Make Application.deploying mandatory

15 files changed, 128 insertions, 107 deletions

diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/Application.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/Application.java
index bb1f64c121c..abfd94f87a2 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/Application.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/Application.java
@@ -42,7 +42,7 @@ public class Application {
     private final ValidationOverrides validationOverrides;
     private final Map<ZoneId, Deployment> deployments;
     private final DeploymentJobs deploymentJobs;
-    private final Optional<Change> deploying;
+    private final Change deploying;
     private final boolean outstandingChange;
     private final Optional<IssueId> ownershipIssueId;
     private final ApplicationMetrics metrics;
@@ -52,13 +52,13 @@ public class Application {
     public Application(ApplicationId id) {
         this(id, DeploymentSpec.empty, ValidationOverrides.empty, Collections.emptyMap(),
              new DeploymentJobs(Optional.empty(), Collections.emptyList(), Optional.empty()),
-             Optional.empty(), false, Optional.empty(), new ApplicationMetrics(0, 0),
+             Change.empty(), false, Optional.empty(), new ApplicationMetrics(0, 0),
              Optional.empty());
     }
 
     /** Used from persistence layer: Do not use */
     public Application(ApplicationId id, DeploymentSpec deploymentSpec, ValidationOverrides validationOverrides,
-                       List<Deployment> deployments, DeploymentJobs deploymentJobs, Optional<Change> deploying,
+                       List<Deployment> deployments, DeploymentJobs deploymentJobs, Change deploying,
                        boolean outstandingChange, Optional<IssueId> ownershipIssueId, ApplicationMetrics metrics,
                        Optional<RotationId> rotation) {
         this(id, deploymentSpec, validationOverrides,
@@ -67,7 +67,7 @@ public class Application {
     }
 
     Application(ApplicationId id, DeploymentSpec deploymentSpec, ValidationOverrides validationOverrides,
-                Map<ZoneId, Deployment> deployments, DeploymentJobs deploymentJobs, Optional<Change> deploying,
+                Map<ZoneId, Deployment> deployments, DeploymentJobs deploymentJobs, Change deploying,
                 boolean outstandingChange, Optional<IssueId> ownershipIssueId, ApplicationMetrics metrics,
                 Optional<RotationId> rotation) {
         Objects.requireNonNull(id, "id cannot be null");
@@ -124,7 +124,7 @@ public class Application {
      * Returns the change that is currently in the process of being deployed on this application,
      * or empty if no change is currently being deployed.
      */
-    public Optional<Change> deploying() { return deploying; }
+    public Change deploying() { return deploying; }
 
     /**
      * Returns whether this has an outstanding change (in the source repository), which
@@ -152,8 +152,8 @@ public class Application {
 
     /** Returns the version a new deployment to this zone should use for this application */
     public Version deployVersionIn(ZoneId zone, Controller controller) {
-        if (deploying().isPresent() && deploying().get() instanceof VersionChange)
-            return ((Change.VersionChange) deploying().get()).version();
+        if (deploying() instanceof VersionChange)
+            return ((Change.VersionChange) deploying()).version();
 
         return versionIn(zone, controller);
     }
@@ -166,8 +166,8 @@ public class Application {
 
     /** Returns the application version a deployment to this zone should use, or empty if we don't know */
     public Optional<ApplicationVersion> deployApplicationVersionIn(ZoneId zone) {
-        if (deploying().isPresent() && deploying().get() instanceof Change.ApplicationChange) {
-            ApplicationVersion version = ((Change.ApplicationChange) deploying().get()).version();
+        if (deploying() instanceof Change.ApplicationChange) {
+            ApplicationVersion version = ((Change.ApplicationChange) deploying()).version();
             if (version == ApplicationVersion.unknown)
                 return Optional.empty();
             else
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/ApplicationController.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/ApplicationController.java
index 603f6c3ad12..dc39268c48d 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/ApplicationController.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/ApplicationController.java
@@ -322,9 +322,9 @@ public class ApplicationController {
             validate(applicationPackage.deploymentSpec());
 
             // TODO: Remove after introducing new application version number
-            if (!options.deployCurrentVersion && applicationPackageFromDeployer.isPresent()) {
-                if (application.deploying().isPresent() && application.deploying().get() instanceof Change.ApplicationChange) {
-                    application = application.withDeploying(Optional.of(Change.ApplicationChange.of(applicationVersion)));
+            if ( ! options.deployCurrentVersion && applicationPackageFromDeployer.isPresent()) {
+                if (application.deploying() instanceof Change.ApplicationChange) {
+                    application = application.withDeploying(Change.ApplicationChange.of(applicationVersion));
                 }
                 if (!canDeployDirectlyTo(zone, options) && jobType.isPresent()) {
                     // Update with (potentially) missing information about what we triggered:
@@ -361,7 +361,7 @@ public class ApplicationController {
             if (!canDeployDirectlyTo(zone, options)) {
                 if (!application.deploymentJobs().isDeployableTo(zone.environment(), application.deploying())) {
                     throw new IllegalArgumentException("Rejecting deployment of " + application + " to " + zone +
-                                                       " as " + application.deploying().get() + " is not tested");
+                                                       " as " + application.deploying() + " is not tested");
                 }
                 Deployment existingDeployment = application.deployments().get(zone);
                 if (zone.environment().isProduction() && existingDeployment != null &&
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/LockedApplication.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/LockedApplication.java
index e84409296dd..9dd849d736a 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/LockedApplication.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/LockedApplication.java
@@ -64,7 +64,7 @@ public class LockedApplication extends Application {
         return new LockedApplication(new Builder(this).with(deploymentJobs().withCompletion(report, notificationTime, controller)));
     }
 
-    public LockedApplication withJobTriggering(JobType type, Optional<Change> change, Instant triggerTime,
+    public LockedApplication withJobTriggering(JobType type, Change change, Instant triggerTime,
                                                Version version, ApplicationVersion applicationVersion,
                                                String reason) {
         return new LockedApplication(new Builder(this).with(deploymentJobs().withTriggering(type, change, version, applicationVersion, reason, triggerTime)));
@@ -119,7 +119,7 @@ public class LockedApplication extends Application {
         return new LockedApplication(new Builder(this).with(validationOverrides));
     }
 
-    public LockedApplication withDeploying(Optional<Change> deploying) {
+    public LockedApplication withDeploying(Change deploying) {
         return new LockedApplication(new Builder(this).withDeploying(deploying));
     }
 
@@ -166,7 +166,7 @@ public class LockedApplication extends Application {
         private ValidationOverrides validationOverrides;
         private Map<ZoneId, Deployment> deployments;
         private DeploymentJobs deploymentJobs;
-        private Optional<Change> deploying;
+        private Change deploying;
         private boolean hasOutstandingChange;
         private Optional<IssueId> ownershipIssueId;
         private ApplicationMetrics metrics;
@@ -205,7 +205,7 @@ public class LockedApplication extends Application {
             return this;
         }
 
-        private Builder withDeploying(Optional<Change> deploying) {
+        private Builder withDeploying(Change deploying) {
             this.deploying = deploying;
             return this;
         }
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/application/ApplicationList.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/application/ApplicationList.java
index f8c7319fabc..dd7c238053c 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/application/ApplicationList.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/application/ApplicationList.java
@@ -17,7 +17,7 @@ import java.util.stream.Stream;
 
 /**
  * A list of applications which can be filtered in various ways.
- * 
+ *
  * @author bratseth
  */
 public class ApplicationList {
@@ -27,9 +27,9 @@ public class ApplicationList {
     private ApplicationList(Iterable<Application> applications) {
         this.list = ImmutableList.copyOf(applications);
     }
-    
+
     // ----------------------------------- Factories
-    
+
     public static ApplicationList from(Iterable<Application> applications) {
         return new ApplicationList(applications);
     }
@@ -67,7 +67,7 @@ public class ApplicationList {
         return listOf(list.stream().filter(application -> ! isUpgradingTo(version, application)));
     }
 
-    /** 
+    /**
      * Returns the subset of applications which are currently not upgrading to the given version,
      * or returns all if no version is specified
      */
@@ -125,7 +125,7 @@ public class ApplicationList {
     public ApplicationList without(UpgradePolicy policy) {
         return listOf(list.stream().filter(a ->  a.deploymentSpec().upgradePolicy() != policy));
     }
-    
+
     /** Returns the subset of applications which have at least one deployment on a lower version than the given one */
     public ApplicationList onLowerVersionThan(Version version) {
         return listOf(list.stream()
@@ -134,7 +134,7 @@ public class ApplicationList {
     }
 
     /**
-     * Returns the subset of applications which are not pull requests: 
+     * Returns the subset of applications which are not pull requests:
      * Pull requests changes the application instance name to (default-pr)?[pull-request-number]
      */
     public ApplicationList notPullRequest() {
@@ -172,14 +172,14 @@ public class ApplicationList {
 
     private static boolean isUpgrading(Application application) {
         if ( ! (application.deploying().isPresent()) ) return false;
-        if ( ! (application.deploying().get() instanceof Change.VersionChange) ) return false;
+        if ( ! (application.deploying() instanceof Change.VersionChange) ) return false;
         return true;
     }
 
     private static boolean isUpgradingTo(Version version, Application application) {
         if ( ! (application.deploying().isPresent()) ) return false;
-        if ( ! (application.deploying().get() instanceof Change.VersionChange) ) return false;
-        return ((Change.VersionChange)application.deploying().get()).version().equals(version);
+        if ( ! (application.deploying() instanceof Change.VersionChange) ) return false;
+        return ((Change.VersionChange)application.deploying()).version().equals(version);
     }
 
     private static boolean failingOn(Version version, Application application) {
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/application/Change.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/application/Change.java
index aeed510fa7e..5e3952f5ad7 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/application/Change.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/application/Change.java
@@ -14,9 +14,29 @@ import java.util.Objects;
  */
 public abstract class Change {
 
+    private static NoChange none = new NoChange();
+
     /** Returns true if this change is blocked by the given spec at the given instant */
     public abstract boolean blockedBy(DeploymentSpec deploymentSpec, Instant instant);
 
+    public abstract boolean isPresent();
+
+    public static Change empty() { return none; }
+
+    public static class NoChange extends Change {
+
+        private NoChange() { }
+
+        @Override
+        public boolean isPresent() { return false; }
+
+        @Override
+        public boolean blockedBy(DeploymentSpec deploymentSpec, Instant instant) {
+            return false;
+        }
+
+    }
+
     /** A change to the application package version of an application */
     public static class ApplicationChange extends Change {
 
@@ -27,6 +47,9 @@ public abstract class Change {
             this.version = version;
         }
 
+        @Override
+        public boolean isPresent() { return true; }
+
         /** The application package version in this change, or empty if not known yet */
         public ApplicationVersion version() { return version; }
 
@@ -76,6 +99,9 @@ public abstract class Change {
             this.version = version;
         }
 
+        @Override
+        public boolean isPresent() { return true; }
+
         /** The Vespa version this changes to */
         public Version version() { return version; }
 
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/application/DeploymentJobs.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/application/DeploymentJobs.java
index 677f7809c33..542343d66c0 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/application/DeploymentJobs.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/application/DeploymentJobs.java
@@ -65,7 +65,7 @@ public class DeploymentJobs {
     }
 
     public DeploymentJobs withTriggering(JobType jobType,
-                                         Optional<Change> change,
+                                         Change change,
                                          Version version,
                                          ApplicationVersion applicationVersion,
                                          String reason,
@@ -75,7 +75,7 @@ public class DeploymentJobs {
             if (job == null) job = JobStatus.initial(jobType);
             return job.withTriggering(version,
                                       applicationVersion,
-                                      change.isPresent() && change.get() instanceof Change.VersionChange,
+                                      change instanceof Change.VersionChange,
                                       reason,
                                       triggerTime);
         });
@@ -117,14 +117,14 @@ public class DeploymentJobs {
     }
 
     /** Returns whether change can be deployed to the given environment */
-    public boolean isDeployableTo(Environment environment, Optional<Change> change) {
+    public boolean isDeployableTo(Environment environment, Change change) {
         if (environment == null || ! change.isPresent()) {
             return true;
         }
         if (environment == Environment.staging) {
-            return isSuccessful(change.get(), JobType.systemTest);
+            return isSuccessful(change, JobType.systemTest);
         } else if (environment == Environment.prod) {
-            return isSuccessful(change.get(), JobType.stagingTest);
+            return isSuccessful(change, JobType.stagingTest);
         }
         return true; // other environments do not have any preconditions
     }
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/deployment/DeploymentTrigger.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/deployment/DeploymentTrigger.java
index f02b46fdbb1..18838f243ad 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/deployment/DeploymentTrigger.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/deployment/DeploymentTrigger.java
@@ -87,8 +87,7 @@ public class DeploymentTrigger {
                 if (report.jobType() == JobType.component) {
                     if (acceptNewApplicationVersionNow(application)) {
                         // Set this as the change we are doing, unless we are already pushing a platform change
-                        if ( ! ( application.deploying().isPresent() &&
-                                 application.deploying().get() instanceof Change.VersionChange)) {
+                        if ( ! ( application.deploying() instanceof Change.VersionChange)) {
                             Change.ApplicationChange applicationChange = Change.ApplicationChange.unknown();
                             // TODO: Remove guard when source is always reported by component
                             if (report.sourceRevision().isPresent()) {
@@ -97,7 +96,7 @@ public class DeploymentTrigger {
                                                                 report.buildNumber())
                                 );
                             }
-                            application = application.withDeploying(Optional.of(applicationChange));
+                            application = application.withDeploying(applicationChange);
                         }
                     }
                     else { // postpone
@@ -107,7 +106,7 @@ public class DeploymentTrigger {
                 }
                 else if (deploymentComplete(application)) {
                     // change completed
-                    application = application.withDeploying(Optional.empty());
+                    application = application.withDeploying(Change.empty());
                 }
             }
 
@@ -129,7 +128,7 @@ public class DeploymentTrigger {
     /** Returns whether all production zones listed in deployment spec has this change (or a newer version, if upgrade) */
     private boolean deploymentComplete(LockedApplication application) {
         if ( ! application.deploying().isPresent()) return true;
-        Change change = application.deploying().get();
+        Change change = application.deploying();
 
         for (JobType job : order.jobsFrom(application.deploymentSpec())) {
             if ( ! job.isProduction()) continue;
@@ -173,8 +172,8 @@ public class DeploymentTrigger {
         // Should the first step be triggered?
         if ( ! jobs.isEmpty() && jobs.get(0).equals(JobType.systemTest) ) {
             JobStatus systemTestStatus = application.deploymentJobs().jobStatus().get(JobType.systemTest);
-            if (application.deploying().get() instanceof Change.VersionChange) {
-                Version target = ((Change.VersionChange) application.deploying().get()).version();
+            if (application.deploying() instanceof Change.VersionChange) {
+                Version target = ((Change.VersionChange) application.deploying()).version();
                 if (systemTestStatus == null
                     || ! systemTestStatus.lastTriggered().isPresent()
                     || ! systemTestStatus.isSuccess()
@@ -220,7 +219,7 @@ public class DeploymentTrigger {
         if ( ! application.deploying().isPresent()) return false;
         if (next == null) return true;
 
-        Change change = application.deploying().get();
+        Change change = application.deploying();
 
         if (change instanceof Change.VersionChange) { // Propagate upgrade while making sure we never downgrade
             Version targetVersion = ((Change.VersionChange)change).version();
@@ -270,8 +269,8 @@ public class DeploymentTrigger {
         applications().lockOrThrow(applicationId, application -> {
             if (application.deploying().isPresent()  && ! application.deploymentJobs().hasFailures())
                 throw new IllegalArgumentException("Could not start " + change + " on " + application + ": " +
-                                                   application.deploying().get() + " is already in progress");
-            application = application.withDeploying(Optional.of(change));
+                                                   application.deploying() + " is already in progress");
+            application = application.withDeploying(change);
             if (change instanceof Change.ApplicationChange)
                 application = application.withOutstandingChange(false);
             application = trigger(JobType.systemTest, application, false,
@@ -288,7 +287,7 @@ public class DeploymentTrigger {
     public void cancelChange(ApplicationId applicationId) {
         applications().lockOrThrow(applicationId, application -> {
             buildSystem.removeJobs(application.id());
-            applications().store(application.withDeploying(Optional.empty()));
+            applications().store(application.withDeploying(Change.empty()));
         });
     }
 
@@ -360,7 +359,7 @@ public class DeploymentTrigger {
 
         if ( ! force && ! allowedTriggering(jobType, application)) return application;
         log.info(String.format("Triggering %s for %s, %s: %s", jobType, application,
-                               application.deploying().map(d -> "deploying " + d).orElse("restarted deployment"),
+                               application.deploying().isPresent() ? "deploying " + application.deploying() : "restarted deployment",
                                reason));
         buildSystem.addJob(application.id(), jobType, first);
         return application.withJobTriggering(jobType,
@@ -379,11 +378,11 @@ public class DeploymentTrigger {
         //       fix to a version upgrade, so not doing it now
 
         if (jobType.isProduction() && application.deploying().isPresent() &&
-            application.deploying().get().blockedBy(application.deploymentSpec(), clock.instant())) return false;
+            application.deploying().blockedBy(application.deploymentSpec(), clock.instant())) return false;
 
         // Don't downgrade or redeploy the same version in production needlessly
-        if (application.deploying().isPresent() && application.deploying().get() instanceof VersionChange &&
-            jobType.isProduction() && alreadyDeployed(((VersionChange) application.deploying().get()).version(), application, jobType)) return false;
+        if (application.deploying() instanceof VersionChange &&
+            jobType.isProduction() && alreadyDeployed(((VersionChange) application.deploying()).version(), application, jobType)) return false;
 
         if (application.deploymentJobs().isRunning(jobType, jobTimeoutLimit())) return false;
         if  ( ! hasJob(jobType, application)) return false;
@@ -419,7 +418,7 @@ public class DeploymentTrigger {
     private boolean acceptNewApplicationVersionNow(LockedApplication application) {
         if ( ! application.deploying().isPresent()) return true;
 
-        if (application.deploying().get() instanceof Change.ApplicationChange) return true; // more changes are ok
+        if (application.deploying() instanceof Change.ApplicationChange) return true; // more changes are ok
 
         if (application.deploymentJobs().hasFailures()) return true; // allow changes to fix upgrade problems
 
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/persistence/ApplicationSerializer.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/persistence/ApplicationSerializer.java
index 0747d24a80a..b626fda5be1 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/persistence/ApplicationSerializer.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/persistence/ApplicationSerializer.java
@@ -243,14 +243,14 @@ public class ApplicationSerializer {
         object.setLong(atField, jobRun.get().at().toEpochMilli());
     }
 
-    private void toSlime(Optional<Change> deploying, Cursor parentObject) {
+    private void toSlime(Change deploying, Cursor parentObject) {
         if ( ! deploying.isPresent()) return;
 
         Cursor object = parentObject.setObject(deployingField);
-        if (deploying.get() instanceof Change.VersionChange)
-            object.setString(versionField, ((Change.VersionChange)deploying.get()).version().toString());
-        else if (((Change.ApplicationChange)deploying.get()).version() != ApplicationVersion.unknown)
-            toSlime(((Change.ApplicationChange)deploying.get()).version(), object);
+        if (deploying instanceof Change.VersionChange)
+            object.setString(versionField, ((Change.VersionChange)deploying).version().toString());
+        else if (((Change.ApplicationChange)deploying).version() != ApplicationVersion.unknown)
+            toSlime(((Change.ApplicationChange)deploying).version(), object);
     }
 
     // ------------------ Deserialization
@@ -263,7 +263,7 @@ public class ApplicationSerializer {
         ValidationOverrides validationOverrides = ValidationOverrides.fromXml(root.field(validationOverridesField).asString());
         List<Deployment> deployments = deploymentsFromSlime(root.field(deploymentsField));
         DeploymentJobs deploymentJobs = deploymentJobsFromSlime(root.field(deploymentJobsField));
-        Optional<Change> deploying = changeFromSlime(root.field(deployingField));
+        Change deploying = changeFromSlime(root.field(deployingField));
         boolean outstandingChange = root.field(outstandingChangeField).asBool();
         Optional<IssueId> ownershipIssueId = optionalString(root.field(ownershipIssueIdField)).map(IssueId::from);
         ApplicationMetrics metrics = new ApplicationMetrics(root.field(queryQualityField).asDouble(),
@@ -363,15 +363,15 @@ public class ApplicationSerializer {
         return new DeploymentJobs(projectId, jobStatusList, issueId);
     }
 
-    private Optional<Change> changeFromSlime(Inspector object) {
-        if ( ! object.valid()) return Optional.empty();
+    private Change changeFromSlime(Inspector object) {
+        if ( ! object.valid()) return Change.empty();
         Inspector versionFieldValue = object.field(versionField);
         if (versionFieldValue.valid())
-            return Optional.of(new Change.VersionChange(Version.fromString(versionFieldValue.asString())));
+            return new Change.VersionChange(Version.fromString(versionFieldValue.asString()));
         else if (object.field(applicationPackageHashField).valid())
-            return Optional.of(Change.ApplicationChange.of(applicationVersionFromSlime(object)));
+            return Change.ApplicationChange.of(applicationVersionFromSlime(object));
         else
-            return Optional.of(Change.ApplicationChange.unknown());
+            return Change.ApplicationChange.unknown();
     }
 
     private List<JobStatus> jobStatusListFromSlime(Inspector array) {
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/restapi/application/ApplicationApiHandler.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/restapi/application/ApplicationApiHandler.java
index 5afd89846b6..00f1fe3790c 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/restapi/application/ApplicationApiHandler.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/restapi/application/ApplicationApiHandler.java
@@ -350,10 +350,10 @@ public class ApplicationApiHandler extends LoggingRequestHandler {
         // Currently deploying change
         if (application.deploying().isPresent()) {
             Cursor deployingObject = object.setObject("deploying");
-            if (application.deploying().get() instanceof Change.VersionChange)
-                deployingObject.setString("version", ((Change.VersionChange)application.deploying().get()).version().toString());
-            else if (((Change.ApplicationChange)application.deploying().get()).version() != ApplicationVersion.unknown)
-                toSlime(((Change.ApplicationChange)application.deploying().get()).version(), deployingObject.setObject("revision"));
+            if (application.deploying() instanceof Change.VersionChange)
+                deployingObject.setString("version", ((Change.VersionChange)application.deploying()).version().toString());
+            else if (((Change.ApplicationChange)application.deploying()).version() != ApplicationVersion.unknown)
+                toSlime(((Change.ApplicationChange)application.deploying()).version(), deployingObject.setObject("revision"));
         }
 
         // Jobs sorted according to deployment spec
@@ -713,7 +713,7 @@ public class ApplicationApiHandler extends LoggingRequestHandler {
         controller.applications().lockOrThrow(id, application -> {
             if (application.deploying().isPresent())
                 throw new IllegalArgumentException("Can not start a deployment of " + application + " at this time: " +
-                                                           application.deploying().get() + " is in progress");
+                                                           application.deploying() + " is in progress");
 
             controller.applications().deploymentTrigger().triggerChange(application.id(), new Change.VersionChange(version));
         });
@@ -724,14 +724,14 @@ public class ApplicationApiHandler extends LoggingRequestHandler {
     private HttpResponse cancelDeploy(String tenantName, String applicationName) {
         ApplicationId id = ApplicationId.from(tenantName, applicationName, "default");
         Application application = controller.applications().require(id);
-        Optional<Change> change = application.deploying();
+        Change change = application.deploying();
         if ( ! change.isPresent())
             return new MessageResponse("No deployment in progress for " + application + " at this time");
 
         controller.applications().lockOrThrow(id, lockedApplication ->
             controller.applications().deploymentTrigger().cancelChange(id));
 
-        return new MessageResponse("Cancelled " + change.get() + " for " + application);
+        return new MessageResponse("Cancelled " + change + " for " + application);
     }
 
     /** Schedule restart of deployment, or specific host in a deployment */
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/ControllerTest.java b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/ControllerTest.java
index 063ccc79fe5..3b4c3dda191 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/ControllerTest.java
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/ControllerTest.java
@@ -103,12 +103,12 @@ public class ControllerTest {
         tester.notifyJobCompletion(component, app1, true);
         assertEquals("Application version is currently not known",
                      ApplicationVersion.unknown,
-                     ((Change.ApplicationChange)tester.controller().applications().require(app1.id()).deploying().get()).version());
+                     ((Change.ApplicationChange)tester.controller().applications().require(app1.id()).deploying()).version());
         tester.deployAndNotify(app1, applicationPackage, true, systemTest);
         tester.deployAndNotify(app1, applicationPackage, true, stagingTest);
         assertEquals(4, applications.require(app1.id()).deploymentJobs().jobStatus().size());
 
-        ApplicationVersion applicationVersion = ((Change.ApplicationChange)tester.controller().applications().require(app1.id()).deploying().get()).version();
+        ApplicationVersion applicationVersion = ((Change.ApplicationChange)tester.controller().applications().require(app1.id()).deploying()).version();
         assertTrue("Application version has been set during deployment", applicationVersion != ApplicationVersion.unknown);
         assertStatus(JobStatus.initial(stagingTest)
                               .withTriggering(version1, applicationVersion, false, "", tester.clock().instant().minus(Duration.ofMillis(1)))
@@ -223,8 +223,7 @@ public class ControllerTest {
         ApplicationVersion expectedVersion = ApplicationVersion.from(source, 37);
         assertEquals(expectedVersionString, ((Change.ApplicationChange) tester.controller().applications()
                                                                               .require(app1.id())
-                                                                              .deploying()
-                                                                              .get()).version().id());
+                                                                              .deploying()).version().id());
 
         // Deploy without application package
         tester.deployAndNotify(app1, true, systemTest);
@@ -670,7 +669,7 @@ public class ControllerTest {
         Application app = tester.createApplication(tenant, "app1", "default", 1);
 
         tester.controller().applications().lockOrThrow(app.id(), application -> {
-            application = application.withDeploying(Optional.of(new Change.VersionChange(Version.fromString("6.3"))));
+            application = application.withDeploying(new Change.VersionChange(Version.fromString("6.3")));
             applications.store(application);
             try {
                 tester.deploy(app, ZoneId.from("prod", "us-east-3"));
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/deployment/DeploymentTester.java b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/deployment/DeploymentTester.java
index 8de32b4b531..247ec83aff2 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/deployment/DeploymentTester.java
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/deployment/DeploymentTester.java
@@ -18,8 +18,8 @@ import com.yahoo.vespa.hosted.controller.application.Change;
 import com.yahoo.vespa.hosted.controller.application.DeploymentJobs;
 import com.yahoo.vespa.hosted.controller.application.DeploymentJobs.JobType;
 import com.yahoo.vespa.hosted.controller.application.SourceRevision;
-import com.yahoo.vespa.hosted.controller.maintenance.ReadyJobsTrigger;
 import com.yahoo.vespa.hosted.controller.maintenance.JobControl;
+import com.yahoo.vespa.hosted.controller.maintenance.ReadyJobsTrigger;
 import com.yahoo.vespa.hosted.controller.maintenance.Upgrader;
 import com.yahoo.vespa.hosted.controller.versions.VersionStatus;
 
@@ -95,9 +95,9 @@ public class DeploymentTester {
     }
 
     public Optional<Change.VersionChange> versionChange(ApplicationId application) {
-        return application(application).deploying()
-                .filter(c -> c instanceof Change.VersionChange)
-                .map(Change.VersionChange.class::cast);
+        Change change = application(application).deploying();
+        if (change instanceof Change.VersionChange) return Optional.of((Change.VersionChange)change);
+        return Optional.empty();
     }
 
     public void updateVersionStatus() {
@@ -226,7 +226,7 @@ public class DeploymentTester {
 
     public void completeUpgrade(Application application, Version version, ApplicationPackage applicationPackage) {
         assertTrue(application + " has a deployment", applications().require(application.id()).deploying().isPresent());
-        assertEquals(new Change.VersionChange(version), applications().require(application.id()).deploying().get());
+        assertEquals(new Change.VersionChange(version), applications().require(application.id()).deploying());
         completeDeployment(application, applicationPackage, Optional.empty(), true);
     }
 
@@ -240,7 +240,7 @@ public class DeploymentTester {
 
     private void completeUpgradeWithError(Application application, Version version, ApplicationPackage applicationPackage, Optional<JobType> failOnJob) {
         assertTrue(applications().require(application.id()).deploying().isPresent());
-        assertEquals(new Change.VersionChange(version), applications().require(application.id()).deploying().get());
+        assertEquals(new Change.VersionChange(version), applications().require(application.id()).deploying());
         completeDeployment(application, applicationPackage, failOnJob, true);
     }
 
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/deployment/DeploymentTriggerTest.java b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/deployment/DeploymentTriggerTest.java
index 74d03240ec3..4bc64a8f213 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/deployment/DeploymentTriggerTest.java
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/deployment/DeploymentTriggerTest.java
@@ -13,13 +13,12 @@ import com.yahoo.vespa.hosted.controller.application.ApplicationPackage;
 import com.yahoo.vespa.hosted.controller.application.Change;
 import com.yahoo.vespa.hosted.controller.application.DeploymentJobs;
 import com.yahoo.vespa.hosted.controller.application.DeploymentJobs.JobType;
-import com.yahoo.vespa.hosted.controller.maintenance.ReadyJobsTrigger;
 import com.yahoo.vespa.hosted.controller.maintenance.JobControl;
+import com.yahoo.vespa.hosted.controller.maintenance.ReadyJobsTrigger;
 import org.junit.Test;
 
 import java.time.Duration;
 import java.time.Instant;
-import java.util.Optional;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -321,7 +320,7 @@ public class DeploymentTriggerTest {
                                                                  new JobControl(tester.controllerTester().curator()));
         LockedApplication app = (LockedApplication)tester.createAndDeploy("default0", 3, "default");
         // Store that we are upgrading but don't start the system-tests job
-        tester.controller().applications().store(app.withDeploying(Optional.of(new Change.VersionChange(Version.fromString("6.2")))));
+        tester.controller().applications().store(app.withDeploying(new Change.VersionChange(Version.fromString("6.2"))));
         assertEquals(0, tester.buildSystem().jobs().size());
         readyJobsTrigger.run();
         assertEquals(1, tester.buildSystem().jobs().size());
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/OutstandingChangeDeployerTest.java b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/OutstandingChangeDeployerTest.java
index 13636122cfd..d904e1f87c0 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/OutstandingChangeDeployerTest.java
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/OutstandingChangeDeployerTest.java
@@ -20,28 +20,28 @@ import static org.junit.Assert.assertTrue;
  * @author bratseth
  */
 public class OutstandingChangeDeployerTest {
-    
+
     @Test
     public void testChangeDeployer() {
         DeploymentTester tester = new DeploymentTester();
         tester.configServer().setDefaultVersion(new Version(6, 1));
-        OutstandingChangeDeployer deployer = new OutstandingChangeDeployer(tester.controller(), Duration.ofMinutes(10), 
+        OutstandingChangeDeployer deployer = new OutstandingChangeDeployer(tester.controller(), Duration.ofMinutes(10),
                                                                            new JobControl(new MockCuratorDb()));
         tester.createAndDeploy("app1", 11, "default");
         tester.createAndDeploy("app2", 22, "default");
 
         Version version = new Version(6, 2);
         tester.deploymentTrigger().triggerChange(tester.application("app1").id(), new Change.VersionChange(version));
-        
-        assertEquals(new Change.VersionChange(version), tester.application("app1").deploying().get());
+
+        assertEquals(new Change.VersionChange(version), tester.application("app1").deploying());
         assertFalse(tester.application("app1").hasOutstandingChange());
         tester.notifyJobCompletion(DeploymentJobs.JobType.component, tester.application("app1"), true);
         assertTrue(tester.application("app1").hasOutstandingChange());
         assertEquals(1, tester.buildSystem().jobs().size());
-        
+
         deployer.maintain();
         assertEquals("No effect as job is in progress", 1, tester.buildSystem().jobs().size());
-        
+
         tester.deployCompletely("app1");
         assertEquals("Upgrade done", 0, tester.buildSystem().jobs().size());
 
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/UpgraderTest.java b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/UpgraderTest.java
index fd13b99f25e..63043d39b55 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/UpgraderTest.java
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/UpgraderTest.java
@@ -174,11 +174,11 @@ public class UpgraderTest {
         assertEquals(VespaVersion.Confidence.normal, tester.controller().versionStatus().systemVersion().get().confidence());
         tester.upgrader().maintain();
         assertEquals("Upgrade of defaults are scheduled", 5, tester.buildSystem().jobs().size());
-        assertEquals(version54, ((Change.VersionChange)tester.application(default0.id()).deploying().get()).version());
-        assertEquals(version54, ((Change.VersionChange)tester.application(default1.id()).deploying().get()).version());
-        assertEquals(version54, ((Change.VersionChange)tester.application(default2.id()).deploying().get()).version());
-        assertEquals(version54, ((Change.VersionChange)tester.application(default3.id()).deploying().get()).version());
-        assertEquals(version54, ((Change.VersionChange)tester.application(default4.id()).deploying().get()).version());
+        assertEquals(version54, ((Change.VersionChange)tester.application(default0.id()).deploying()).version());
+        assertEquals(version54, ((Change.VersionChange)tester.application(default1.id()).deploying()).version());
+        assertEquals(version54, ((Change.VersionChange)tester.application(default2.id()).deploying()).version());
+        assertEquals(version54, ((Change.VersionChange)tester.application(default3.id()).deploying()).version());
+        assertEquals(version54, ((Change.VersionChange)tester.application(default4.id()).deploying()).version());
         tester.completeUpgrade(default0, version54, "default");
         // State: Default applications started upgrading to 5.4 (and one completed)
         Version version55 = Version.fromString("5.5");
@@ -190,11 +190,11 @@ public class UpgraderTest {
         assertEquals(VespaVersion.Confidence.normal, tester.controller().versionStatus().systemVersion().get().confidence());
         tester.upgrader().maintain();
         assertEquals("Upgrade of defaults are scheduled", 5, tester.buildSystem().jobs().size());
-        assertEquals(version55, ((Change.VersionChange)tester.application(default0.id()).deploying().get()).version());
-        assertEquals(version54, ((Change.VersionChange)tester.application(default1.id()).deploying().get()).version());
-        assertEquals(version54, ((Change.VersionChange)tester.application(default2.id()).deploying().get()).version());
-        assertEquals(version54, ((Change.VersionChange)tester.application(default3.id()).deploying().get()).version());
-        assertEquals(version54, ((Change.VersionChange)tester.application(default4.id()).deploying().get()).version());
+        assertEquals(version55, ((Change.VersionChange)tester.application(default0.id()).deploying()).version());
+        assertEquals(version54, ((Change.VersionChange)tester.application(default1.id()).deploying()).version());
+        assertEquals(version54, ((Change.VersionChange)tester.application(default2.id()).deploying()).version());
+        assertEquals(version54, ((Change.VersionChange)tester.application(default3.id()).deploying()).version());
+        assertEquals(version54, ((Change.VersionChange)tester.application(default4.id()).deploying()).version());
         tester.completeUpgrade(default1, version54, "default");
         tester.completeUpgrade(default2, version54, "default");
         tester.completeUpgradeWithError(default3, version54, "default", DeploymentJobs.JobType.stagingTest);
@@ -216,7 +216,7 @@ public class UpgraderTest {
         assertEquals("Upgrade of defaults are scheduled on 5.4 instead, since 5.5 broken: " +
                      "This is default3 since it failed upgrade on both 5.4 and 5.5",
                      1, tester.buildSystem().jobs().size());
-        assertEquals("5.4", ((Change.VersionChange)tester.application(default3.id()).deploying().get()).version().toString());
+        assertEquals("5.4", ((Change.VersionChange)tester.application(default3.id()).deploying()).version().toString());
     }
 
     @Test
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/persistence/ApplicationSerializerTest.java b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/persistence/ApplicationSerializerTest.java
index 1e00ecc2107..f674e7be02e 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/persistence/ApplicationSerializerTest.java
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/persistence/ApplicationSerializerTest.java
@@ -82,7 +82,7 @@ public class ApplicationSerializerTest {
                                                deploymentSpec,
                                                validationOverrides,
                                                deployments, deploymentJobs,
-                                               Optional.of(new Change.VersionChange(Version.fromString("6.7"))),
+                                               new Change.VersionChange(Version.fromString("6.7")),
                                                true,
                                                Optional.of(IssueId.from("1234")),
                                                new MetricsService.ApplicationMetrics(0.5, 0.9),
@@ -145,22 +145,20 @@ public class ApplicationSerializerTest {
         assertEquals(6, serialized.deployments().get(zone2).metrics().writeLatencyMillis(), Double.MIN_VALUE);
 
         { // test more deployment serialization cases
-            Application original2 = writable(original).withDeploying(Optional.of(Change.ApplicationChange.of(ApplicationVersion
-                                                                                                                     .from("hash1"))));
+            Application original2 = writable(original).withDeploying(Change.ApplicationChange.of(ApplicationVersion.from("hash1")));
             Application serialized2 = applicationSerializer.fromSlime(applicationSerializer.toSlime(original2));
             assertEquals(original2.deploying(), serialized2.deploying());
-            assertEquals(((Change.ApplicationChange)serialized2.deploying().get()).version().source(),
-                         ((Change.ApplicationChange)original2.deploying().get()).version().source());
+            assertEquals(((Change.ApplicationChange)serialized2.deploying()).version().source(),
+                         ((Change.ApplicationChange)original2.deploying()).version().source());
 
-            Application original3 = writable(original).withDeploying(Optional.of(Change.ApplicationChange.of(ApplicationVersion
-                                                                                                                     .from("hash1",
-                                                                                                                           new SourceRevision("a", "b", "c")))));
+            Application original3 = writable(original).withDeploying(Change.ApplicationChange.of(ApplicationVersion.from("hash1",
+                                                                                                                         new SourceRevision("a", "b", "c"))));
             Application serialized3 = applicationSerializer.fromSlime(applicationSerializer.toSlime(original3));
             assertEquals(original3.deploying(), serialized2.deploying());
-            assertEquals(((Change.ApplicationChange)serialized3.deploying().get()).version().source(),
-                         ((Change.ApplicationChange)original3.deploying().get()).version().source());
+            assertEquals(((Change.ApplicationChange)serialized3.deploying()).version().source(),
+                         ((Change.ApplicationChange)original3.deploying()).version().source());
 
-            Application original4 = writable(original).withDeploying(Optional.empty());
+            Application original4 = writable(original).withDeploying(Change.empty());
             Application serialized4 = applicationSerializer.fromSlime(applicationSerializer.toSlime(original4));
             assertEquals(original4.deploying(), serialized4.deploying());
         }