@@ -1186,9 +1186,9 @@ func (a *agent) createOrUpdateNetwork(manifestOK, networkOK *checkpoint) func(co
11861186network := a .network
11871187a .closeMutex .Unlock ()
11881188if network == nil {
1189- keySeed ,err := WorkspaceKeySeed (manifest .WorkspaceID ,manifest .AgentName )
1189+ keySeed ,err := SSHKeySeed (manifest .OwnerName , manifest . WorkspaceName ,manifest .AgentName )
11901190if err != nil {
1191- return xerrors .Errorf ("generateseed from workspace id : %w" ,err )
1191+ return xerrors .Errorf ("generateSSH key seed : %w" ,err )
11921192}
11931193// use the graceful context here, because creating the tailnet is not itself tied to the
11941194// agent API.
@@ -1518,14 +1518,11 @@ func (a *agent) runCoordinator(ctx context.Context, tClient tailnetproto.DRPCTai
15181518a .logger .Info (ctx ,"connected to coordination RPC" )
15191519
15201520// This allows the Close() routine to wait for the coordinator to gracefully disconnect.
1521- a . closeMutex . Lock ()
1522- if a . isClosed () {
1523- return nil
1521+ disconnected := a . setCoordDisconnected ()
1522+ if disconnected == nil {
1523+ return nil // already closed by something else
15241524}
1525- disconnected := make (chan struct {})
1526- a .coordDisconnected = disconnected
15271525defer close (disconnected )
1528- a .closeMutex .Unlock ()
15291526
15301527ctrl := tailnet .NewAgentCoordinationController (a .logger ,network )
15311528coordination := ctrl .New (coordinate )
@@ -1547,6 +1544,17 @@ func (a *agent) runCoordinator(ctx context.Context, tClient tailnetproto.DRPCTai
15471544return <- errCh
15481545}
15491546
1547+ func (a * agent )setCoordDisconnected ()chan struct {} {
1548+ a .closeMutex .Lock ()
1549+ defer a .closeMutex .Unlock ()
1550+ if a .isClosed () {
1551+ return nil
1552+ }
1553+ disconnected := make (chan struct {})
1554+ a .coordDisconnected = disconnected
1555+ return disconnected
1556+ }
1557+
15501558// runDERPMapSubscriber runs a coordinator and returns if a reconnect should occur.
15511559func (a * agent )runDERPMapSubscriber (ctx context.Context ,tClient tailnetproto.DRPCTailnetClient24 ,network * tailnet.Conn )error {
15521560defer a .logger .Debug (ctx ,"disconnected from derp map RPC" )
@@ -2068,12 +2076,31 @@ func PrometheusMetricsHandler(prometheusRegistry *prometheus.Registry, logger sl
20682076})
20692077}
20702078
2071- //WorkspaceKeySeed convertsa WorkspaceID UUID andagent name to an int64 hash.
2079+ //SSHKeySeed convertsan owner userName, workspaceName andagentName to an int64 hash.
20722080// This uses the FNV-1a hash algorithm which provides decent distribution and collision
20732081// resistance for string inputs.
2074- func WorkspaceKeySeed (workspaceID uuid.UUID ,agentName string ) (int64 ,error ) {
2082+ //
2083+ // Why owner username, workspace name, and agent name? These are the components that are used in hostnames for the
2084+ // workspace over SSH, and so we want the workspace to have a stable key with respect to these. We don't use the
2085+ // respective UUIDs. The workspace UUID would be different if you delete and recreate a workspace with the same name.
2086+ // The agent UUID is regenerated on each build. Since Coder's Tailnet networking is handling the authentication, we
2087+ // should not be showing users warnings about host SSH keys.
2088+ func SSHKeySeed (userName ,workspaceName ,agentName string ) (int64 ,error ) {
20752089h := fnv .New64a ()
2076- _ ,err := h .Write (workspaceID [:])
2090+ _ ,err := h .Write ([]byte (userName ))
2091+ if err != nil {
2092+ return 42 ,err
2093+ }
2094+ // null separators between strings so that (dog, foodstuff) is distinct from (dogfood, stuff)
2095+ _ ,err = h .Write ([]byte {0 })
2096+ if err != nil {
2097+ return 42 ,err
2098+ }
2099+ _ ,err = h .Write ([]byte (workspaceName ))
2100+ if err != nil {
2101+ return 42 ,err
2102+ }
2103+ _ ,err = h .Write ([]byte {0 })
20772104if err != nil {
20782105return 42 ,err
20792106}