Basic support for explicit instance

4 files changed, 231 insertions, 161 deletions

diff --git a/config-model-api/src/main/java/com/yahoo/config/application/api/DeploymentInstancesSpec.java b/config-model-api/src/main/java/com/yahoo/config/application/api/DeploymentInstancesSpec.java
index 13e7ba91049..344f3438804 100644
--- a/config-model-api/src/main/java/com/yahoo/config/application/api/DeploymentInstancesSpec.java
+++ b/config-model-api/src/main/java/com/yahoo/config/application/api/DeploymentInstancesSpec.java
@@ -25,7 +25,7 @@ import java.util.stream.Collectors;
 public class DeploymentInstancesSpec extends DeploymentSpec.Step {
 
     /** The instances deployed in this step */
-    private final List<InstanceName> names;
+    private final List<InstanceName> ids;
 
     private final List<DeploymentSpec.Step> steps;
     private final DeploymentSpec.UpgradePolicy upgradePolicy;
@@ -33,30 +33,33 @@ public class DeploymentInstancesSpec extends DeploymentSpec.Step {
     private final Optional<String> globalServiceId;
     private final Optional<AthenzDomain> athenzDomain;
     private final Optional<AthenzService> athenzService;
+    private final Notifications notifications;
     private final List<Endpoint> endpoints;
 
-    public DeploymentInstancesSpec(List<InstanceName> names,
+    public DeploymentInstancesSpec(List<InstanceName> ids,
                                    List<DeploymentSpec.Step> steps,
                                    DeploymentSpec.UpgradePolicy upgradePolicy,
                                    List<DeploymentSpec.ChangeBlocker> changeBlockers,
                                    Optional<String> globalServiceId,
                                    Optional<AthenzDomain> athenzDomain,
                                    Optional<AthenzService> athenzService,
+                                   Notifications notifications,
                                    List<Endpoint> endpoints) {
-        this.names = List.copyOf(names);
+        this.ids = List.copyOf(ids);
         this.steps = List.copyOf(completeSteps(new ArrayList<>(steps)));
         this.upgradePolicy = upgradePolicy;
         this.changeBlockers = changeBlockers;
         this.globalServiceId = globalServiceId;
         this.athenzDomain = athenzDomain;
         this.athenzService = athenzService;
+        this.notifications = notifications;
         this.endpoints = List.copyOf(validateEndpoints(endpoints, this.steps));
         validateZones(this.steps);
         validateEndpoints(this.steps, globalServiceId, this.endpoints);
         validateAthenz();
     }
 
-    public List<InstanceName> names() { return names; }
+    public List<InstanceName> names() { return ids; }
 
     /** Adds missing required steps and reorders steps to a permissible order */
     private static List<DeploymentSpec.Step> completeSteps(List<DeploymentSpec.Step> steps) {
@@ -222,9 +225,6 @@ public class DeploymentInstancesSpec extends DeploymentSpec.Step {
         return false;
     }
 
-    /** Returns the rotations configuration of these instances */
-    public List<Endpoint> endpoints() { return endpoints; }
-
     /** Returns the athenz domain if configured */
     public Optional<AthenzDomain> athenzDomain() { return athenzDomain; }
 
@@ -237,6 +237,13 @@ public class DeploymentInstancesSpec extends DeploymentSpec.Step {
                                              .orElse(this.athenzService.orElse(null));
         return Optional.ofNullable(athenzService);
     }
+
+    /** Returns the notification configuration of these instances */
+    public Notifications notifications() { return notifications; }
+
+    /** Returns the rotations configuration of these instances */
+    public List<Endpoint> endpoints() { return endpoints; }
+
     /** Returns whether this instances deployment specifies the given zone, either implicitly or explicitly */
     public boolean includes(Environment environment, Optional<RegionName> region) {
         for (DeploymentSpec.Step step : steps)
@@ -254,12 +261,19 @@ public class DeploymentInstancesSpec extends DeploymentSpec.Step {
                changeBlockers.equals(other.changeBlockers) &&
                steps.equals(other.steps) &&
                athenzDomain.equals(other.athenzDomain) &&
-               athenzService.equals(other.athenzService);
+               athenzService.equals(other.athenzService) &&
+               notifications.equals(other.notifications) &&
+               endpoints.equals(other.endpoints);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(globalServiceId, upgradePolicy, changeBlockers, steps, athenzDomain, athenzService);
+        return Objects.hash(globalServiceId, upgradePolicy, changeBlockers, steps, athenzDomain, athenzService, notifications, endpoints);
+    }
+
+    @Override
+    public String toString() {
+        return "instance" + ( ids.size() < 1 ? " " : "s " ) + ids;
     }
 
 }
diff --git a/config-model-api/src/main/java/com/yahoo/config/application/api/DeploymentSpec.java b/config-model-api/src/main/java/com/yahoo/config/application/api/DeploymentSpec.java
index 7a554cbb749..4079fbf2fbb 100644
--- a/config-model-api/src/main/java/com/yahoo/config/application/api/DeploymentSpec.java
+++ b/config-model-api/src/main/java/com/yahoo/config/application/api/DeploymentSpec.java
@@ -49,16 +49,13 @@ public class DeploymentSpec {
                                                                   List.of());
 
     private final List<Step> steps;
-    private final Notifications notifications;
     private final Optional<Integer> majorVersion;
     private final String xmlForm;
 
     public DeploymentSpec(List<Step> steps,
-                          Notifications notifications,
                           Optional<Integer> majorVersion,
                           String xmlForm) {
         this.steps = steps;
-        this.notifications = notifications;
         this.majorVersion = majorVersion;
         this.xmlForm = xmlForm;
         validateTotalDelay(steps);
@@ -77,8 +74,8 @@ public class DeploymentSpec {
                                                  globalServiceId,
                                                  athenzDomain,
                                                  athenzService,
+                                                 notifications,
                                                  endpoints)),
-             notifications,
              majorVersion,
              xmlForm);
     }
@@ -95,7 +92,8 @@ public class DeploymentSpec {
     private DeploymentInstancesSpec defaultInstance() {
         if (hasDefaultInstanceStepOnly()) return (DeploymentInstancesSpec)steps.get(0);
         throw new IllegalArgumentException("This deployment spec does not support the legacy API " +
-                                           "as it does not consist only of a default instance");
+                                           "as it does not consist only of a default instance. Content: " +
+                                           steps.stream().map(Step::toString).collect(Collectors.joining(",")));
     }
 
     // TODO: Remove after October 2019
@@ -136,31 +134,28 @@ public class DeploymentSpec {
                                        .collect(Collectors.toList());
     }
 
-    /** Returns the notification configuration */
-    public Notifications notifications() { return notifications; }
-
-    /** Returns the rotations configuration */
-    // TODO: Remove after October 2019
-    public List<Endpoint> endpoints() { return defaultInstance().endpoints(); }
-
-    /** Returns the athenz domain if configured */
     // TODO: Remove after October 2019
     public Optional<AthenzDomain> athenzDomain() { return defaultInstance().athenzDomain(); }
 
-    /** Returns the athenz service for environment/region if configured */
     // TODO: Remove after October 2019
     public Optional<AthenzService> athenzService(Environment environment, RegionName region) {
         return defaultInstance().athenzService(environment, region);
     }
 
     // TODO: Remove after October 2019
-    public boolean includes(Environment environment, Optional<RegionName> region) {
-        return defaultInstance().deploysTo(environment, region);
-    }
+    public Notifications notifications() { return defaultInstance().notifications(); }
+
+    // TODO: Remove after October 2019
+    public List<Endpoint> endpoints() { return defaultInstance().endpoints(); }
 
     /** Returns the XML form of this spec, or null if it was not created by fromXml, nor is empty */
     public String xmlForm() { return xmlForm; }
 
+    // TODO: Remove after October 2019
+    public boolean includes(Environment environment, Optional<RegionName> region) {
+        return defaultInstance().deploysTo(environment, region);
+    }
+
     /**
      * Creates a deployment spec from XML.
      *
@@ -212,13 +207,12 @@ public class DeploymentSpec {
         DeploymentSpec other = (DeploymentSpec) o;
         return majorVersion.equals(other.majorVersion) &&
                steps.equals(other.steps) &&
-               xmlForm.equals(other.xmlForm) &&
-               notifications.equals(other.notifications);
+               xmlForm.equals(other.xmlForm);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(majorVersion, steps, xmlForm, notifications);
+        return Objects.hash(majorVersion, steps, xmlForm);
     }
 
     /** This may be invoked by a continuous build */
@@ -361,21 +355,30 @@ public class DeploymentSpec {
 
     }
 
-    /** A deployment step which is to run deployment to multiple zones in parallel */
+    /** A deployment step which is to run multiple steps (zones or instances) in parallel */
     public static class ParallelZones extends Step {
 
-        private final List<DeclaredZone> zones;
+        private final List<Step> steps;
 
-        public ParallelZones(List<DeclaredZone> zones) {
-            this.zones = List.copyOf(zones);
+        public ParallelZones(List<Step> steps) {
+            this.steps = List.copyOf(steps);
         }
 
+        /** Returns the steps inside this which are zones */
         @Override
-        public List<DeclaredZone> zones() { return this.zones; }
+        public List<DeclaredZone> zones() {
+            return this.steps.stream()
+                             .filter(step -> step instanceof DeclaredZone)
+                             .map(DeclaredZone.class::cast)
+                             .collect(Collectors.toList());
+        }
+
+        /** Returns all the steps nested in this */
+        public List<Step> steps() { return steps; }
 
         @Override
         public boolean deploysTo(Environment environment, Optional<RegionName> region) {
-            return zones.stream().anyMatch(zone -> zone.deploysTo(environment, region));
+            return zones().stream().anyMatch(zone -> zone.deploysTo(environment, region));
         }
 
         @Override
@@ -383,13 +386,14 @@ public class DeploymentSpec {
             if (this == o) return true;
             if (!(o instanceof ParallelZones)) return false;
             ParallelZones that = (ParallelZones) o;
-            return Objects.equals(zones, that.zones);
+            return Objects.equals(steps, that.steps);
         }
 
         @Override
         public int hashCode() {
-            return Objects.hash(zones);
+            return Objects.hash(steps);
         }
+
     }
 
     /** Controls when this application will be upgraded to new Vespa versions */
diff --git a/config-model-api/src/main/java/com/yahoo/config/application/api/xml/DeploymentSpecXmlReader.java b/config-model-api/src/main/java/com/yahoo/config/application/api/xml/DeploymentSpecXmlReader.java
index 72a806bb7be..acecb320b83 100644
--- a/config-model-api/src/main/java/com/yahoo/config/application/api/xml/DeploymentSpecXmlReader.java
+++ b/config-model-api/src/main/java/com/yahoo/config/application/api/xml/DeploymentSpecXmlReader.java
@@ -1,6 +1,7 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.config.application.api.xml;
 
+import com.yahoo.config.application.api.DeploymentInstancesSpec;
 import com.yahoo.config.application.api.DeploymentSpec;
 import com.yahoo.config.application.api.DeploymentSpec.DeclaredZone;
 import com.yahoo.config.application.api.DeploymentSpec.Delay;
@@ -14,6 +15,7 @@ import com.yahoo.config.application.api.TimeWindow;
 import com.yahoo.config.provision.AthenzDomain;
 import com.yahoo.config.provision.AthenzService;
 import com.yahoo.config.provision.Environment;
+import com.yahoo.config.provision.InstanceName;
 import com.yahoo.config.provision.RegionName;
 import com.yahoo.io.IOUtils;
 import com.yahoo.text.XML;
@@ -38,27 +40,32 @@ import java.util.stream.Collectors;
  */
 public class DeploymentSpecXmlReader {
 
+    private static final String instanceTag = "instance";
     private static final String majorVersionTag = "major-version";
     private static final String testTag = "test";
     private static final String stagingTag = "staging";
     private static final String blockChangeTag = "block-change";
     private static final String prodTag = "prod";
+    private static final String regionTag = "region";
+    private static final String delayTag = "delay";
+    private static final String parallelTag = "parallel";
     private static final String endpointsTag = "endpoints";
     private static final String endpointTag = "endpoint";
 
+    private static final String athenzServiceAttribute = "athenz-service";
+    private static final String testerFlavorAttribute = "tester-flavor";
+
     private final boolean validate;
 
-    /**
-     * Creates a validating reader
-     */
+    /** Creates a validating reader */
     public DeploymentSpecXmlReader() {
         this(true);
     }
 
     /**
-     * Creates a reader
+     * Creates a deployment spec reader
      *
-     * @param validate true to validate the input, false to accept any input which can be unabiguously parsed
+     * @param validate true to validate the input, false to accept any input which can be unambiguously parsed
      */
     public DeploymentSpecXmlReader(boolean validate) {
         this.validate = validate;
@@ -73,63 +80,102 @@ public class DeploymentSpecXmlReader {
         }
     }
 
-    /**
-     * Reads a deployment spec from XML
-     */
+    /** Reads a deployment spec from XML */
     public DeploymentSpec read(String xmlForm) {
-        List<Step> steps = new ArrayList<>();
-        Optional<String> globalServiceId = Optional.empty();
         Element root = XML.getDocument(xmlForm).getDocumentElement();
-        if (validate)
-            validateTagOrder(root);
-        for (Element environmentTag : XML.getChildren(root)) {
-            if (!isEnvironmentName(environmentTag.getTagName())) continue;
-
-            Environment environment = Environment.from(environmentTag.getTagName());
-            Optional<AthenzService> athenzService = stringAttribute("athenz-service", environmentTag).map(AthenzService::from);
-            Optional<String> testerFlavor = stringAttribute("tester-flavor", environmentTag);
-
-            if (environment == Environment.prod) {
-                for (Element stepTag : XML.getChildren(environmentTag)) {
-                    if (stepTag.getTagName().equals("delay")) {
-                        steps.add(new Delay(Duration.ofSeconds(longAttribute("hours", stepTag) * 60 * 60 +
-                                                               longAttribute("minutes", stepTag) * 60 +
-                                                               longAttribute("seconds", stepTag))));
-                    }
-                    else if (stepTag.getTagName().equals("parallel")) {
-                        List<DeclaredZone> zones = new ArrayList<>();
-                        for (Element regionTag : XML.getChildren(stepTag)) {
-                            zones.add(readDeclaredZone(environment, athenzService, testerFlavor, regionTag));
-                        }
-                        steps.add(new ParallelZones(zones));
-                    }
-                    else { // a region: deploy step
-                        steps.add(readDeclaredZone(environment, athenzService, testerFlavor, stepTag));
-                    }
-                }
-            }
-            else {
-                steps.add(new DeclaredZone(environment, Optional.empty(), false, athenzService, testerFlavor));
+
+        List<Step> steps = new ArrayList<>();
+        if ( ! hasChildTag(instanceTag, root)) { // deployment spec skipping explicit instance -> "default" instance
+            steps.add(readInstanceContent("default", root));
+        }
+        else {
+            if (hasChildTag(prodTag, root))
+                throw new IllegalArgumentException("A deployment spec cannot have both a <prod> tag and an " +
+                                                   "<instance> tag under the root: " +
+                                                   "Wrap the prod tags inside the appropriate instance");
+
+            for (Element topLevelTag : XML.getChildren(root)) {
+                if (topLevelTag.getTagName().equals(instanceTag))
+                    steps.add(readInstanceContent(topLevelTag.getAttribute("id"), topLevelTag));
+                else
+                    steps.addAll(readNonInstanceSteps(topLevelTag, new MutableOptional<>(), topLevelTag)); // (No global service id here)
             }
+        }
+
+        return new DeploymentSpec(steps,
+                                  optionalIntegerAttribute(majorVersionTag, root),
+                                  xmlForm);
+    }
+
+    /**
+     * Reads the content of an (implicit or explicit) instance tag producing an instances step
+     *
+     * @param instanceIdString a comma-separated list of the ids of the instance id(s) this is for
+     * @param instanceElement the element having the content of this instance
+     */
+    private DeploymentInstancesSpec readInstanceContent(String instanceIdString, Element instanceElement) {
+        if (validate)
+            validateTagOrder(instanceElement);
 
-            if (environment == Environment.prod)
-                globalServiceId = readGlobalServiceId(environmentTag);
-            else if (readGlobalServiceId(environmentTag).isPresent())
-                throw new IllegalArgumentException("Attribute 'global-service-id' is only valid on 'prod' tag.");
+        List<InstanceName> instanceNames = Arrays.stream(instanceIdString.split("'"))
+                                                 .map(InstanceName::from)
+                                                 .collect(Collectors.toList());
+        MutableOptional<String> globalServiceId = new MutableOptional<>(); // Deprecated: Set of prod, but belongs to instance
+        Optional<AthenzDomain> athenzDomain = stringAttribute("athenz-domain", instanceElement).map(AthenzDomain::from);
+        Optional<AthenzService> athenzService = stringAttribute("athenz-service", instanceElement).map(AthenzService::from);
 
+        List<Step> steps = new ArrayList<>();
+        for (Element instanceChild : XML.getChildren(instanceElement))
+            steps.addAll(readNonInstanceSteps(instanceChild, globalServiceId, instanceChild));
+
+        return new DeploymentInstancesSpec(instanceNames,
+                                          steps,
+                                          readUpgradePolicy(instanceElement),
+                                          readChangeBlockers(instanceElement),
+                                          globalServiceId.asOptional(),
+                                          athenzDomain,
+                                          athenzService,
+                                          readNotifications(instanceElement),
+                                          readEndpoints(instanceElement));
+    }
+
+    // Consume the give tag as 0-N steps. 0 if it is not a step, >1 if it contains multiple nested steps that should be flattened
+    private List<Step> readNonInstanceSteps(Element stepTag, MutableOptional<String> globalServiceId, Element parentTag) {
+        Optional<AthenzService> athenzService = stringAttribute(athenzServiceAttribute, stepTag)
+                                                        .or(() -> stringAttribute(athenzServiceAttribute, parentTag))
+                                                        .map(AthenzService::from);
+        Optional<String> testerFlavor = stringAttribute(testerFlavorAttribute, stepTag)
+                                                .or(() -> stringAttribute(testerFlavorAttribute, parentTag));
+
+        if (prodTag.equals(stepTag.getTagName()))
+            globalServiceId.set(readGlobalServiceId(stepTag));
+        else if (readGlobalServiceId(stepTag).isPresent())
+            throw new IllegalArgumentException("Attribute 'global-service-id' is only valid on 'prod' tag.");
+
+        switch (stepTag.getTagName()) {
+            case testTag: case stagingTag:
+                return List.of(new DeclaredZone(Environment.from(stepTag.getTagName()), Optional.empty(), false, athenzService, testerFlavor));
+            case prodTag: // regions, delay and parallel may be nested within, but we can flatten them
+                return XML.getChildren(stepTag).stream()
+                                               .flatMap(child -> readNonInstanceSteps(child, globalServiceId, stepTag).stream())
+                                               .collect(Collectors.toList());
+            case delayTag:
+                return List.of(new Delay(Duration.ofSeconds(longAttribute("hours", stepTag) * 60 * 60 +
+                                                            longAttribute("minutes", stepTag) * 60 +
+                                                            longAttribute("seconds", stepTag))));
+            case parallelTag: // regions and instances may be nested within
+                return List.of(new ParallelZones(XML.getChildren(stepTag).stream()
+                                                                         .flatMap(child -> readNonInstanceSteps(child, globalServiceId, stepTag).stream())
+                                                                         .collect(Collectors.toList())));
+            case regionTag:
+                return List.of(readDeclaredZone(Environment.prod, athenzService, testerFlavor, stepTag));
+            default:
+                return List.of();
         }
-        Optional<AthenzDomain> athenzDomain = stringAttribute("athenz-domain", root).map(AthenzDomain::from);
-        Optional<AthenzService> athenzService = stringAttribute("athenz-service", root).map(AthenzService::from);
-        return new DeploymentSpec(globalServiceId,
-                                  readUpgradePolicy(root),
-                                  optionalIntegerAttribute(majorVersionTag, root),
-                                  readChangeBlockers(root),
-                                  steps,
-                                  xmlForm,
-                                  athenzDomain,
-                                  athenzService,
-                                  readNotifications(root),
-                                  readEndpoints(root));
+    }
+
+    private boolean hasChildTag(String childTagName, Element parent) {
+        return XML.getChildren(parent).stream().anyMatch(child -> child.getTagName().equals(childTagName));
     }
 
     private Notifications readNotifications(Element root) {
@@ -159,15 +205,15 @@ public class DeploymentSpecXmlReader {
     }
 
     private List<Endpoint> readEndpoints(Element root) {
-        final var endpointsElement = XML.getChild(root, endpointsTag);
+        var endpointsElement = XML.getChild(root, endpointsTag);
         if (endpointsElement == null) { return Collections.emptyList(); }
 
-        final var endpoints = new LinkedHashMap<String, Endpoint>();
+        var endpoints = new LinkedHashMap<String, Endpoint>();
 
         for (var endpointElement : XML.getChildren(endpointsElement, endpointTag)) {
-            final Optional<String> rotationId = stringAttribute("id", endpointElement);
-            final Optional<String> containerId = stringAttribute("container-id", endpointElement);
-            final var regions = new HashSet<String>();
+            Optional<String> rotationId = stringAttribute("id", endpointElement);
+            Optional<String> containerId = stringAttribute("container-id", endpointElement);
+            var regions = new HashSet<String>();
 
             if (containerId.isEmpty()) {
                 throw new IllegalArgumentException("Missing 'container-id' from 'endpoint' tag.");
@@ -255,10 +301,6 @@ public class DeploymentSpecXmlReader {
         return Optional.ofNullable(value).filter(s -> !s.equals(""));
     }
 
-    private boolean isEnvironmentName(String tagName) {
-        return tagName.equals(testTag) || tagName.equals(stagingTag) || tagName.equals(prodTag);
-    }
-
     private DeclaredZone readDeclaredZone(Environment environment, Optional<AthenzService> athenzService,
                                           Optional<String> testerFlavor, Element regionTag) {
         return new DeclaredZone(environment, Optional.of(RegionName.from(XML.getValue(regionTag).trim())),
@@ -324,4 +366,14 @@ public class DeploymentSpecXmlReader {
                                            "to control whether the region should receive production traffic");
     }
 
+    private static class MutableOptional<T> {
+
+        private Optional<T> value = Optional.empty();
+
+        public void set(Optional<T> value) { this.value = value; }
+
+        public Optional<T> asOptional() { return value; }
+
+    }
+
 }
diff --git a/config-model-api/src/test/java/com/yahoo/config/application/api/DeploymentSpecTest.java b/config-model-api/src/test/java/com/yahoo/config/application/api/DeploymentSpecTest.java
index 694917e1bff..c99a3be7303 100644
--- a/config-model-api/src/test/java/com/yahoo/config/application/api/DeploymentSpecTest.java
+++ b/config-model-api/src/test/java/com/yahoo/config/application/api/DeploymentSpecTest.java
@@ -32,9 +32,9 @@ public class DeploymentSpecTest {
     @Test
     public void testSpec() {
         String specXml = "<deployment version='1.0'>" +
-                         "   <instances name='default'>" +
+                         "   <instance id='default'>" +
                          "      <test/>" +
-                         "   </instances>" +
+                         "   </instance>" +
                          "</deployment>";
 
         StringReader r = new StringReader(specXml);
@@ -53,9 +53,9 @@ public class DeploymentSpecTest {
     @Test
     public void testSpecPinningMajorVersion() {
         String specXml = "<deployment version='1.0' major-version='6'>" +
-                         "   <instances name='default'>" +
+                         "   <instance id='default'>" +
                          "      <test/>" +
-                         "   </instances>" +
+                         "   </instance>" +
                          "</deployment>";
 
         StringReader r = new StringReader(specXml);
@@ -70,9 +70,9 @@ public class DeploymentSpecTest {
     public void stagingSpec() {
         StringReader r = new StringReader(
         "<deployment version='1.0'>" +
-        "   <instances name='default'>" +
+        "   <instance id='default'>" +
         "      <staging/>" +
-        "   </instances>" +
+        "   </instance>" +
         "</deployment>"
         );
 
@@ -91,12 +91,12 @@ public class DeploymentSpecTest {
     public void minimalProductionSpec() {
         StringReader r = new StringReader(
                 "<deployment version='1.0'>" +
-                "   <instances name='default'>" +
+                "   <instance id='default'>" +
                 "      <prod>" +
                 "         <region active='false'>us-east1</region>" +
                 "         <region active='true'>us-west1</region>" +
                 "      </prod>" +
-                "   </instances>" +
+                "   </instance>" +
                 "</deployment>"
         );
 
@@ -128,7 +128,7 @@ public class DeploymentSpecTest {
     public void maximalProductionSpec() {
         StringReader r = new StringReader(
         "<deployment version='1.0'>" +
-        "   <instances name='default'>" +
+        "   <instance id='default'>" +
         "      <test/>" +
         "      <staging/>" +
         "      <prod>" +
@@ -136,7 +136,7 @@ public class DeploymentSpecTest {
         "         <delay hours='3' minutes='30'/>" +
         "         <region active='true'>us-west1</region>" +
         "      </prod>" +
-        "   </instances>" +
+        "   </instance>" +
         "</deployment>"
         );
 
@@ -170,12 +170,12 @@ public class DeploymentSpecTest {
     public void productionSpecWithGlobalServiceId() {
         StringReader r = new StringReader(
             "<deployment version='1.0'>" +
-            "   <instances name='default'>" +
+            "   <instance id='default'>" +
             "      <prod global-service-id='query'>" +
             "         <region active='true'>us-east-1</region>" +
             "         <region active='true'>us-west-1</region>" +
             "      </prod>" +
-            "   </instances>" +
+            "   </instance>" +
             "</deployment>"
         );
 
@@ -187,9 +187,9 @@ public class DeploymentSpecTest {
     public void globalServiceIdInTest() {
         StringReader r = new StringReader(
                 "<deployment version='1.0'>" +
-                "   <instances name='default'>" +
+                "   <instance id='default'>" +
                 "      <test global-service-id='query' />" +
-                "   </instances>" +
+                "   </instance>" +
                 "</deployment>"
         );
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
@@ -199,9 +199,9 @@ public class DeploymentSpecTest {
     public void globalServiceIdInStaging() {
         StringReader r = new StringReader(
                 "<deployment version='1.0'>" +
-                "   <instances name='default'>" +
+                "   <instance id='default'>" +
                 "      <staging global-service-id='query' />" +
-                "   </instances>" +
+                "   </instance>" +
                 "</deployment>"
         );
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
@@ -211,7 +211,7 @@ public class DeploymentSpecTest {
     public void productionSpecWithGlobalServiceIdBeforeStaging() {
         StringReader r = new StringReader(
             "<deployment>" +
-            "   <instances name='default'>" +
+            "   <instance id='default'>" +
             "      <test/>" +
             "      <prod global-service-id='qrs'>" +
             "         <region active='true'>us-west-1</region>" +
@@ -219,7 +219,7 @@ public class DeploymentSpecTest {
             "         <region active='true'>us-east-3</region>" +
             "      </prod>" +
             "      <staging/>" +
-            "   </instances>" +
+            "   </instance>" +
             "</deployment>"
         );
 
@@ -231,14 +231,14 @@ public class DeploymentSpecTest {
     public void productionSpecWithUpgradePolicy() {
         StringReader r = new StringReader(
                 "<deployment>" +
-                "   <instances name='default'>" +
+                "   <instance id='default'>" +
                 "      <upgrade policy='canary'/>" +
                 "      <prod>" +
                 "         <region active='true'>us-west-1</region>" +
                 "         <region active='true'>us-central-1</region>" +
                 "         <region active='true'>us-east-3</region>" +
                 "      </prod>" +
-                "   </instances>" +
+                "   </instance>" +
                 "</deployment>"
         );
 
@@ -251,7 +251,7 @@ public class DeploymentSpecTest {
         try {
             StringReader r = new StringReader(
                     "<deployment>" +
-                    "   <instances name='default'>" +
+                    "   <instance id='default'>" +
                     "      <upgrade policy='canary'/>" +
                     "      <prod>" +
                     "         <region active='true'>us-west-1</region>" +
@@ -260,7 +260,7 @@ public class DeploymentSpecTest {
                     "         <delay minutes='59' seconds='61'/>" +
                     "         <region active='true'>us-east-3</region>" +
                     "      </prod>" +
-                    "   </instances>" +
+                    "   </instance>" +
                     "</deployment>"
             );
             DeploymentSpec.fromXml(r);
@@ -284,7 +284,7 @@ public class DeploymentSpecTest {
     public void productionSpecWithParallelDeployments() {
         StringReader r = new StringReader(
                 "<deployment>" +
-                "   <instances name='default'>" +
+                "   <instance id='default'>" +
                 "      <prod>" +
                 "         <region active='true'>us-west-1</region>" +
                 "         <parallel>" +
@@ -292,7 +292,7 @@ public class DeploymentSpecTest {
                 "            <region active='true'>us-east-3</region>" +
                 "         </parallel>" +
                 "      </prod>" +
-                "   </instances>" +
+                "   </instance>" +
                 "</deployment>"
         );
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
@@ -306,7 +306,7 @@ public class DeploymentSpecTest {
     public void productionSpecWithDuplicateRegions() {
         StringReader r = new StringReader(
                 "<deployment>" +
-                "   <instances name='default'>" +
+                "   <instance id='default'>" +
                 "      <prod>" +
                 "         <region active='true'>us-west-1</region>" +
                 "         <parallel>" +
@@ -315,7 +315,7 @@ public class DeploymentSpecTest {
                 "             <region active='true'>us-east-3</region>" +
                 "         </parallel>" +
                 "      </prod>" +
-                "   </instances>" +
+                "   </instance>" +
                 "</deployment>"
         );
         try {
@@ -330,13 +330,13 @@ public class DeploymentSpecTest {
     public void deploymentSpecWithIllegallyOrderedDeploymentSpec1() {
         StringReader r = new StringReader(
                 "<deployment>" +
-                "   <instances name='default'>" +
+                "   <instance id='default'>" +
                 "      <block-change days='sat' hours='10' time-zone='CET'/>" +
                 "      <prod>" +
                 "         <region active='true'>us-west-1</region>" +
                 "      </prod>" +
                 "      <block-change days='mon,tue' hours='15-16'/>" +
-                "   </instances>" +
+                "   </instance>" +
                 "</deployment>"
         );
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
@@ -346,13 +346,13 @@ public class DeploymentSpecTest {
     public void deploymentSpecWithIllegallyOrderedDeploymentSpec2() {
         StringReader r = new StringReader(
                 "<deployment>\n" +
-                "   <instances name='default'>" +
+                "   <instance id='default'>" +
                 "      <block-change days='sat' hours='10' time-zone='CET'/>" +
                 "      <test/>" +
                 "      <prod>" +
                 "         <region active='true'>us-west-1</region>" +
                 "      </prod>" +
-                "   </instances>" +
+                "   </instance>" +
                 "</deployment>"
         );
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
@@ -362,13 +362,13 @@ public class DeploymentSpecTest {
     public void deploymentSpecWithChangeBlocker() {
         StringReader r = new StringReader(
                 "<deployment>" +
-                "   <instances name='default'>" +
+                "   <instance id='default'>" +
                 "      <block-change revision='false' days='mon,tue' hours='15-16'/>" +
                 "      <block-change days='sat' hours='10' time-zone='CET'/>" +
                 "      <prod>" +
                 "         <region active='true'>us-west-1</region>" +
                 "      </prod>" +
-                "   </instances>" +
+                "   </instance>" +
                 "</deployment>"
         );
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
@@ -395,11 +395,11 @@ public class DeploymentSpecTest {
     public void athenz_config_is_disallowed_on_deployment_if_instances() {
         StringReader r = new StringReader(
                 "<deployment athenz-domain='domain' athenz-service='service''>" +
-                "   <instances name='default'>" +
+                "   <instance id='default'>" +
                 "      <prod>" +
                 "         <region active='true'>us-west-1</region>" +
                 "      </prod>" +
-                "   </instances>" +
+                "   </instance>" +
                 "</deployment>"
         );
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
@@ -408,12 +408,12 @@ public class DeploymentSpecTest {
     @Test
     public void athenz_config_is_read_from_instance() {
         StringReader r = new StringReader(
-                "<deployment'>" +
-                "   <instances name='default' athenz-domain='domain' athenz-service='service'>" +
+                "<deployment>" +
+                "   <instance id='default' athenz-domain='domain' athenz-service='service'>" +
                 "      <prod>" +
                 "         <region active='true'>us-west-1</region>" +
                 "      </prod>" +
-                "   </instances>" +
+                "   </instance>" +
                 "</deployment>"
         );
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
@@ -425,12 +425,12 @@ public class DeploymentSpecTest {
     public void athenz_service_is_overridden_from_environment() {
         StringReader r = new StringReader(
                 "<deployment athenz-domain='domain' athenz-service='service'>" +
-                "   <instances name='default' athenz-domain='domain' athenz-service='service'>" +
+                "   <instance id='default' athenz-domain='domain' athenz-service='service'>" +
                 "      <test/>" +
                 "      <prod athenz-service='prod-service'>" +
                 "         <region active='true'>us-west-1</region>" +
                 "      </prod>" +
-                "   </instances>" +
+                "   </instance>" +
                 "</deployment>"
         );
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
@@ -442,11 +442,11 @@ public class DeploymentSpecTest {
     public void it_fails_when_athenz_service_is_not_defined() {
         StringReader r = new StringReader(
                 "<deployment>" +
-                "   <instances name='default' athenz-domain='domain'>" +
+                "   <instance id='default' athenz-domain='domain'>" +
                 "      <prod>" +
                 "         <region active='true'>us-west-1</region>" +
                 "      </prod>" +
-                "   </instances>" +
+                "   </instance>" +
                 "</deployment>"
         );
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
@@ -456,11 +456,11 @@ public class DeploymentSpecTest {
     public void it_fails_when_athenz_service_is_configured_but_not_athenz_domain() {
         StringReader r = new StringReader(
                 "<deployment>" +
-                "   <instances name='default'>" +
+                "   <instance id='default'>" +
                 "      <prod athenz-service='service'>" +
                 "         <region active='true'>us-west-1</region>" +
                 "      </prod>" +
-                "   </instances>" +
+                "   </instance>" +
                 "</deployment>"
         );
         DeploymentSpec spec = DeploymentSpec.fromXml(r);
@@ -470,16 +470,16 @@ public class DeploymentSpecTest {
     public void noNotifications() {
         assertEquals(Notifications.none(),
                      DeploymentSpec.fromXml("<deployment>" +
-                                            "   <instances name='default'/>" +
+                                            "   <instance id='default'/>" +
                                             "</deployment>").notifications());
     }
 
     @Test
     public void emptyNotifications() {
         DeploymentSpec spec = DeploymentSpec.fromXml("<deployment>" +
-                                                     "   <instances name='default'>" +
+                                                     "   <instance id='default'>" +
                                                      "      <notifications/>" +
-                                                     "   </instances>" +
+                                                     "   </instance>" +
                                                      "</deployment>");
         assertEquals(Notifications.none(),
                      spec.notifications());
@@ -488,13 +488,13 @@ public class DeploymentSpecTest {
     @Test
     public void someNotifications() {
         DeploymentSpec spec = DeploymentSpec.fromXml("<deployment>\n" +
-                                                     "   <instances name='default'>" +
+                                                     "   <instance id='default'>" +
                                                      "      <notifications when=\"failing\">" +
                                                      "         <email role=\"author\"/>" +
                                                      "         <email address=\"john@dev\" when=\"failing-commit\"/>" +
                                                      "         <email address=\"jane@dev\"/>" +
                                                      "      </notifications>" +
-                                                     "   </instances>" +
+                                                     "   </instance>" +
                                                      "</deployment>");
         assertEquals(ImmutableSet.of(author), spec.notifications().emailRolesFor(failing));
         assertEquals(ImmutableSet.of(author), spec.notifications().emailRolesFor(failingCommit));
@@ -505,12 +505,12 @@ public class DeploymentSpecTest {
     @Test
     public void customTesterFlavor() {
         DeploymentSpec spec = DeploymentSpec.fromXml("<deployment>" +
-                                                     "   <instances name='default'>" +
+                                                     "   <instance id='default'>" +
                                                      "      <test tester-flavor=\"d-1-4-20\" />" +
                                                      "      <prod tester-flavor=\"d-2-8-50\">" +
                                                      "         <region active=\"false\">us-north-7</region>" +
                                                      "      </prod>" +
-                                                     "   </instances>" +
+                                                     "   </instance>" +
                                                      "</deployment>");
         assertEquals(Optional.of("d-1-4-20"), spec.steps().get(0).zones().get(0).testerFlavor());
         assertEquals(Optional.empty(), spec.steps().get(1).zones().get(0).testerFlavor());
@@ -521,16 +521,16 @@ public class DeploymentSpecTest {
     public void noEndpoints() {
         assertEquals(Collections.emptyList(),
                      DeploymentSpec.fromXml("<deployment>" +
-                                            "   <instances name='default'/>" +
+                                            "   <instance id='default'/>" +
                                             "</deployment>").endpoints());
     }
 
     @Test
     public void emptyEndpoints() {
         var spec = DeploymentSpec.fromXml("<deployment>" +
-                                          "   <instances name='default'>" +
+                                          "   <instance id='default'>" +
                                           "      <endpoints/>" +
-                                          "   </instances>" +
+                                          "   </instance>" +
                                           "</deployment>");
         assertEquals(Collections.emptyList(), spec.endpoints());
     }
@@ -539,7 +539,7 @@ public class DeploymentSpecTest {
     public void someEndpoints() {
         var spec = DeploymentSpec.fromXml("" +
                                           "<deployment>" +
-                                          "   <instances name='default'>" +
+                                          "   <instance id='default'>" +
                                           "      <prod>" +
                                           "         <region active=\"true\">us-east</region>" +
                                           "      </prod>" +
@@ -550,7 +550,7 @@ public class DeploymentSpecTest {
                                           "         <endpoint id=\"nalle\" container-id=\"frosk\" />" +
                                           "         <endpoint container-id=\"quux\" />" +
                                           "      </endpoints>" +
-                                          "   </instances>" +
+                                          "   </instance>" +
                                           "</deployment>");
 
         assertEquals(
@@ -593,7 +593,7 @@ public class DeploymentSpecTest {
     public void endpointDefaultRegions() {
         var spec = DeploymentSpec.fromXml("" +
                                           "<deployment>" +
-                                          "   <instances name='default'>" +
+                                          "   <instance id='default'>" +
                                           "      <prod>" +
                                           "         <region active=\"true\">us-east</region>" +
                                           "         <region active=\"true\">us-west</region>" +
@@ -605,7 +605,7 @@ public class DeploymentSpecTest {
                                           "      <endpoint id=\"nalle\" container-id=\"frosk\" />" +
                                           "         <endpoint container-id=\"quux\" />" +
                                           "      </endpoints>" +
-                                          "   </instances>" +
+                                          "   </instance>" +
                                           "</deployment>");
 
         assertEquals(Set.of("us-east"), endpointRegions("foo", spec));
@@ -630,14 +630,14 @@ public class DeploymentSpecTest {
 
     private static List<String> endpointIds(String endpointTag) {
         var xml = "<deployment>" +
-                  "   <instances name='default'>" +
+                  "   <instance id='default'>" +
                   "      <prod>" +
                   "         <region active=\"true\">us-east</region>" +
                   "      </prod>" +
                   "      <endpoints>" +
                   endpointTag +
                   "      </endpoints>" +
-                  "   </instances>" +
+                  "   </instance>" +
                   "</deployment>";
 
         return DeploymentSpec.fromXml(xml).endpoints().stream()