banger/internal/model/types.go
Thales Maciel 687fcf0b59
vm state: split transient kernel/process handles off the durable schema
Separates what a VM IS (durable intent + identity + deterministic
derived paths — `VMRuntime`) from what is CURRENTLY TRUE about it
(firecracker PID, tap device, loop devices, dm-snapshot target — new
`VMHandles`). The durable state lives in the SQLite `vms` row; the
transient state lives in an in-memory cache on the daemon plus a
per-VM `handles.json` scratch file inside VMDir, rebuilt at startup
from OS inspection. Nothing kernel-level rides the SQLite schema
anymore.

Why:

  Persisting ephemeral process handles to SQLite forced reconcile to
  treat "running with a stale PID" as a first-class case and mix it
  with real state transitions. The schema described what we last
  observed, not what the VM is. Every time the observation model
  shifted (tap pool, DM naming, pgrep fallback) the reconcile logic
  grew a new branch. Splitting lets each layer own what it's good at:
  durable records describe intent, in-memory cache + scratch file
  describe momentary reality.

Shape:

  - `model.VMHandles` = PID, TapDevice, BaseLoop, COWLoop, DMName,
    DMDev. Never in SQLite.
  - `VMRuntime` keeps: State, GuestIP, APISockPath, VSockPath,
    VSockCID, LogPath, MetricsPath, DNSName, VMDir, SystemOverlay,
    WorkDiskPath, LastError. All durable or deterministic.
  - `handleCache` on `*Daemon` — mutex-guarded map + scratch-file
    plumbing (`writeHandlesFile` / `readHandlesFile` /
    `rediscoverHandles`). See `internal/daemon/vm_handles.go`.
  - `d.vmAlive(vm)` replaces the 20+ inline
    `vm.State==Running && ProcessRunning(vm.Runtime.PID, apiSock)`
    spreads. Single source of truth for liveness.
  - Startup reconcile: per running VM, load the scratch file, pgrep
    the api sock, either keep (cache seeded from scratch) or demote
    to stopped (scratch handles passed to cleanupRuntime first so DM
    / loops / tap actually get torn down).

Verification:

  - `go test ./...` green.
  - Live: `banger vm run --name handles-test -- cat /etc/hostname`
    starts; `handles.json` appears in VMDir with the expected PID,
    tap, loops, DM.
  - `kill -9 $(pgrep bangerd)` while the VM is running, re-invoke the
    CLI, daemon auto-starts, reconcile recognises the VM as alive,
    `banger vm ssh` still connects, `banger vm delete` cleans up.

Tests added:

  - vm_handles_test.go: scratch-file roundtrip, missing/corrupt file
    behaviour, cache concurrency, rediscoverHandles prefers pgrep
    over scratch, returns scratch contents even when process is
    dead (so cleanup can tear down kernel state).
  - vm_test.go: reconcile test rewritten to exercise the new flow
    (write scratch → reconcile reads it → verifies process is gone →
    issues dmsetup/losetup teardown).

ARCHITECTURE.md updated; `handles` added to Daemon field docs.
2026-04-19 14:18:13 -03:00

297 lines
10 KiB
Go

package model
import (
"crypto/rand"
"encoding/hex"
"errors"
"fmt"
"strconv"
"strings"
"time"
)
const (
DefaultBridgeName = "br-fc"
DefaultBridgeIP = "172.16.0.1"
DefaultCIDR = "24"
DefaultDNS = "1.1.1.1"
DefaultSystemOverlaySize = 8 * 1024 * 1024 * 1024
DefaultWorkDiskSize = 8 * 1024 * 1024 * 1024
DefaultMemoryMiB = 2048
DefaultVCPUCount = 2
DefaultStatsPollInterval = 10 * time.Second
DefaultStaleSweepInterval = 1 * time.Minute
DefaultMetricsPollInterval = 15 * time.Second
MaxDiskBytes int64 = 128 * 1024 * 1024 * 1024
)
type VMState string
const (
VMStateCreated VMState = "created"
VMStateRunning VMState = "running"
VMStateStopped VMState = "stopped"
VMStateError VMState = "error"
)
type GuestSessionStatus string
const (
GuestSessionStatusStarting GuestSessionStatus = "starting"
GuestSessionStatusRunning GuestSessionStatus = "running"
GuestSessionStatusExited GuestSessionStatus = "exited"
GuestSessionStatusFailed GuestSessionStatus = "failed"
GuestSessionStatusStopping GuestSessionStatus = "stopping"
)
type GuestSessionStdinMode string
const (
GuestSessionStdinClosed GuestSessionStdinMode = "closed"
GuestSessionStdinPipe GuestSessionStdinMode = "pipe"
)
type DaemonConfig struct {
LogLevel string
WebListenAddr string
FirecrackerBin string
SSHKeyPath string
AutoStopStaleAfter time.Duration
StatsPollInterval time.Duration
MetricsPollInterval time.Duration
BridgeName string
BridgeIP string
CIDR string
TapPoolSize int
DefaultDNS string
DefaultImageName string
FileSync []FileSyncEntry
VMDefaults VMDefaultsOverride
}
// FileSyncEntry is a user-declared host→guest file or directory copy
// applied to each VM's work disk at vm create time. Host is expanded
// against the host user's $HOME for "~/..."; Guest is expanded
// against /root (banger VMs are single-user root). If the host path
// is a directory, it's copied recursively; if it's a file, it's
// copied as a file. Missing host paths are a soft skip (warned, not
// fatal). Mode defaults to 0600 for files and 0755 for directories.
type FileSyncEntry struct {
Host string
Guest string
Mode string
}
type Image struct {
ID string `json:"id"`
Name string `json:"name"`
Managed bool `json:"managed"`
ArtifactDir string `json:"artifact_dir,omitempty"`
RootfsPath string `json:"rootfs_path"`
WorkSeedPath string `json:"work_seed_path,omitempty"`
KernelPath string `json:"kernel_path"`
InitrdPath string `json:"initrd_path,omitempty"`
ModulesDir string `json:"modules_dir,omitempty"`
BuildSize string `json:"build_size,omitempty"`
SeededSSHPublicKeyFingerprint string `json:"seeded_ssh_public_key_fingerprint,omitempty"`
Docker bool `json:"docker"`
CreatedAt time.Time `json:"created_at"`
UpdatedAt time.Time `json:"updated_at"`
}
type VMSpec struct {
VCPUCount int `json:"vcpu_count"`
MemoryMiB int `json:"memory_mib"`
SystemOverlaySizeByte int64 `json:"system_overlay_size_bytes"`
WorkDiskSizeBytes int64 `json:"work_disk_size_bytes"`
NATEnabled bool `json:"nat_enabled"`
}
// VMRuntime holds the durable runtime state that the daemon needs
// to reach a VM: identity, declared state, and deterministic derived
// paths. Transient kernel/process handles (PID, tap, loop devices,
// dm-snapshot names) live on VMHandles, NOT here — the daemon keeps
// them in an in-memory cache backed by a per-VM handles.json scratch
// file, so a daemon restart rebuilds them from OS state rather than
// trusting whatever was last written into a SQLite column.
//
// Everything in VMRuntime is safe to persist: the paths are
// deterministic from (VM ID, layout) and survive restart unchanged;
// GuestIP and DNSName are assigned at create time and never move;
// LastError carries the last failure message for debugging. State
// mirrors VMRecord.State.
type VMRuntime struct {
State VMState `json:"state"`
GuestIP string `json:"guest_ip"`
APISockPath string `json:"api_sock_path,omitempty"`
VSockPath string `json:"vsock_path,omitempty"`
VSockCID uint32 `json:"vsock_cid,omitempty"`
LogPath string `json:"log_path,omitempty"`
MetricsPath string `json:"metrics_path,omitempty"`
DNSName string `json:"dns_name,omitempty"`
VMDir string `json:"vm_dir"`
SystemOverlay string `json:"system_overlay_path"`
WorkDiskPath string `json:"work_disk_path"`
LastError string `json:"last_error,omitempty"`
}
type VMStats struct {
CollectedAt time.Time `json:"collected_at,omitempty"`
CPUPercent float64 `json:"cpu_percent,omitempty"`
RSSBytes int64 `json:"rss_bytes,omitempty"`
VSZBytes int64 `json:"vsz_bytes,omitempty"`
SystemOverlayBytes int64 `json:"system_overlay_bytes,omitempty"`
WorkDiskBytes int64 `json:"work_disk_bytes,omitempty"`
MetricsRaw map[string]any `json:"metrics_raw,omitempty"`
}
type VMRecord struct {
ID string `json:"id"`
Name string `json:"name"`
ImageID string `json:"image_id"`
State VMState `json:"state"`
CreatedAt time.Time `json:"created_at"`
UpdatedAt time.Time `json:"updated_at"`
LastTouchedAt time.Time `json:"last_touched_at"`
Spec VMSpec `json:"spec"`
Runtime VMRuntime `json:"runtime"`
Stats VMStats `json:"stats"`
}
type VMCreateRequest struct {
Name string
ImageName string
VCPUCount int
MemoryMiB int
SystemOverlaySizeByte int64
WorkDiskSizeBytes int64
NATEnabled bool
NoStart bool
}
type VMSetRequest struct {
IDOrName string
VCPUCount *int
MemoryMiB *int
WorkDiskSizeBytes *int64
NATEnabled *bool
}
type GuestSession struct {
ID string `json:"id"`
VMID string `json:"vm_id"`
Name string `json:"name"`
Backend string `json:"backend"`
AttachBackend string `json:"attach_backend,omitempty"`
AttachMode string `json:"attach_mode,omitempty"`
Command string `json:"command"`
Args []string `json:"args,omitempty"`
CWD string `json:"cwd,omitempty"`
Env map[string]string `json:"env,omitempty"`
StdinMode GuestSessionStdinMode `json:"stdin_mode,omitempty"`
Status GuestSessionStatus `json:"status"`
ExitCode *int `json:"exit_code,omitempty"`
GuestPID int `json:"guest_pid,omitempty"`
GuestStateDir string `json:"guest_state_dir,omitempty"`
StdoutLogPath string `json:"stdout_log_path,omitempty"`
StderrLogPath string `json:"stderr_log_path,omitempty"`
Tags map[string]string `json:"tags,omitempty"`
LastError string `json:"last_error,omitempty"`
Attachable bool `json:"attachable"`
Reattachable bool `json:"reattachable"`
LaunchStage string `json:"launch_stage,omitempty"`
LaunchMessage string `json:"launch_message,omitempty"`
LaunchRawLog string `json:"launch_raw_log,omitempty"`
CreatedAt time.Time `json:"created_at"`
StartedAt time.Time `json:"started_at,omitempty"`
UpdatedAt time.Time `json:"updated_at"`
EndedAt time.Time `json:"ended_at,omitempty"`
}
type WorkspacePrepareMode string
const (
WorkspacePrepareModeShallowOverlay WorkspacePrepareMode = "shallow_overlay"
WorkspacePrepareModeFullCopy WorkspacePrepareMode = "full_copy"
WorkspacePrepareModeMetadataOnly WorkspacePrepareMode = "metadata_only"
)
type WorkspacePrepareResult struct {
VMID string `json:"vm_id"`
SourcePath string `json:"source_path"`
RepoRoot string `json:"repo_root"`
RepoName string `json:"repo_name"`
GuestPath string `json:"guest_path"`
Mode WorkspacePrepareMode `json:"mode"`
ReadOnly bool `json:"readonly"`
HeadCommit string `json:"head_commit,omitempty"`
CurrentBranch string `json:"current_branch,omitempty"`
BranchName string `json:"branch_name,omitempty"`
BaseCommit string `json:"base_commit,omitempty"`
PreparedAt time.Time `json:"prepared_at"`
}
func Now() time.Time {
return time.Now().UTC().Truncate(time.Second)
}
func NewID() (string, error) {
buf := make([]byte, 32)
if _, err := rand.Read(buf); err != nil {
return "", err
}
return hex.EncodeToString(buf), nil
}
func ParseSize(raw string) (int64, error) {
if raw == "" {
return 0, errors.New("size is required")
}
raw = strings.TrimSpace(strings.ToUpper(raw))
if raw == "" {
return 0, errors.New("size is required")
}
unit := raw[len(raw)-1]
multiplier := int64(1024 * 1024)
number := raw
switch unit {
case 'K':
multiplier = 1024
number = raw[:len(raw)-1]
case 'M':
multiplier = 1024 * 1024
number = raw[:len(raw)-1]
case 'G':
multiplier = 1024 * 1024 * 1024
number = raw[:len(raw)-1]
default:
if unit < '0' || unit > '9' {
return 0, fmt.Errorf("unsupported size suffix: %q", string(unit))
}
}
value, err := strconv.ParseInt(number, 10, 64)
if err != nil {
return 0, fmt.Errorf("parse size %q: %w", raw, err)
}
result := value * multiplier
if result <= 0 {
return 0, fmt.Errorf("size must be positive: %q", raw)
}
if result > MaxDiskBytes {
return 0, fmt.Errorf("size exceeds max of %d bytes", MaxDiskBytes)
}
return result, nil
}
func FormatSizeBytes(bytes int64) string {
switch {
case bytes%(1024*1024*1024) == 0:
return fmt.Sprintf("%dG", bytes/(1024*1024*1024))
case bytes%(1024*1024) == 0:
return fmt.Sprintf("%dM", bytes/(1024*1024))
case bytes%1024 == 0:
return fmt.Sprintf("%dK", bytes/1024)
default:
return strconv.FormatInt(bytes, 10)
}
}