cloud/shepherd/equinix: implement recoverer

This implements basic recovery functionality for 'stuck' agents. The
shepherd will notice machines with a agent that either never sent a
heartbeat, or stopped sending heartbeats, and will remove their agent
started tags and reboot the machine. Then, the main agent start logic
should kick in again.

More complex recovery flows can be implemented later, this will do for
now.

Change-Id: I2c1b0d0465e4e302cdecce950a041581c2dc8548
Reviewed-on: https://review.monogon.dev/c/monogon/+/1560
Tested-by: Jenkins CI
Reviewed-by: Tim Windelschmidt <tim@monogon.tech>
diff --git a/cloud/shepherd/equinix/manager/server/main.go b/cloud/shepherd/equinix/manager/server/main.go
index e9b9289..2a293dc 100644
--- a/cloud/shepherd/equinix/manager/server/main.go
+++ b/cloud/shepherd/equinix/manager/server/main.go
@@ -24,6 +24,7 @@
 	SharedConfig      manager.SharedConfig
 	ProvisionerConfig manager.ProvisionerConfig
 	InitializerConfig manager.InitializerConfig
+	RecovererConfig   manager.RecovererConfig
 	WebugConfig       webug.Config
 	API               wrapngo.Opts
 }
@@ -46,6 +47,7 @@
 	c.SharedConfig.RegisterFlags("")
 	c.ProvisionerConfig.RegisterFlags()
 	c.InitializerConfig.RegisterFlags()
+	c.RecovererConfig.RegisterFlags()
 	c.WebugConfig.RegisterFlags()
 	c.API.RegisterFlags()
 }
@@ -87,6 +89,11 @@
 		klog.Exitf("%v", err)
 	}
 
+	recoverer, err := manager.NewRecoverer(api, c.RecovererConfig)
+	if err != nil {
+		klog.Exitf("%v", err)
+	}
+
 	conn, err := c.BMDB.Open(true)
 	if err != nil {
 		klog.Exitf("Failed to open BMDB connection: %v", err)
@@ -105,6 +112,12 @@
 		}
 	}()
 	go func() {
+		err = manager.RunControlLoop(ctx, conn, recoverer)
+		if err != nil {
+			klog.Exit(err)
+		}
+	}()
+	go func() {
 		if err := c.WebugConfig.Start(ctx, conn); err != nil && err != ctx.Err() {
 			klog.Exitf("Failed to start webug: %v", err)
 		}