Merge pull request #2854 from hashicorp/b-2827-agent-services

Never remove unknown agent services

command/agent/consul/client.go

@@ -779,7 +779,9 @@ func createCheckReg(serviceID, checkID string, check *structs.ServiceCheck, host
 }
 
 // isNomadService returns true if the ID matches the pattern of a Nomad managed
-// service.
+// service. Agent services return false as independent client and server agents
+// may be running on the same machine. #2827
 func isNomadService(id string) bool {
-	return strings.HasPrefix(id, nomadServicePrefix)
+	const prefix = nomadServicePrefix + "-executor"
+	return strings.HasPrefix(id, prefix)
 }

command/agent/consul/unit_test.go

@@ -1231,3 +1231,27 @@ func TestConsul_DriverNetwork_Change(t *testing.T) {
 
 	syncAndAssertPort(net.PortMap["x"])
 }
+
+// TestIsNomadService asserts the isNomadService helper returns true for Nomad
+// task IDs and false for unknown IDs and Nomad agent IDs (see #2827).
+func TestIsNomadService(t *testing.T) {
+	tests := []struct {
+		id     string
+		result bool
+	}{
+		{"_nomad-client-nomad-client-http", false},
+		{"_nomad-server-nomad-serf", false},
+		{"_nomad-executor-abc", true},
+		{"_nomad-executor", true},
+		{"not-nomad", false},
+	}
+
+	for _, test := range tests {
+		t.Run(test.id, func(t *testing.T) {
+			actual := isNomadService(test.id)
+			if actual != test.result {
+				t.Error("%q should be %t but found %t", test.id, test.result, actual)
+			}
+		})
+	}
+}