Files
kandev/apps/backend/pkg/pluginsdk/plugin.go
T
2026-08-12 20:25:13 +01:00

92 lines
3.3 KiB
Go

package pluginsdk
import (
"context"
"sync"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/status"
)
// Plugin is the interface a plugin author implements. It is delivered RPCs
// from kandev over the go-plugin gRPC transport (§3 of
// docs/plans/plugins/GRPC-CONTRACT.md): DeliverEvent -> OnEvent,
// HandleWebhook -> HandleWebhook.
type Plugin interface {
// OnEvent handles a single bus event delivery. A non-nil error causes
// kandev's delivery subsystem to retry per §5 (3 retries, 5s/15s/45s).
OnEvent(ctx context.Context, e *Event) error
// HandleWebhook handles an inbound webhook relayed by kandev's
// POST /api/plugins/{id}/webhooks/{key} endpoint.
HandleWebhook(ctx context.Context, req *WebhookRequest) (*WebhookResponse, error)
}
// AgentToolPlugin is an optional extension implemented by plugins that
// declare agent_tools in their manifest. Keeping it separate from Plugin
// preserves source compatibility for existing plugins.
type AgentToolPlugin interface {
InvokeAgentTool(context.Context, *AgentToolRequest) (*AgentToolResult, error)
}
// HostSetter is implemented by Plugin values that want Serve to inject the
// Host once the broker connection back to kandev is established (see the
// "Host injection" section of the serve.go file header). UnimplementedPlugin
// implements this, so embedding it is the easiest way to opt in.
type HostSetter interface {
SetHost(Host)
}
// UnimplementedPlugin is an embeddable no-op base for Plugin. Authors that
// only care about one or two RPCs embed this and override the rest. It also
// implements HostSetter, storing the injected Host for retrieval via Host().
//
// SetHost is called from a background goroutine (see the GRPCPlugin doc
// comment in serve.go for why), so access to the stored Host is
// mutex-guarded — Host() may be called concurrently with SetHost from
// another goroutine.
type UnimplementedPlugin struct {
mu sync.RWMutex
host Host
}
var (
_ Plugin = (*UnimplementedPlugin)(nil)
_ HostSetter = (*UnimplementedPlugin)(nil)
)
// OnEvent is a no-op default: it accepts the event without doing anything.
//
// Pointer receiver (like every other UnimplementedPlugin method): the type
// embeds a sync.RWMutex, and a value receiver would trip go vet's copylocks
// check even though this method never touches it.
func (*UnimplementedPlugin) OnEvent(context.Context, *Event) error {
return nil
}
// HandleWebhook is a no-op default: it returns 404, since an unhandled
// webhook path has nothing sensible to serve.
func (*UnimplementedPlugin) HandleWebhook(context.Context, *WebhookRequest) (*WebhookResponse, error) {
return &WebhookResponse{Status: 404}, nil
}
func (*UnimplementedPlugin) InvokeAgentTool(context.Context, *AgentToolRequest) (*AgentToolResult, error) {
return nil, status.Error(codes.Unimplemented, "agent tool invocation is not implemented")
}
// SetHost stores the Host injected by Serve. Call Host() from your
// overridden methods to reach kandev.
func (p *UnimplementedPlugin) SetHost(h Host) {
p.mu.Lock()
defer p.mu.Unlock()
p.host = h
}
// Host returns the Host injected by Serve, or nil if the broker connection
// hasn't completed yet (or Serve hasn't been called, e.g. in unit tests).
func (p *UnimplementedPlugin) Host() Host {
p.mu.RLock()
defer p.mu.RUnlock()
return p.host
}