Use BigDecimal for budget inside the Quota

- To allow budgets below $1/hour we change the internal representation of budget
  to a decimal number.  Some interfaces that assume integers are kept to keep the
  API stable.

- Created a nicer method .unlimited() instead of .empt() to better show semantics.

- Added some serialisation tests to make sure we support integers and decimals.

3 files changed, 8 insertions, 6 deletions

diff --git a/config-model/src/main/java/com/yahoo/config/model/deploy/TestProperties.java b/config-model/src/main/java/com/yahoo/config/model/deploy/TestProperties.java
index 31c72e1be69..1455b4d8007 100644
--- a/config-model/src/main/java/com/yahoo/config/model/deploy/TestProperties.java
+++ b/config-model/src/main/java/com/yahoo/config/model/deploy/TestProperties.java
@@ -51,7 +51,7 @@ public class TestProperties implements ModelContext.Properties {
     private Optional<EndpointCertificateSecrets> endpointCertificateSecrets = Optional.empty();
     private AthenzDomain athenzDomain;
     private ApplicationRoles applicationRoles;
-    private Quota quota = Quota.empty();
+    private Quota quota = Quota.unlimited();
 
     @Override public boolean multitenant() { return multitenant; }
     @Override public ApplicationId applicationId() { return applicationId; }
diff --git a/config-model/src/main/java/com/yahoo/vespa/model/application/validation/QuotaValidator.java b/config-model/src/main/java/com/yahoo/vespa/model/application/validation/QuotaValidator.java
index c0a2fe4fdf2..d06d616efac 100644
--- a/config-model/src/main/java/com/yahoo/vespa/model/application/validation/QuotaValidator.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/application/validation/QuotaValidator.java
@@ -6,6 +6,7 @@ import com.yahoo.config.provision.Capacity;
 import com.yahoo.config.provision.ClusterSpec;
 import com.yahoo.vespa.model.VespaModel;
 
+import java.math.BigDecimal;
 import java.util.Locale;
 import java.util.stream.Collectors;
 
@@ -19,17 +20,17 @@ public class QuotaValidator extends Validator {
     public void validate(VespaModel model, DeployState deployState) {
         var quota = deployState.getProperties().quota();
         quota.maxClusterSize().ifPresent(maxClusterSize -> validateMaxClusterSize(maxClusterSize, model));
-        quota.budget().ifPresent(budget -> validateBudget(budget, model));
+        quota.budgetAsDecimal().ifPresent(budget -> validateBudget(budget, model));
     }
 
-    private void validateBudget(int budget, VespaModel model) {
+    private void validateBudget(BigDecimal budget, VespaModel model) {
         var spend = model.allClusters().stream()
                 .map(clusterId -> model.provisioned().all().get(clusterId))
                 .map(Capacity::maxResources)
                 .map(clusterCapacity -> clusterCapacity.nodeResources().cost() * clusterCapacity.nodes())
                 .reduce(0.0, Double::sum);
 
-        if (spend > budget) {
+        if (budget.doubleValue() < spend) {
             throwBudgetExceeded(spend, budget);
         }
     }
@@ -51,7 +52,7 @@ public class QuotaValidator extends Validator {
         }
     }
 
-    private void throwBudgetExceeded(double spend, double budget) {
+    private void throwBudgetExceeded(double spend, BigDecimal budget) {
         var message = String.format(Locale.US, "Hourly spend for maximum specified resources ($%.2f) exceeds budget from quota ($%.2f)!", spend, budget);
         throw new IllegalArgumentException(message);
     }
diff --git a/config-model/src/test/java/com/yahoo/vespa/model/application/validation/QuotaValidatorTest.java b/config-model/src/test/java/com/yahoo/vespa/model/application/validation/QuotaValidatorTest.java
index 10199bfe6b9..70a6bbbf659 100644
--- a/config-model/src/test/java/com/yahoo/vespa/model/application/validation/QuotaValidatorTest.java
+++ b/config-model/src/test/java/com/yahoo/vespa/model/application/validation/QuotaValidatorTest.java
@@ -6,6 +6,7 @@ import com.yahoo.config.model.deploy.TestProperties;
 import com.yahoo.config.provision.Environment;
 import org.junit.Test;
 
+import java.math.BigDecimal;
 import java.util.Optional;
 
 import static org.junit.Assert.assertEquals;
@@ -16,7 +17,7 @@ import static org.junit.Assert.fail;
  */
 public class QuotaValidatorTest {
 
-    private final Quota quota = new Quota(Optional.of(10), Optional.of(1));
+    private final Quota quota = Quota.unlimited().withClusterSize(Optional.of(10)).withBudget(Optional.of(BigDecimal.valueOf(1)));
 
     @Test
     public void test_deploy_under_quota() {