feat: enhance EvoBGP with new command-line options for the evobgp-agent, including a watch command for periodic configuration updates. Update go.mod with additional dependencies and improve Docker Compose setup for new services, including NATS and various worker components.

internal/birddeploy/apply.go

@@ -0,0 +1,141 @@
+// Package birddeploy applies revision preview fragments to a shared BIRD volume with parse-check and LKG (plan §13).
+package birddeploy
+
+import (
+	"context"
+	"fmt"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"evobgp/internal/birdfmt"
+	"evobgp/internal/store"
+)
+
+// Config drives two-phase deploy from a revision in the store.
+type Config struct {
+	ActiveDir  string // e.g. /etc/bird (live config tree)
+	StagingDir string // e.g. /tmp/evobgp-staging (same host/volume as ActiveDir)
+	BirdBin    string
+	BirdcBin   string
+	Socket     string // birdc -s
+}
+
+// ApplyRevision writes preview fragments to staging, runs bird -p, swaps into active, runs birdc configure; restores LKG on failure.
+func ApplyRevision(ctx context.Context, ctl *birdfmt.BirdCtl, rev *store.Revision, cfg Config) error {
+	if rev == nil || len(rev.PreviewFragments) == 0 {
+		return fmt.Errorf("birddeploy: no preview fragments")
+	}
+	active := strings.TrimSpace(cfg.ActiveDir)
+	staging := strings.TrimSpace(cfg.StagingDir)
+	if active == "" || staging == "" {
+		return fmt.Errorf("birddeploy: ActiveDir and StagingDir required")
+	}
+	if err := os.MkdirAll(staging, 0o755); err != nil {
+		return err
+	}
+	if err := os.MkdirAll(filepath.Join(active, "bird.d"), 0o755); err != nil {
+		return err
+	}
+	lkg := filepath.Join(active, ".evobgp_lkg")
+
+	// Phase 1: write staging tree
+	for rel, content := range rev.PreviewFragments {
+		rel = strings.TrimPrefix(rel, "/")
+		dst := filepath.Join(staging, rel)
+		if err := os.MkdirAll(filepath.Dir(dst), 0o755); err != nil {
+			return err
+		}
+		if err := os.WriteFile(dst, []byte(content), 0o644); err != nil {
+			return err
+		}
+	}
+	mainConf := filepath.Join(staging, "bird.conf")
+	if _, err := os.Stat(mainConf); err != nil {
+		return fmt.Errorf("birddeploy: staging missing bird.conf: %w", err)
+	}
+	bc := ctl
+	if bc == nil {
+		bc = &birdfmt.BirdCtl{Bird: cfg.BirdBin, Birdc: cfg.BirdcBin, Socket: cfg.Socket}
+	}
+	if err := bc.ParseCheck(ctx, mainConf); err != nil {
+		return fmt.Errorf("birddeploy: bird -p failed: %w", err)
+	}
+
+	// Snapshot LKG (best-effort copy of current active bird.conf + bird.d)
+	_ = os.RemoveAll(lkg)
+	_ = snapshotBirdTree(active, lkg)
+
+	// Phase 2: atomic swap into active
+	for rel, content := range rev.PreviewFragments {
+		rel = strings.TrimPrefix(rel, "/")
+		dst := filepath.Join(active, rel)
+		if err := os.MkdirAll(filepath.Dir(dst), 0o755); err != nil {
+			_ = restoreLKG(lkg, active)
+			return err
+		}
+		tmp := dst + ".tmp"
+		if err := os.WriteFile(tmp, []byte(content), 0o644); err != nil {
+			_ = restoreLKG(lkg, active)
+			return err
+		}
+		if err := os.Rename(tmp, dst); err != nil {
+			_ = restoreLKG(lkg, active)
+			return err
+		}
+	}
+	if err := bc.Configure(ctx); err != nil {
+		_ = restoreLKG(lkg, active)
+		_ = bc.Configure(ctx)
+		return fmt.Errorf("birddeploy: birdc configure failed, restored LKG: %w", err)
+	}
+	return nil
+}
+
+func snapshotBirdTree(activeRoot, dstRoot string) error {
+	if err := os.MkdirAll(dstRoot, 0o755); err != nil {
+		return err
+	}
+	mc := filepath.Join(activeRoot, "bird.conf")
+	if b, err := os.ReadFile(mc); err == nil {
+		_ = os.WriteFile(filepath.Join(dstRoot, "bird.conf"), b, 0o644)
+	}
+	bd := filepath.Join(activeRoot, "bird.d")
+	if st, err := os.Stat(bd); err == nil && st.IsDir() {
+		_ = filepath.WalkDir(bd, func(path string, d fs.DirEntry, err error) error {
+			if err != nil || d.IsDir() {
+				return err
+			}
+			suffix, _ := filepath.Rel(activeRoot, path)
+			out := filepath.Join(dstRoot, suffix)
+			_ = os.MkdirAll(filepath.Dir(out), 0o755)
+			b, err := os.ReadFile(path)
+			if err != nil {
+				return nil
+			}
+			return os.WriteFile(out, b, 0o644)
+		})
+	}
+	return nil
+}
+
+func restoreLKG(lkg, active string) error {
+	if _, err := os.Stat(filepath.Join(lkg, "bird.conf")); err != nil {
+		return err
+	}
+	_ = filepath.WalkDir(lkg, func(path string, d fs.DirEntry, err error) error {
+		if err != nil || d.IsDir() {
+			return err
+		}
+		suffix, _ := filepath.Rel(lkg, path)
+		out := filepath.Join(active, suffix)
+		_ = os.MkdirAll(filepath.Dir(out), 0o755)
+		b, err := os.ReadFile(path)
+		if err != nil {
+			return nil
+		}
+		return os.WriteFile(out, b, 0o644)
+	})
+	return nil
+}