @@ func main() {
 		return
 	}
 
+	// TODO - Find a better way to handle this
+	if os.Getenv("S3_ARCHIVE_CONFIG") != "" || os.Getenv("S3_ARCHIVE_REMOTE_RESTORE_CONFIG") != "" {
+		if err := os.Setenv("AWS_SHARED_CREDENTIALS_FILE", "/data/.aws/credentials"); err != nil {
+			panicHandler(err)
+			return
+		}
+	}
+
 	node, err := flypg.NewNode()
 	if err != nil {
 		panicHandler(err)

internal/api/handle_admin.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"os"
 	"strings"
 
 	"github.com/fly-apps/postgres-flex/internal/flypg"
@@ -298,3 +299,100 @@ func handleViewRepmgrSettings(w http.ResponseWriter, r *http.Request) {
 	resp := &Response{Result: out}
 	renderJSON(w, resp, http.StatusOK)
 }
+
+func handleViewBarmanSettings(w http.ResponseWriter, _ *http.Request) {
+	if os.Getenv("S3_ARCHIVE_CONFIG") == "" {
+		renderErr(w, fmt.Errorf("barman is not enabled"))
+		return
+	}
+
+	store, err := state.NewStore()
+	if err != nil {
+		renderErr(w, err)
+		return
+	}
+
+	barman, err := flypg.NewBarman(store, os.Getenv("S3_ARCHIVE_CONFIG"), flypg.DefaultAuthProfile)
+	if err != nil {
+		renderErr(w, err)
+		return
+	}
+
+	if err := barman.LoadConfig(flypg.DefaultBarmanConfigDir); err != nil {
+		renderErr(w, err)
+		return
+	}
+
+	all, err := barman.CurrentConfig()
+	if err != nil {
+		renderErr(w, err)
+		return
+	}
+
+	resp := &Response{Result: all}
+	renderJSON(w, resp, http.StatusOK)
+}
+
+func handleUpdateBarmanSettings(w http.ResponseWriter, r *http.Request) {
+	if os.Getenv("S3_ARCHIVE_CONFIG") == "" {
+		renderErr(w, fmt.Errorf("barman is not enabled"))
+		return
+	}
+
+	store, err := state.NewStore()
+	if err != nil {
+		renderErr(w, err)
+		return
+	}
+
+	barman, err := flypg.NewBarman(store, os.Getenv("S3_ARCHIVE_CONFIG"), flypg.DefaultAuthProfile)
+	if err != nil {
+		renderErr(w, err)
+		return
+	}
+
+	if err := barman.LoadConfig(flypg.DefaultBarmanConfigDir); err != nil {
+		renderErr(w, err)
+		return
+	}
+
+	cfg, err := flypg.ReadFromFile(barman.UserConfigFile())
+	if err != nil {
+		renderErr(w, err)
+		return
+	}
+
+	var requestedChanges map[string]interface{}
+	if err := json.NewDecoder(r.Body).Decode(&requestedChanges); err != nil {
+		renderErr(w, err)
+		return
+	}
+
+	if err := barman.Validate(requestedChanges); err != nil {
+		renderErr(w, err)
+		return
+	}
+
+	for k, v := range requestedChanges {
+		cfg[k] = v
+	}
+
+	barman.SetUserConfig(cfg)
+
+	if err := flypg.PushUserConfig(barman, store); err != nil {
+		renderErr(w, err)
+		return
+	}
+
+	if err := flypg.SyncUserConfig(barman, store); err != nil {
+		renderErr(w, err)
+		return
+	}
+
+	res := &Response{Result: SettingsUpdate{
+		Message:         "Updated",
+		RestartRequired: true,
+	}}
+
+	renderJSON(w, res, http.StatusOK)
+}