Prototype with single host server and no admin panel (#2)

Reviewed-on: wrenn/sandbox#2
Co-authored-by: pptx704 <rafeed@omukk.dev>
Co-committed-by: pptx704 <rafeed@omukk.dev>

envd/internal/permissions/keepalive.go

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: Apache-2.0
+
+package permissions
+
+import (
+	"strconv"
+	"time"
+
+	"connectrpc.com/connect"
+)
+
+const defaultKeepAliveInterval = 90 * time.Second
+
+func GetKeepAliveTicker[T any](req *connect.Request[T]) (*time.Ticker, func()) {
+	keepAliveIntervalHeader := req.Header().Get("Keepalive-Ping-Interval")
+
+	var interval time.Duration
+
+	keepAliveIntervalInt, err := strconv.Atoi(keepAliveIntervalHeader)
+	if err != nil {
+		interval = defaultKeepAliveInterval
+	} else {
+		interval = time.Duration(keepAliveIntervalInt) * time.Second
+	}
+
+	ticker := time.NewTicker(interval)
+
+	return ticker, func() {
+		ticker.Reset(interval)
+	}
+}