plugin: add plugin type for daemon plugins

This allows users to run multiple go-ipfs "clients" in-process.

License: MIT
Signed-off-by: Steven Allen <steven@stebalien.com>

cmd/ipfs/daemon.go

@@ -17,6 +17,7 @@ import (
 	oldcmds "github.com/ipfs/go-ipfs/commands"
 	"github.com/ipfs/go-ipfs/core"
 	commands "github.com/ipfs/go-ipfs/core/commands"
+	coreapi "github.com/ipfs/go-ipfs/core/coreapi"
 	corehttp "github.com/ipfs/go-ipfs/core/corehttp"
 	corerepo "github.com/ipfs/go-ipfs/core/corerepo"
 	nodeMount "github.com/ipfs/go-ipfs/fuse/node"
@@ -25,6 +26,7 @@ import (
 
 	ma "gx/ipfs/QmNTCey11oxhb1AxDnQBRHtdhap6Ctud872NjAYPYYXPuc/go-multiaddr"
 	cmds "gx/ipfs/QmR77mMvvh8mJBBWQmBfQBu8oD38NUN4KE9SL2gDgAQNc6/go-ipfs-cmds"
+	goprocess "gx/ipfs/QmSF8fPo3jgVBAy8fpdjjYqgG87dkJgUprRBHRd2tmfgpP/goprocess"
 	"gx/ipfs/QmTQuFQWHAWy4wMH6ZyPfGiawA5u9T8rs79FENoV8yXaoS/client_golang/prometheus"
 	mprome "gx/ipfs/QmVMcMs6duiwLzvhF6xWM3yc4GgjpNoctKFhvtBch5tpgo/go-metrics-prometheus"
 	"gx/ipfs/QmZcLBXKaFe8ND5YHPkJRAwmhJGrVsi1JqDZNyJ4nRK5Mj/go-multiaddr-net"
@@ -355,6 +357,18 @@ func daemonFunc(req *cmds.Request, re cmds.ResponseEmitter, env cmds.Environment
 		return node, nil
 	}
 
+	// Start "core" plugins. We want to do this *before* starting the HTTP
+	// API as the user may be relying on these plugins.
+	api, err := coreapi.NewCoreAPI(node)
+	if err != nil {
+		return err
+	}
+	err = cctx.Plugins.Start(api)
+	if err != nil {
+		return err
+	}
+	node.Process().AddChild(goprocess.WithTeardown(cctx.Plugins.Close))
+
 	// construct api endpoint - every time
 	apiErrc, err := serveHTTPApi(req, cctx)
 	if err != nil {
@@ -391,6 +405,7 @@ func daemonFunc(req *cmds.Request, re cmds.ResponseEmitter, env cmds.Environment
 	// initialize metrics collector
 	prometheus.MustRegister(&corehttp.IpfsNodeCollector{Node: node})
 
+	// The daemon is *finally* ready.
 	fmt.Printf("Daemon is ready\n")
 
 	// Give the user some immediate feedback when they hit C-c

plugin/daemon.go

@@ -0,0 +1,14 @@
+package plugin
+
+import (
+	coreiface "github.com/ipfs/go-ipfs/core/coreapi/interface"
+)
+
+// PluginDaemon is an interface for daemon plugins. These plugins will be run on
+// the daemon and will be given access to an implementation of the CoreAPI.
+type PluginDaemon interface {
+	Plugin
+
+	Start(coreiface.CoreAPI) error
+	Close() error
+}

plugin/loader/loader.go

@@ -2,10 +2,13 @@ package loader
 
 import (
 	"fmt"
-	"github.com/ipfs/go-ipfs/core/coredag"
-	"github.com/ipfs/go-ipfs/plugin"
-	"github.com/ipfs/go-ipfs/repo/fsrepo"
 	"os"
+	"strings"
+
+	coreiface "github.com/ipfs/go-ipfs/core/coreapi/interface"
+	coredag "github.com/ipfs/go-ipfs/core/coredag"
+	plugin "github.com/ipfs/go-ipfs/plugin"
+	fsrepo "github.com/ipfs/go-ipfs/repo/fsrepo"
 
 	ipld "gx/ipfs/QmRL22E4paat7ky7vx9MLpR97JHHbFPrg3ytFQw6qp1y1s/go-ipld-format"
 	opentracing "gx/ipfs/QmWLWmRVSiagqP15jczsGME1qpob6HDbtbHAY2he9W5iUo/opentracing-go"
@@ -106,6 +109,45 @@ func (loader *PluginLoader) Inject() error {
 	return nil
 }
 
+// Start starts all long-running plugins.
+func (loader *PluginLoader) Start(iface coreiface.CoreAPI) error {
+	for i, pl := range loader.plugins {
+		if pl, ok := pl.(plugin.PluginDaemon); ok {
+			err := pl.Start(iface)
+			if err != nil {
+				closePlugins(loader.plugins[i:])
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// StopDaemon stops all long-running plugins.
+func (loader *PluginLoader) Close() error {
+	return closePlugins(loader.plugins)
+}
+
+func closePlugins(plugins []plugin.Plugin) error {
+	var errs []string
+	for _, pl := range plugins {
+		if pl, ok := pl.(plugin.PluginDaemon); ok {
+			err := pl.Close()
+			if err != nil {
+				errs = append(errs, fmt.Sprintf(
+					"error closing plugin %s: %s",
+					pl.Name(),
+					err.Error(),
+				))
+			}
+		}
+	}
+	if errs != nil {
+		return fmt.Errorf(strings.Join(errs, "\n"))
+	}
+	return nil
+}
+
 func injectDatastorePlugin(pl plugin.PluginDatastore) error {
 	return fsrepo.AddDatastoreConfigHandler(pl.DatastoreTypeName(), pl.DatastoreConfigParser())
 }