p2p,rpc: add rpc to query seed nodes from db (fractalplatform#496)

* p2p,rpc: add rpc to query seed nodes from db

ftservice/apibackend.go

@@ -336,6 +336,16 @@ func (b *APIBackend) RemoveTrustedPeer(url string) error {
 	return err
 }
 
+// SeedNodes returns all seed nodes.
+func (b *APIBackend) SeedNodes() []string {
+	nodes := b.ftservice.p2pServer.SeedNodes()
+	ns := make([]string, len(nodes))
+	for i, node := range nodes {
+		ns[i] = node.String()
+	}
+	return ns
+}
+
 // PeerCount returns the number of connected peers.
 func (b *APIBackend) PeerCount() int {
 	return b.ftservice.p2pServer.PeerCount()

p2p/dial.go

@@ -89,6 +89,7 @@ type discoverTable interface {
 	Resolve(*enode.Node) *enode.Node
 	LookupRandom() []*enode.Node
 	ReadRandomNodes([]*enode.Node) int
+	SeedNodes() []*enode.Node
 }
 
 // the dial history remembers recent dials.

p2p/dial_test.go

@@ -85,6 +85,7 @@ func (t fakeTable) Close()                                {}
 func (t fakeTable) LookupRandom() []*enode.Node           { return nil }
 func (t fakeTable) Resolve(*enode.Node) *enode.Node       { return nil }
 func (t fakeTable) ReadRandomNodes(buf []*enode.Node) int { return copy(buf, t) }
+func (t fakeTable) SeedNodes() []*enode.Node              { return nil }
 
 // This test checks that dynamic dials are launched from discovery results.
 func TestDialStateDynDial(t *testing.T) {
@@ -703,3 +704,4 @@ func (t *resolveMock) Self() *enode.Node                     { return new(enode.
 func (t *resolveMock) Close()                                {}
 func (t *resolveMock) LookupRandom() []*enode.Node           { return nil }
 func (t *resolveMock) ReadRandomNodes(buf []*enode.Node) int { return 0 }
+func (t *resolveMock) SeedNodes() []*enode.Node              { return nil }

p2p/discover/table.go

@@ -141,6 +141,11 @@ func (tab *Table) Self() *enode.Node {
 	return unwrapNode(tab.self)
 }
 
+// SeedNodes return all of the seed nodes
+func (tab *Table) SeedNodes() []*enode.Node {
+	return tab.db.QueryAllSeeds()
+}
+
 // ReadRandomNodes fills the given slice with random nodes from the table. The results
 // are guaranteed to be unique for a single invocation, no node will appear twice.
 func (tab *Table) ReadRandomNodes(buf []*enode.Node) (n int) {

p2p/enode/nodedb.go

@@ -329,6 +329,30 @@ seek:
 	return nodes
 }
 
+// QueryAllSeeds retrieves all nodes to be used as potential seed nodes
+// for bootstrapping.
+func (db *DB) QueryAllSeeds() []*Node {
+	var (
+		nodes []*Node
+		it    = db.lvl.NewIterator(nil, nil)
+	)
+	defer it.Release()
+seek:
+	for it.Next() {
+		n := nextNode(it)
+		if n == nil {
+			break
+		}
+		for i := range nodes {
+			if nodes[i].ID() == n.ID() {
+				continue seek
+			}
+		}
+		nodes = append(nodes, n)
+	}
+	return nodes
+}
+
 // reads the next node record from the iterator, skipping over other
 // database entries.
 func nextNode(it iterator.Iterator) *Node {

p2p/server.go

@@ -302,6 +302,10 @@ func (srv *Server) Peers() []*Peer {
 	return ps
 }
 
+func (srv *Server) SeedNodes() []*enode.Node {
+	return srv.ntab.SeedNodes()
+}
+
 // PeerCount returns the number of connected peers.
 func (srv *Server) PeerCount() int {
 	var count int

rpcapi/backend.go

@@ -81,6 +81,7 @@ type Backend interface {
 	RemovePeer(url string) error
 	AddTrustedPeer(url string) error
 	RemoveTrustedPeer(url string) error
+	SeedNodes() []string
 	PeerCount() int
 	Peers() []string
 	BadNodesCount() int

rpcapi/p2p.go

@@ -111,6 +111,11 @@ func (api *PrivateP2pAPI) RemoveTrustedPeer(url string) (bool, error) {
 	return true, nil
 }
 
+// SeedNodes returns all seed nodes.
+func (api *PrivateP2pAPI) SeedNodes() []string {
+	return api.b.SeedNodes()
+}
+
 // PeerCount return number of connected peers
 func (api *PrivateP2pAPI) PeerCount() int {
 	return api.b.PeerCount()