Allow no adminserver element in services.xml

Create single config server on container node if not given

3 files changed, 21 insertions, 5 deletions

diff --git a/config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/DomAdminV2Builder.java b/config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/DomAdminV2Builder.java
index e081848d01c..ac5633a1461 100644
--- a/config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/DomAdminV2Builder.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/DomAdminV2Builder.java
@@ -17,7 +17,6 @@ import com.yahoo.vespa.model.admin.clustercontroller.ClusterControllerContainerC
 import com.yahoo.vespa.model.builder.xml.dom.VespaDomBuilder.DomConfigProducerBuilder;
 import com.yahoo.vespa.model.container.Container;
 import org.w3c.dom.Element;
-
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
@@ -69,7 +68,8 @@ public class DomAdminV2Builder extends DomAdminBuilderBase {
     private Logserver parseLogserver(DeployState deployState, Admin admin, Element adminE) {
         Element logserverE = XML.getChild(adminE, "logserver");
         if (logserverE == null) {
-            logserverE = XML.getChild(adminE, "adminserver");
+            var adminserverE = XML.getChild(adminE, "adminserver");
+            logserverE = adminserverE != null ? adminserverE : adminE;
         }
         return new LogserverBuilder().build(deployState, admin, logserverE);
     }
@@ -104,13 +104,18 @@ public class DomAdminV2Builder extends DomAdminBuilderBase {
     }
 
     private List<Configserver> getConfigServers(DeployState deployState, AbstractConfigProducer<?> parent, Element adminE) {
-        SimpleConfigProducer<?> configServers = new SimpleConfigProducer<>(parent, "configservers");
         Element configserversE = XML.getChild(adminE, "configservers");
         if (configserversE == null) {
             Element adminserver = XML.getChild(adminE, "adminserver");
-            return List.of(new ConfigserverBuilder(0, configServerSpecs).build(deployState, configServers, adminserver));
+            if (adminserver == null) {
+                return createSingleConfigServer(deployState, parent);
+            } else {
+                SimpleConfigProducer<?> configServers = new SimpleConfigProducer<>(parent, "configservers");
+                return List.of(new ConfigserverBuilder(0, configServerSpecs).build(deployState, configServers, adminserver));
+            }
         }
         else {
+            SimpleConfigProducer<?> configServers = new SimpleConfigProducer<>(parent, "configservers");
             List<Configserver> configservers = new ArrayList<>();
             int i = 0;
             for (Element configserverE : XML.getChildren(configserversE, "configserver"))
diff --git a/config-model/src/main/resources/schema/admin.rnc b/config-model/src/main/resources/schema/admin.rnc
index 4e916e0901f..6f4c90159d8 100644
--- a/config-model/src/main/resources/schema/admin.rnc
+++ b/config-model/src/main/resources/schema/admin.rnc
@@ -4,7 +4,7 @@ Admin = AdminV2 | AdminV3 | AdminV4
 AdminV2 =
  element admin {
    attribute version { "2.0" } &
-   element adminserver { service.attlist } &
+   element adminserver { service.attlist }? &
    GenericConfig* &
    LogServer? &
    ConfigServers? &
diff --git a/config-model/src/test/java/com/yahoo/vespa/model/builder/xml/dom/DomAdminV2BuilderTest.java b/config-model/src/test/java/com/yahoo/vespa/model/builder/xml/dom/DomAdminV2BuilderTest.java
index 8a2a23a795d..a38f0ebe476 100755
--- a/config-model/src/test/java/com/yahoo/vespa/model/builder/xml/dom/DomAdminV2BuilderTest.java
+++ b/config-model/src/test/java/com/yahoo/vespa/model/builder/xml/dom/DomAdminV2BuilderTest.java
@@ -101,6 +101,11 @@ public class DomAdminV2BuilderTest extends DomBuilderTest {
                         "</admin>").getDocumentElement();
     }
 
+    private Element servicesAdminNoAdminServerOrConfigServer() {
+        return XML.getDocument("<admin version=\"2.0\">" +
+                        "</admin>").getDocumentElement();
+    }
+
     @Test
     void multitenant() {
         List<ConfigServerSpec> configServerSpecs = Arrays.asList(
@@ -182,6 +187,12 @@ public class DomAdminV2BuilderTest extends DomBuilderTest {
         assertEquals("foobar", config.logserver().host());
     }
 
+    @Test
+    void noAdminServerOrConfigServer() {
+        Admin admin = buildAdmin(servicesAdminNoAdminServerOrConfigServer());
+        assertEquals(1, admin.getConfigservers().size());
+    }
+
     private Admin buildAdmin(Element xml) {
         return buildAdmin(xml, false, new ArrayList<>());
     }