Changeset 0.29.0 (#195)

server/sandbox/runner.go

@@ -0,0 +1,131 @@
+// Package sandbox — runner.go
+//
+// v0.29.0 CS3: Runner loads a package's Starlark script, assembles
+// the module set based on granted permissions, and executes it.
+//
+// The runner is the bridge between the package/permission system
+// and the sandboxed Starlark interpreter.
+package sandbox
+
+import (
+	"context"
+	"fmt"
+	"log"
+
+	"go.starlark.net/starlark"
+
+	"git.gobha.me/xcaliber/chat-switchboard/models"
+	"git.gobha.me/xcaliber/chat-switchboard/store"
+)
+
+// Runner executes Starlark package scripts with permission-gated modules.
+type Runner struct {
+	sandbox  *Sandbox
+	stores   store.Stores
+	notifier NotificationSender // nil = notifications module unavailable
+}
+
+// NewRunner creates a runner with the given sandbox and dependencies.
+func NewRunner(sb *Sandbox, stores store.Stores) *Runner {
+	return &Runner{
+		sandbox: sb,
+		stores:  stores,
+	}
+}
+
+// SetNotifier attaches the notification sender for the notifications module.
+func (r *Runner) SetNotifier(n NotificationSender) {
+	r.notifier = n
+}
+
+// ExecPackage loads a package's script from its manifest and executes it
+// with modules gated by the package's granted permissions.
+//
+// Returns the script's globals (which may contain callable entry points
+// like on_pre_completion, on_run, etc.) and any captured print output.
+func (r *Runner) ExecPackage(ctx context.Context, pkg *store.PackageRegistration) (*Result, error) {
+	// Only active starlark packages can execute
+	if pkg.Status != models.PackageStatusActive {
+		return nil, fmt.Errorf("package %q is %s, not active", pkg.ID, pkg.Status)
+	}
+	if pkg.Tier != models.ExtTierStarlark {
+		return nil, fmt.Errorf("package %q is tier %s, not starlark", pkg.ID, pkg.Tier)
+	}
+
+	// Extract script from manifest
+	script, ok := pkg.Manifest["_starlark_script"].(string)
+	if !ok || script == "" {
+		return nil, fmt.Errorf("package %q has no _starlark_script in manifest", pkg.ID)
+	}
+
+	// Build modules based on granted permissions
+	modules, err := r.buildModules(ctx, pkg.ID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to build modules for %q: %w", pkg.ID, err)
+	}
+
+	log.Printf("  🔧 runner: exec %s (%d modules granted)", pkg.ID, len(modules))
+
+	return r.sandbox.Exec(ctx, pkg.ID+".star", script, modules)
+}
+
+// CallEntryPoint executes a package script and calls a named function.
+// This is the standard pattern for event-driven extensions:
+//   1. Exec the script (defines functions)
+//   2. Find the named entry point in globals
+//   3. Call it with the provided arguments
+//
+// Returns the function's return value and captured output.
+func (r *Runner) CallEntryPoint(ctx context.Context, pkg *store.PackageRegistration, entryPoint string, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, string, error) {
+	result, err := r.ExecPackage(ctx, pkg)
+	if err != nil {
+		return nil, "", err
+	}
+
+	fn, ok := result.Globals[entryPoint]
+	if !ok {
+		return nil, result.Output, fmt.Errorf("package %q has no %s function", pkg.ID, entryPoint)
+	}
+
+	callable, ok := fn.(starlark.Callable)
+	if !ok {
+		return nil, result.Output, fmt.Errorf("package %q: %s is not callable", pkg.ID, entryPoint)
+	}
+
+	val, callOutput, err := r.sandbox.Call(ctx, callable, args, kwargs)
+	return val, result.Output + callOutput, err
+}
+
+// buildModules assembles the module map based on granted permissions.
+func (r *Runner) buildModules(ctx context.Context, packageID string) (map[string]starlark.Value, error) {
+	if r.stores.ExtPermissions == nil {
+		return nil, nil
+	}
+
+	granted, err := r.stores.ExtPermissions.GrantedForPackage(ctx, packageID)
+	if err != nil {
+		return nil, err
+	}
+
+	modules := make(map[string]starlark.Value)
+
+	for _, perm := range granted {
+		switch perm {
+		case models.ExtPermSecretsRead:
+			modules["secrets"] = BuildSecretsModule(ctx, r.stores, packageID)
+
+		case models.ExtPermNotificationsSend:
+			if r.notifier != nil {
+				modules["notifications"] = BuildNotificationsModule(ctx, r.notifier, packageID)
+			}
+
+		// Future permissions (CS4+):
+		// case models.ExtPermDBRead, models.ExtPermDBWrite:
+		//     modules["db"] = BuildDBModule(...)
+		// case models.ExtPermAPIHTTP:
+		//     modules["http"] = BuildHTTPModule(...)
+		}
+	}
+
+	return modules, nil
+}