Files
firecracker-orchestrator/orchestrator/snapshot.go
Honza Novak 04067f7e6b feat: add structured logging, --dev flag, and snapshot network_overrides
- Add --dev flag to main that enables logrus caller info (file:line) for
  easier debugging without changing production log output
- Wire firecracker SDK logger (WithLogger) and FIFO log file to both the
  golden VM and each clone machine so Firecracker's own logs are surfaced
- Log the exact shell commands being run (cp --reflink, ip tuntap, ip link,
  firecracker binary) at Info level before each syscall/exec, making it
  straightforward to reproduce steps manually
- Extract snapshot.go with loadSnapshotWithNetworkOverride: a direct PUT
  /snapshot/load call over the Unix socket that includes network_overrides,
  remapping the stored tap to the per-clone tap name (Firecracker v1.15+
  feature not yet exposed by SDK v1.0.0)
- Use firecracker.WithSnapshot + a Handlers.FcInit.Swap to replace the SDK's
  LoadSnapshotHandler with the above when Bridge != "none"

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-13 09:07:35 +00:00

72 lines
2.0 KiB
Go

package orchestrator
import (
"bytes"
"context"
"encoding/json"
"fmt"
"io"
"net"
"net/http"
)
type networkOverride struct {
IfaceID string `json:"iface_id"`
HostDevName string `json:"host_dev_name"`
}
type snapshotLoadRequest struct {
MemFilePath string `json:"mem_file_path"`
SnapshotPath string `json:"snapshot_path"`
ResumeVM bool `json:"resume_vm,omitempty"`
NetworkOverrides []networkOverride `json:"network_overrides,omitempty"`
}
// loadSnapshotWithNetworkOverride calls PUT /snapshot/load on the Firecracker
// Unix socket, remapping the first network interface to tapName.
// This bypasses the SDK's LoadSnapshotHandler which doesn't expose
// network_overrides (added in Firecracker v1.15, SDK v1.0.0 omits it).
func loadSnapshotWithNetworkOverride(ctx context.Context, sockPath, memPath, vmstatePath, tapName string) error {
payload := snapshotLoadRequest{
MemFilePath: memPath,
SnapshotPath: vmstatePath,
ResumeVM: true,
NetworkOverrides: []networkOverride{
{IfaceID: "1", HostDevName: tapName},
},
}
data, err := json.Marshal(payload)
if err != nil {
return fmt.Errorf("marshal snapshot load params: %w", err)
}
httpClient := &http.Client{
Transport: &http.Transport{
DialContext: func(ctx context.Context, _, _ string) (net.Conn, error) {
return net.Dial("unix", sockPath)
},
},
}
req, err := http.NewRequestWithContext(ctx, http.MethodPut,
"http://localhost/snapshot/load", bytes.NewReader(data))
if err != nil {
return fmt.Errorf("build snapshot load request: %w", err)
}
req.Header.Set("Content-Type", "application/json")
req.Header.Set("Accept", "application/json")
resp, err := httpClient.Do(req)
if err != nil {
return fmt.Errorf("snapshot load request: %w", err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusNoContent {
body, _ := io.ReadAll(resp.Body)
return fmt.Errorf("snapshot load failed (%d): %s", resp.StatusCode, body)
}
return nil
}