In geth code files, where is the implementation of generating a fixed enode id?

Question

The process of generating an enode id seems to be: "Generate private key -> Generate public key -> add the IP and port". If I restart the computer, the node id changes as well. How can I do if I want to fixed this node id (like the bootnode key), where is the implementation of this process?

Answer 1

I suggest to look at node/node.go

// Start create a live P2P node and starts running it.
func (n *Node) Start() error {
    n.lock.Lock()
    defer n.lock.Unlock()

    // Short circuit if the node's already running
    if n.server != nil {
        return ErrNodeRunning
    }
    if err := n.openDataDir(); err != nil {
        return err
    }

    // Initialize the p2p server. This creates the node key and
    // discovery databases.
    n.serverConfig = n.config.P2P
    n.serverConfig.PrivateKey = n.config.NodeKey()
    n.serverConfig.Name = n.config.NodeName()
    n.serverConfig.Logger = n.log
    if n.serverConfig.StaticNodes == nil {
        n.serverConfig.StaticNodes = n.config.StaticNodes()
    }
    if n.serverConfig.TrustedNodes == nil {
        n.serverConfig.TrustedNodes = n.config.TrustedNodes()
    }
    if n.serverConfig.NodeDatabase == "" {
        n.serverConfig.NodeDatabase = n.config.NodeDB()
    }
    running := &p2p.Server{Config: n.serverConfig}
    n.log.Info("Starting peer-to-peer node", "instance", n.serverConfig.Name)

There is also cmd/bootnode/main.go :

case *genKey != "":
    nodeKey, err = crypto.GenerateKey()
    if err != nil {
        utils.Fatalf("could not generate key: %v", err)
    }
    if err = crypto.SaveECDSA(*genKey, nodeKey); err != nil {
        utils.Fatalf("%v", err)
    }
    return