MCO-707: Strip registry transport from os image URL for comparison

When comparing os image URLs in or to decide if reboot is needed,
sometimes the URL starts with a prefix (i.e docker:// or registry:), and sometimes
without.  In order to compare correctly, the prefix is removed before
comparison is done.

pkg/daemon/daemon.go

@@ -1071,7 +1071,7 @@ func (dn *Daemon) RunFirstbootCompleteMachineconfig() error {
 	// Start with an empty config, then add our *booted* osImageURL to
 	// it, reflecting the current machine state.
 	oldConfig := canonicalizeEmptyMC(nil)
-	oldConfig.Spec.OSImageURL = dn.bootedOSImageURL
+	oldConfig.Spec.OSImageURL = stripRegistryTransports(dn.bootedOSImageURL)
 
 	// Setting the Kernel Arguments is for comparison only with the desired MachineConfig.
 	// The resulting MC should not be for updating node configuration.
@@ -2295,6 +2295,25 @@ func (dn *Daemon) validateOnDiskStateWithImage(currentConfig *mcfgv1.MachineConf
 	return nil
 }
 
+// stripRegistryTransports removes the registry transport prefixes,
+// see https://docs.rs/ostree-ext/latest/ostree_ext/container/enum.Transport.html
+func stripRegistryTransports(url string) string {
+	registryTransports := []string{
+		"registry:",
+		"docker://",
+	}
+	for shouldUpdate := true; shouldUpdate; {
+		shouldUpdate = false
+		for _, rt := range registryTransports {
+			if strings.HasPrefix(url, rt) {
+				shouldUpdate = true
+				url = strings.Replace(url, rt, "", 1)
+			}
+		}
+	}
+	return url
+}
+
 // checkOS determines whether the booted system matches the target
 // osImageURL and if not whether we need to take action.  This function
 // returns `true` if no action is required, which is the case if we're
@@ -2320,7 +2339,7 @@ func (dn *Daemon) checkOS(osImageURL string) bool {
 		}
 	}
 
-	return dn.bootedOSImageURL == osImageURL
+	return stripRegistryTransports(dn.bootedOSImageURL) == osImageURL
 }
 
 // Close closes all the connections the node agent has open for it's lifetime

pkg/daemon/daemon_test.go

@@ -531,3 +531,17 @@ func TestPrepUpdateFromClusterOnDiskDrift(t *testing.T) {
 		})
 	}
 }
+
+func TestStripRegistryTransports(t *testing.T) {
+	expectedURL := "quay.io/example/foo@sha256:b5bb9d8014a0f9b1d61e21e796d78dccdf1352f23cd32812f4850b878ae4944c"
+	bootedURL := expectedURL
+	require.Equal(t, expectedURL, stripRegistryTransports(bootedURL))
+	bootedURL = "docker://" + expectedURL
+	require.Equal(t, expectedURL, stripRegistryTransports(bootedURL))
+	bootedURL = "registry:" + expectedURL
+	require.Equal(t, expectedURL, stripRegistryTransports(bootedURL))
+	bootedURL = "registry:docker://" + expectedURL
+	require.Equal(t, expectedURL, stripRegistryTransports(bootedURL))
+	bootedURL = "registryy:" + expectedURL
+	require.NotEqual(t, expectedURL, stripRegistryTransports(bootedURL))
+}