pkg/api/api0: Store launcher version in server list

3 files changed, 24 insertions, 1 deletions

diff --git a/pkg/api/api0/api.go b/pkg/api/api0/api.go
index 10729e1..51d3c18 100644
--- a/pkg/api/api0/api.go
+++ b/pkg/api/api0/api.go
@@ -148,6 +148,25 @@ func (h *Handler) checkLauncherVersion(r *http.Request) bool {
 	return semver.Compare(rver, mver) >= 0
 }
 
+// extractLauncherVersion extracts the launcher version from r, returning an
+// empty string if it's missing or invalid.
+func (h *Handler) extractLauncherVersion(r *http.Request) string {
+	rver, _, _ := strings.Cut(r.Header.Get("User-Agent"), " ")
+	if x := strings.TrimPrefix(rver, "R2Northstar/"); rver != x {
+		if len(x) > 0 && x[0] != 'v' {
+			rver = "v" + x
+		} else {
+			rver = x
+		}
+	} else {
+		rver = ""
+	}
+	if rver != "" && semver.IsValid(rver) {
+		return rver[1:]
+	}
+	return ""
+}
+
 // respFail writes a {success:false,error:ErrorObj} response with the provided
 // response status.
 func respFail(w http.ResponseWriter, r *http.Request, status int, obj ErrorObj) {
diff --git a/pkg/api/api0/server.go b/pkg/api/api0/server.go
index 756c48b..68c94c9 100644
--- a/pkg/api/api0/server.go
+++ b/pkg/api/api0/server.go
@@ -85,7 +85,9 @@ func (h *Handler) handleServerUpsert(w http.ResponseWriter, r *http.Request) {
 
 	var s *Server
 	if canCreate {
-		s = &Server{}
+		s = &Server{
+			LauncherVersion: h.extractLauncherVersion(r),
+		}
 	}
 
 	var u *ServerUpdate
diff --git a/pkg/api/api0/serverlist.go b/pkg/api/api0/serverlist.go
index 04ee79b..35be9f6 100644
--- a/pkg/api/api0/serverlist.go
+++ b/pkg/api/api0/serverlist.go
@@ -53,6 +53,8 @@ type Server struct {
 	Addr     netip.AddrPort // unique, must not be modified after creation
 	AuthPort uint16         // unique with Addr.Addr(), must not be modified after creation
 
+	LauncherVersion string // for metrics
+
 	Name        string
 	Description string
 	Password    string // blank for none