Restore Graceful Restarting & Socket Activation (#7274)

* Prevent deadlock in indexer initialisation during graceful restart

* Move from gracehttp to our own service to add graceful ssh

* Add timeout for start of indexers and make hammer time configurable

* Fix issue with re-initialization in indexer during tests

* move the code to detect use of closed to graceful

* Handle logs gracefully - add a pid suffix just before restart

* Move to using a cond and a holder for indexers

* use time.Since

* Add some comments and attribution

* update modules.txt

* Use zero to disable timeout

* Move RestartProcess to its own file

* Add cleanup routine

cmd/web_windows.go

@@ -7,6 +7,7 @@
 package cmd
 
 import (
+	"crypto/tls"
 	"net/http"
 )
 
@@ -17,3 +18,20 @@ func runHTTP(listenAddr string, m http.Handler) error {
 func runHTTPS(listenAddr, certFile, keyFile string, m http.Handler) error {
 	return http.ListenAndServeTLS(listenAddr, certFile, keyFile, m)
 }
+
+func runHTTPSWithTLSConfig(listenAddr string, tlsConfig *tls.Config, m http.Handler) error {
+	server := &http.Server{
+		Addr:      listenAddr,
+		Handler:   m,
+		TLSConfig: tlsConfig,
+	}
+	return server.ListenAndServeTLS("", "")
+}
+
+// NoHTTPRedirector is a no-op on Windows
+func NoHTTPRedirector() {
+}
+
+// NoMainListener is a no-op on Windows
+func NoMainListener() {
+}