Method createTailnet

agent/agent.go:1723–1884

(
	ctx context.Context,
	agentID uuid.UUID,
	derpMap *tailcfg.DERPMap,
	derpForceWebSockets, disableDirectConnections bool,
	keySeed int64,
)

}

func (a *agent) createTailnet(
	ctx context.Context,
	agentID uuid.UUID,
	derpMap *tailcfg.DERPMap,
	derpForceWebSockets, disableDirectConnections bool,
	keySeed int64,
) (_ *tailnet.Conn, err error) {
	// Inject `CODER_AGENT_HEADER` into the DERP header.
	var header http.Header
	if client, ok := a.client.(*agentsdk.Client); ok {
		if headerTransport, ok := client.SDK.HTTPClient.Transport.(*codersdk.HeaderTransport); ok {
			header = headerTransport.Header
		}
	}
	network, err := tailnet.NewConn(&tailnet.Options{
		ID:                  agentID,
		Addresses:           a.wireguardAddresses(agentID),
		DERPMap:             derpMap,
		DERPForceWebSockets: derpForceWebSockets,
		DERPHeader:          &header,
		DERPTLSConfig:       a.derpTLSConfig,
		Logger:              a.logger.Named("net.tailnet"),
		ListenPort:          a.tailnetListenPort,
		BlockEndpoints:      disableDirectConnections,
	})
	if err != nil {
		return nil, xerrors.Errorf("create tailnet: %w", err)
	}
	defer func() {
		if err != nil {
			network.Close()
		}
	}()

	if err := a.sshServer.UpdateHostSigner(keySeed); err != nil {
		return nil, xerrors.Errorf("update host signer: %w", err)
	}

	for _, port := range []int{workspacesdk.AgentSSHPort, workspacesdk.AgentStandardSSHPort} {
		sshListener, err := network.Listen("tcp", ":"+strconv.Itoa(port))
		if err != nil {
			return nil, xerrors.Errorf("listen on the ssh port (%v): %w", port, err)
		}
		// nolint:revive // We do want to run the deferred functions when createTailnet returns.
		defer func() {
			if err != nil {
				_ = sshListener.Close()
			}
		}()
		if err = a.trackGoroutine(func() {
			_ = a.sshServer.Serve(sshListener)
		}); err != nil {
			return nil, err
		}
	}

	reconnectingPTYListener, err := network.Listen("tcp", ":"+strconv.Itoa(workspacesdk.AgentReconnectingPTYPort))
	if err != nil {