molecule-cli/internal/cmd/connect.go
Hongming Wang 3a6a7eb495 feat(connect): M1.1 — Backend interface + connect skeleton + mock backend
First step toward `molecule connect <id>` — the out-of-box external-
runtime workspace connector specified in RFC #10.

What's in this PR (foundational, ~300 LOC of code + matching tests):

- `internal/backends.Backend` — the seam every concrete handler
  implements: HandleA2A(ctx, Request) → Response, Close(). Two methods,
  no inheritance, no surprise side effects. Concurrency-safe by
  contract (poll dispatch may parallelise).
- Request/Response/Part/Config types — lossless JSON-RPC mirror so
  backends can re-issue downstream without re-parsing.
- Compile-time registry — `Register("name", factory)` from each
  backend's init(); `Build(name, cfg)` selects at runtime. Panics
  on duplicate registration so drift fails loudly at startup, not
  on first message.
- `mock` backend — single-template echo for CI smoke + tests + demos.
  `--backend-opt reply="<template>"` with `%s` for inbound text.
- `molecule connect <workspace-id>` cobra command — flag surface,
  validation, --dry-run for smoke. Loops (heartbeat, activity poll,
  dispatch) land in M1.2 in internal/connect/.

Coverage:
- Registry: duplicate-name panic, empty-name panic, nil-factory panic,
  Build unknown-name error includes registered list.
- Mock: default template, custom template, text-part concatenation,
  Final=true on terminal response.
- Connect: --backend-opt KEY=VALUE parser (incl. value with =),
  flag validation (missing token, bad mode, bad opt, unknown
  backend), --dry-run happy path.

All tests pass under -race.

Out of scope (subsequent M1 PRs):
- M1.2: heartbeat + activity poll loops in internal/connect/
- M1.3: claude-code backend (wraps molecule-mcp-claude-channel)
- M1.4: GoReleaser tag-triggered release.yml workflow

RFC: https://github.com/Molecule-AI/molecule-cli/issues/10

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-30 02:05:12 -07:00

145 lines
5.3 KiB
Go

package cmd
import (
"context"
"fmt"
"os"
"os/signal"
"strings"
"syscall"
"github.com/Molecule-AI/molecule-cli/internal/backends"
_ "github.com/Molecule-AI/molecule-cli/internal/backends/mock" // register backend
"github.com/spf13/cobra"
)
// ---------------------------------------------------------------------------
// molecule connect — bridge an external-runtime workspace to a local backend.
//
// The full M1+ design lives in the RFC at
// https://github.com/Molecule-AI/molecule-cli/issues/10. This file owns the
// command surface; the wiring (heartbeat, activity poll, dispatch) lands in
// internal/connect/ in subsequent PRs.
// ---------------------------------------------------------------------------
var connectFlags struct {
backend string
backendOpts []string // KEY=VALUE pairs, repeatable
token string
mode string // "poll" (default) | "push"
intervalMs int // poll cadence, milliseconds
sinceSecs int // initial activity-cursor lookback
dryRun bool // build backend + print summary, do not start loops
}
var connectCmd = &cobra.Command{
Use: "connect <workspace-id>",
Short: "Bridge an external workspace to a local backend (Claude Code, exec, mock, ...)",
Long: `connect attaches the calling process to an external-runtime workspace.
Inbound A2A messages routed to the workspace are dispatched to the
selected --backend. The default backend is "claude-code" (bridges into
a running Claude Code session via the channel plugin); use "mock" for
CI smoke and "exec" for arbitrary shell handlers.
Authentication: the per-workspace token from the create response is
read from --token or the MOLECULE_WORKSPACE_TOKEN env var. The
platform URL is read from --api-url or MOLECULE_API_URL.
Mode: poll (default) is the no-public-URL path — the CLI long-polls
the platform for inbound activity. push requires the local box to be
reachable from the platform (public HTTPS); use only when running on
a server with an inbound URL.
Examples:
# Default: bridge into a running Claude Code session
molecule connect ws_01HF2K... --token $WS_TOKEN
# CI smoke / demo — replies are deterministic
molecule connect ws_01HF2K... --backend mock \
--backend-opt reply="echo: %s"
# Arbitrary shell handler
molecule connect ws_01HF2K... --backend exec \
--backend-opt cmd="python myhandler.py"
See full design: https://github.com/Molecule-AI/molecule-cli/issues/10`,
Args: cobra.ExactArgs(1),
RunE: runConnect,
}
func init() {
connectCmd.Flags().StringVar(&connectFlags.backend, "backend", "claude-code",
fmt.Sprintf("Backend that handles inbound A2A messages (registered: %s)",
strings.Join(backends.Names(), ", ")))
connectCmd.Flags().StringArrayVar(&connectFlags.backendOpts, "backend-opt", nil,
"Backend-specific option, KEY=VALUE (repeatable)")
connectCmd.Flags().StringVar(&connectFlags.token, "token",
envOr("MOLECULE_WORKSPACE_TOKEN", ""),
"Workspace auth token (env: MOLECULE_WORKSPACE_TOKEN)")
connectCmd.Flags().StringVar(&connectFlags.mode, "mode", "poll",
"Delivery mode: poll (no public URL needed) | push")
connectCmd.Flags().IntVar(&connectFlags.intervalMs, "interval-ms", 1000,
"Poll-mode interval between activity fetches, in milliseconds")
connectCmd.Flags().IntVar(&connectFlags.sinceSecs, "since-secs", 30,
"Poll-mode initial cursor lookback, in seconds")
connectCmd.Flags().BoolVar(&connectFlags.dryRun, "dry-run", false,
"Build the backend and print the connection summary, but do not start loops")
}
func runConnect(_ *cobra.Command, args []string) error {
workspaceID := strings.TrimSpace(args[0])
if workspaceID == "" {
return &exitError{code: 2, msg: "connect: workspace-id is required"}
}
if connectFlags.token == "" {
return &exitError{code: 2, msg: "connect: --token (or MOLECULE_WORKSPACE_TOKEN) is required"}
}
if connectFlags.mode != "poll" && connectFlags.mode != "push" {
return &exitError{code: 2, msg: "connect: --mode must be poll or push"}
}
cfg, err := parseBackendOpts(connectFlags.backendOpts)
if err != nil {
return &exitError{code: 2, msg: err.Error()}
}
backend, err := backends.Build(connectFlags.backend, cfg)
if err != nil {
return &exitError{code: 2, msg: err.Error()}
}
fmt.Fprintf(os.Stderr, "molecule connect: workspace=%s backend=%s mode=%s api=%s\n",
workspaceID, connectFlags.backend, connectFlags.mode, apiURL)
if connectFlags.dryRun {
fmt.Fprintln(os.Stderr, "molecule connect: --dry-run; backend built ok, not starting loops")
return backend.Close()
}
// Loops (heartbeat + activity poll + dispatch) land in internal/connect
// in PR M1.2. For M1.1 we wire signal handling so the command exits
// cleanly when invoked in --dry-run by tests, and so future loops
// inherit context cancellation.
ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
defer cancel()
<-ctx.Done()
fmt.Fprintln(os.Stderr, "molecule connect: shutting down")
return backend.Close()
}
// parseBackendOpts converts repeated KEY=VALUE flags into a Config map.
func parseBackendOpts(opts []string) (backends.Config, error) {
cfg := backends.Config{}
for _, opt := range opts {
k, v, ok := strings.Cut(opt, "=")
if !ok || k == "" {
return nil, fmt.Errorf("--backend-opt: %q is not KEY=VALUE", opt)
}
cfg[k] = v
}
return cfg, nil
}