Add dynamic-config-server-provisioning flag

3 files changed, 17 insertions, 3 deletions

diff --git a/flags/src/main/java/com/yahoo/vespa/flags/Flags.java b/flags/src/main/java/com/yahoo/vespa/flags/Flags.java
index 0b9b9e418bc..f67bcb22e63 100644
--- a/flags/src/main/java/com/yahoo/vespa/flags/Flags.java
+++ b/flags/src/main/java/com/yahoo/vespa/flags/Flags.java
@@ -279,6 +279,12 @@ public class Flags {
             "Takes effect at redeployment",
             ZONE_ID, APPLICATION_ID);
 
+    public static final UnboundBooleanFlag DYNAMIC_CONFIG_SERVER_PROVISIONING = defineFeatureFlag(
+            "dynamic-config-server-provisioning", false,
+            List.of("mpolden", "hakon"), "2021-03-03", "2021-05-01",
+            "Enable dynamic provisioning of config servers",
+            "Takes effect immediately, for subsequent provisioning");
+
     /** WARNING: public for testing: All flags should be defined in {@link Flags}. */
     public static UnboundBooleanFlag defineFeatureFlag(String flagId, boolean defaultValue, List<String> owners,
                                                        String createdAt, String expiresAt, String description,
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/GroupPreparer.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/GroupPreparer.java
index e6473e62922..780b080e3c9 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/GroupPreparer.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/GroupPreparer.java
@@ -7,6 +7,7 @@ import com.yahoo.config.provision.ClusterSpec;
 import com.yahoo.config.provision.NodeType;
 import com.yahoo.config.provision.OutOfCapacityException;
 import com.yahoo.transaction.Mutex;
+import com.yahoo.vespa.flags.BooleanFlag;
 import com.yahoo.vespa.flags.FetchVector;
 import com.yahoo.vespa.flags.FlagSource;
 import com.yahoo.vespa.flags.Flags;
@@ -34,6 +35,7 @@ public class GroupPreparer {
     private final NodeRepository nodeRepository;
     private final Optional<HostProvisioner> hostProvisioner;
     private final StringFlag allocateOsRequirementFlag;
+    private final BooleanFlag provisionConfigServerDynamically;
 
     public GroupPreparer(NodeRepository nodeRepository,
                          Optional<HostProvisioner> hostProvisioner,
@@ -41,6 +43,7 @@ public class GroupPreparer {
         this.nodeRepository = nodeRepository;
         this.hostProvisioner = hostProvisioner;
         this.allocateOsRequirementFlag = Flags.ALLOCATE_OS_REQUIREMENT.bindTo(flagSource);
+        this.provisionConfigServerDynamically = Flags.DYNAMIC_CONFIG_SERVER_PROVISIONING.bindTo(flagSource);
     }
 
     /**
@@ -87,9 +90,11 @@ public class GroupPreparer {
             NodeAllocation allocation = prepareAllocation(application, cluster, requestedNodes, surplusActiveNodes,
                                                           indices::next, wantedGroups, allocationLock,
                                                           allocateOsRequirement);
-
-            if (nodeRepository.zone().getCloud().dynamicProvisioning()) {
-                NodeType hostType = allocation.nodeType().hostType();
+            NodeType hostType = allocation.nodeType().hostType();
+            boolean hostTypeSupportsDynamicProvisioning = hostType == NodeType.host ||
+                                                      (hostType == NodeType.confighost &&
+                                                       provisionConfigServerDynamically.value());
+            if (nodeRepository.zone().getCloud().dynamicProvisioning() && hostTypeSupportsDynamicProvisioning) {
                 final Version osVersion;
                 if (allocateOsRequirement.equals("rhel8")) {
                     osVersion = new Version(8, Integer.MAX_VALUE /* always use latest 8 version */, 0);
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/DynamicProvisioningMaintainerTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/DynamicProvisioningMaintainerTest.java
index dea7e50d641..6e979de2879 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/DynamicProvisioningMaintainerTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/DynamicProvisioningMaintainerTest.java
@@ -16,6 +16,7 @@ import com.yahoo.config.provision.ParentHostUnavailableException;
 import com.yahoo.config.provision.RegionName;
 import com.yahoo.config.provision.SystemName;
 import com.yahoo.config.provision.Zone;
+import com.yahoo.vespa.flags.Flags;
 import com.yahoo.vespa.flags.InMemoryFlagSource;
 import com.yahoo.vespa.flags.PermanentFlags;
 import com.yahoo.vespa.flags.custom.ClusterCapacity;
@@ -425,6 +426,7 @@ public class DynamicProvisioningMaintainerTest {
         DynamicProvisioningTester dynamicProvisioningTester = new DynamicProvisioningTester(cloud, new MockNameResolver().mockAnyLookup());
         ProvisioningTester tester = dynamicProvisioningTester.provisioningTester;
         dynamicProvisioningTester.hostProvisioner.overrideHostFlavor("default");
+        dynamicProvisioningTester.flagSource.withBooleanFlag(Flags.DYNAMIC_CONFIG_SERVER_PROVISIONING.id(), true);
 
         // Initial config server hosts are provisioned manually
         ApplicationId hostApp = ApplicationId.from("hosted-vespa", "configserver-host", "default");
@@ -555,6 +557,7 @@ public class DynamicProvisioningMaintainerTest {
                                                                                      RegionName.defaultName()))
                                                                       .flavors(flavors.getFlavors())
                                                                       .nameResolver(nameResolver)
+                                                                      .flagSource(flagSource)
                                                                       .hostProvisioner(hostProvisioner)
                                                                       .build();
             this.nodeRepository = provisioningTester.nodeRepository();