Files
ctask/internal/session/run.go
T

342 lines
12 KiB
Go

package session
import (
"fmt"
"os"
"os/exec"
"path/filepath"
"time"
"github.com/warrenronsiek/ctask/internal/lockfile"
"github.com/warrenronsiek/ctask/internal/shell"
"github.com/warrenronsiek/ctask/internal/workspace"
)
// LaunchOpts configures a session launch.
type LaunchOpts struct {
WsDir string
EnvVars map[string]string
Agent string
Mode string
Slug string
Shell bool // true = interactive shell, false = agent
// LaunchDir is the workspace-relative launch directory (v0.5). Empty for
// tasks and pre-v0.5 projects. When set, Run resolves the absolute path
// via workspace.ResolveLaunch and uses it as the child's working dir;
// a security violation (absolute path or .. escape) aborts the session.
LaunchDir string
// SessionMode is "direct" (default) or "persistent". In persistent mode,
// Run dispatches to shell.ExecTmuxAgent / ExecTmuxShell. The heartbeat
// continues throughout. handleProvisional is bypassed via
// shouldRunProvisional.
SessionMode string
// SessionName is the deterministic tmux session name (computed by the
// cmd-layer dispatcher via session.SessionName). Required when
// SessionMode == "persistent"; empty otherwise.
SessionName string
// Category mirrors Workspace.Meta.Category for symmetry; not directly
// consumed by Run today but populated by the dispatcher for any future
// session-name regeneration paths and for clarity in logs.
Category string
// TmuxPath is the validated tmux binary path returned by
// preflightPersistentEntry / shell.LookupTmux. Required when
// SessionMode == "persistent"; empty otherwise. Run does NOT call
// exec.LookPath itself — the cmd-layer preflight is the single source
// of truth.
TmuxPath string
// Force suppresses both the active-session warning (Layer 1) and the
// stale-workspace warning (Layer 3). It does NOT disable the metadata
// write lock or the session summary. Used for scripted/automated runs.
Force bool
// NewlyCreated signals that this invocation just created WsDir (via
// `ctask new`). When true and the session's manifest diff is empty, the
// workspace is treated as provisional and removed on exit — see
// handleProvisional. Set to false by resume/open/last.
NewlyCreated bool
}
// manifestStartPath returns the path to the start manifest file.
func manifestStartPath(wsDir string) string {
return filepath.Join(wsDir, ".ctask", "manifest-start.json")
}
// ctaskWriteLockPath returns the path to the workspace write lock file.
func ctaskWriteLockPath(wsDir string) string {
return filepath.Join(wsDir, ".ctask", "write.lock")
}
const (
sessionWriteLockTimeout = 2 * time.Second
sessionWriteLockStaleAfter = 10 * time.Second
)
// Run launches an agent or shell session. It sequences the full v0.4
// concurrency-protection lifecycle:
//
// 1. Layer 3: stale-workspace detection (warn if files changed outside a
// ctask session; skipped if Force is true).
// 2. Layer 1: active-session lease check (warn or auto-clean stale;
// skipped if Force is true).
// 3. Layer 2: write lock taken to install the new lease (unless coexisting
// with an already-active lease, in which case no lease is written).
// 4. Start manifest capture + write.
// 5. Launch context banner (Layer 4 — prints the last-session summary).
// 6. Heartbeat goroutine starts (Layer 1) when we own a lease.
// 7. Agent/shell runs to completion.
// 8. Heartbeat stops.
// 9. End manifest + diff.
// 10. Write lock taken to append log, write summary (Layer 4), remove
// lease (Layer 1), remove start manifest.
//
// Returns the child process's error (for exit-code propagation).
func Run(opts LaunchOpts) error {
// ---- Preflight (Layers 3 + 1) ----
preflight, err := PreflightFull(PreflightOpts{
WsDir: opts.WsDir,
Force: opts.Force,
In: os.Stdin,
Out: os.Stderr,
})
if err != nil {
fmt.Fprintf(os.Stderr, "[ctask] Warning: preflight check failed: %v\n", err)
// Continue anyway — preflight errors must never block the session.
}
if !preflight.Proceed {
return nil
}
startTime := time.Now().UTC().Truncate(time.Second)
// ---- Install a lease unless we're coexisting with an active one ----
// Lease creation is "important but non-fatal": if the lock times out,
// the session runs without concurrency protection; make that visible.
leasePath := LeasePath(opts.WsDir)
ownLease := !preflight.ActiveLeaseFound
if ownLease {
lease := NewLease(startTime, opts.Agent, opts.Mode)
skipped, lockErr := lockfile.WithLock(
ctaskWriteLockPath(opts.WsDir),
sessionWriteLockTimeout, sessionWriteLockStaleAfter,
func() error { return WriteLease(leasePath, lease) },
)
if lockErr != nil {
fmt.Fprintf(os.Stderr, "[ctask] Warning: could not write session lease: %v; this session will not be visible to concurrent ctask processes\n", lockErr)
ownLease = false
}
if skipped {
fmt.Fprintf(os.Stderr, "[ctask] Warning: could not acquire metadata lock, skipping write to %s; this session will not be visible to concurrent ctask processes\n", leasePath)
ownLease = false
}
}
// ---- Start manifest (important but non-fatal) ----
startManifest, err := CaptureManifest(opts.WsDir)
if err != nil {
fmt.Fprintf(os.Stderr, "[ctask] warning: failed to capture start manifest: %v; end-of-session diff will be skipped\n", err)
}
if startManifest != nil {
mPath := manifestStartPath(opts.WsDir)
skipped, lockErr := lockfile.WithLock(
ctaskWriteLockPath(opts.WsDir),
sessionWriteLockTimeout, sessionWriteLockStaleAfter,
func() error { return WriteManifest(mPath, startManifest) },
)
if skipped {
fmt.Fprintf(os.Stderr, "[ctask] Warning: could not acquire metadata lock, skipping write to %s; end-of-session diff will be skipped\n", mPath)
startManifest = nil
} else if lockErr != nil {
fmt.Fprintf(os.Stderr, "[ctask] Warning: could not write start manifest: %v\n", lockErr)
startManifest = nil
}
}
// ---- Launch context banner (Layer 4 — best-effort read) ----
if summary, err := ReadSummary(SummaryPath(opts.WsDir)); err == nil && summary != nil {
fmt.Fprint(os.Stderr, FormatLaunchContext(summary))
}
// ---- Heartbeat (Layer 1) ----
var hb *Heartbeat
if ownLease {
hb = StartHeartbeat(leasePath, HeartbeatInterval)
}
// ---- Resolve launch directory (v0.5) ----
// Security violations (absolute path, ..-escape) abort the session
// before we hand control to the child. Missing/non-dir falls back to
// wsDir with a warning.
launchAbs, launchWarn, launchErr := workspace.ResolveLaunch(opts.WsDir, opts.LaunchDir)
if launchErr != nil {
return fmt.Errorf("resolving launch_dir: %w", launchErr)
}
if launchWarn != "" {
fmt.Fprintln(os.Stderr, launchWarn)
}
// ---- Run the child ----
var childErr error
switch {
case opts.SessionMode == "persistent":
// Persistent mode: tmux owns the foreground process. Banner prints
// from here (tmux paints over it within ~50ms of attach — accepted).
if !opts.Shell {
for _, line := range shell.BannerLines(opts.Mode, opts.Slug, opts.WsDir, opts.LaunchDir) {
fmt.Println(line)
}
}
if opts.TmuxPath == "" {
if hb != nil {
hb.Stop()
}
return fmt.Errorf("internal error: LaunchOpts.TmuxPath is empty in persistent mode")
}
if opts.SessionName == "" {
if hb != nil {
hb.Stop()
}
return fmt.Errorf("internal error: LaunchOpts.SessionName is empty in persistent mode")
}
if opts.Shell {
childErr = shell.ExecTmuxShell(opts.TmuxPath, opts.SessionName, launchAbs, opts.EnvVars)
} else {
childErr = shell.ExecTmuxAgent(opts.TmuxPath, opts.SessionName, launchAbs, opts.EnvVars, opts.Agent)
}
case opts.Shell:
childErr = shell.ExecShell(launchAbs, opts.EnvVars, opts.Slug, opts.Mode)
default:
for _, line := range shell.BannerLines(opts.Mode, opts.Slug, opts.WsDir, opts.LaunchDir) {
fmt.Println(line)
}
childErr = shell.ExecAgent(opts.Agent, launchAbs, opts.EnvVars)
}
if hb != nil {
hb.Stop()
}
// ---- Provisional-workspace cleanup ----
// If `ctask new` launched this session, the child exited non-zero
// (canceled before real work), and no files changed, remove the workspace
// entirely and skip finalize. A zero child exit means the user entered
// the agent and exited normally — those workspaces are preserved even
// with an empty diff. Persistent (tmux) mode bypasses this gate via
// shouldRunProvisional.
if shouldRunProvisional(opts) && handleProvisional(opts, startManifest, childExitCode(childErr)) {
return childErr
}
// ---- Post-session: manifest + summary + cleanup ----
endTime := time.Now().UTC().Truncate(time.Second)
if startManifest != nil {
if err := finalize(opts, startManifest, startTime, endTime, ownLease); err != nil {
fmt.Fprintf(os.Stderr, "[ctask] warning: session finalize failed: %v\n", err)
// Leave manifest-start.json for debugging on failure.
}
}
return childErr
}
// shouldRunProvisional reports whether the provisional-workspace cleanup
// gate should run for the given opts. Persistent mode unconditionally
// disables the gate (see v0.5.3-spec.md §7); direct mode runs the gate
// only when the workspace was created by this invocation.
func shouldRunProvisional(opts LaunchOpts) bool {
return opts.SessionMode != "persistent" && opts.NewlyCreated
}
// childExitCode extracts the exit code from the error returned by cmd.Run().
// Returns 0 when err is nil (clean exit). Returns the reported code for
// *exec.ExitError. Returns -1 for any other error (agent not found, OS-level
// failure) so provisional cleanup still kicks in — the child never ran.
func childExitCode(err error) int {
if err == nil {
return 0
}
if ee, ok := err.(*exec.ExitError); ok {
return ee.ExitCode()
}
return -1
}
// finalize runs all end-of-session metadata writes under one write-lock
// acquisition: session log append (best-effort), last-session-summary.json
// (best-effort), lease removal (best-effort, if we owned it), and
// manifest-start.json cleanup.
func finalize(opts LaunchOpts, startManifest *Manifest, startTime, endTime time.Time, ownLease bool) error {
endManifest, err := CaptureManifest(opts.WsDir)
if err != nil {
return fmt.Errorf("capturing end manifest: %w", err)
}
diff := DiffManifests(startManifest, endManifest)
agent := opts.Agent
if opts.Shell {
agent = "shell"
}
info := &SessionInfo{
Agent: agent,
Mode: opts.Mode,
StartTime: startTime,
EndTime: endTime,
Diff: diff,
}
// Pull the session ID from the lease (if we own one) so the summary
// references the same ID used during the session. Fall back to a
// constructed ID to keep the summary self-describing when leaseless.
sessionID := NewSessionID(currentHostname(), os.Getpid(), startTime)
if ownLease {
if l, err := ReadLease(LeasePath(opts.WsDir)); err == nil && l != nil {
sessionID = l.SessionID
}
}
summary := SummarizeFromDiff(
sessionID, currentHostname(), agent, opts.Mode,
startTime, endTime, diff, endManifest,
)
if opts.SessionMode == "persistent" {
summary.EndReason = "tmux_session_ended"
summary.DetectedVia = "polling"
summary.SessionOwnership = "created"
} else {
summary.EndReason = "child_exited"
summary.DetectedVia = "child_exit"
}
skipped, lockErr := lockfile.WithLock(
ctaskWriteLockPath(opts.WsDir),
sessionWriteLockTimeout, sessionWriteLockStaleAfter,
func() error {
if err := AppendSessionLog(opts.WsDir, info); err != nil {
fmt.Fprintf(os.Stderr, "[ctask] warning: append session log failed: %v\n", err)
}
if err := WriteSummary(SummaryPath(opts.WsDir), summary); err != nil {
return fmt.Errorf("write summary: %w", err)
}
if ownLease {
if rmErr := os.Remove(LeasePath(opts.WsDir)); rmErr != nil && !os.IsNotExist(rmErr) {
fmt.Fprintf(os.Stderr, "[ctask] warning: could not remove lease: %v\n", rmErr)
}
}
if rmErr := os.Remove(manifestStartPath(opts.WsDir)); rmErr != nil && !os.IsNotExist(rmErr) {
fmt.Fprintf(os.Stderr, "[ctask] warning: could not remove start manifest: %v\n", rmErr)
}
return nil
},
)
if skipped {
fmt.Fprintf(os.Stderr, "[ctask] Warning: could not acquire metadata lock, skipping session-end writes (summary and lease cleanup)\n")
return nil
}
return lockErr
}