Add weighted alias type

3 files changed, 109 insertions, 1 deletions

diff --git a/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/dns/AliasTarget.java b/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/dns/AliasTarget.java
index a5436bc3fc1..41723dbdea6 100644
--- a/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/dns/AliasTarget.java
+++ b/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/dns/AliasTarget.java
@@ -57,7 +57,12 @@ public abstract class AliasTarget {
 
     /** Unpack target from given record data */
     public static AliasTarget unpack(RecordData data) {
-        return LatencyAliasTarget.unpack(data);
+        String[] parts = data.asString().split("/");
+        switch (parts[0]) {
+            case "latency": return LatencyAliasTarget.unpack(data);
+            case "weighted": return WeightedAliasTarget.unpack(data);
+        }
+        throw new IllegalArgumentException("Unknown alias type '" + parts[0] + "'");
     }
 
 }
diff --git a/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/dns/WeightedAliasTarget.java b/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/dns/WeightedAliasTarget.java
new file mode 100644
index 00000000000..9d741cb2dbc
--- /dev/null
+++ b/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/dns/WeightedAliasTarget.java
@@ -0,0 +1,64 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.hosted.controller.api.integration.dns;
+
+import com.yahoo.config.provision.HostName;
+import com.yahoo.config.provision.zone.ZoneId;
+
+import java.util.Objects;
+
+/**
+ * An implementation of {@link AliasTarget} where is requests are answered based on the weight assigned to the
+ * record, as a proportion of the total weight for all records having the same DNS name.
+ *
+ * The portion of received traffic is calculated as follows: (record weight / sum of the weights of all records).
+ *
+ * @author mpolden
+ */
+public class WeightedAliasTarget extends AliasTarget {
+
+    private final long weight;
+
+    public WeightedAliasTarget(HostName name, String dnsZone, ZoneId zone, long weight) {
+        super(name, dnsZone, zone.value());
+        this.weight = weight;
+    }
+
+    /** The weight of this target */
+    public long weight() {
+        return weight;
+    }
+
+    @Override
+    public RecordData pack() {
+        return RecordData.from("weighted/" + name().value() + "/" + dnsZone() + "/" + id() + "/" + weight);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        if (!super.equals(o)) return false;
+        WeightedAliasTarget that = (WeightedAliasTarget) o;
+        return weight == that.weight;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(super.hashCode(), weight);
+    }
+
+    /** Unpack weighted alias from given record data */
+    public static WeightedAliasTarget unpack(RecordData data) {
+        var parts = data.asString().split("/");
+        if (parts.length != 5) {
+            throw new IllegalArgumentException("Expected data to be on format type/name/DNS-zone/zone-id/weight, " +
+                                               "but got " + data.asString());
+        }
+        if (!"weighted".equals(parts[0])) {
+            throw new IllegalArgumentException("Unexpected type '" + parts[0] + "'");
+        }
+        return new WeightedAliasTarget(HostName.from(parts[1]), parts[2], ZoneId.from(parts[3]),
+                                       Long.parseLong(parts[4]));
+    }
+
+}
diff --git a/controller-api/src/test/java/com/yahoo/vespa/hosted/controller/api/integration/dns/AliasTargetTest.java b/controller-api/src/test/java/com/yahoo/vespa/hosted/controller/api/integration/dns/AliasTargetTest.java
new file mode 100644
index 00000000000..7169222fe26
--- /dev/null
+++ b/controller-api/src/test/java/com/yahoo/vespa/hosted/controller/api/integration/dns/AliasTargetTest.java
@@ -0,0 +1,39 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.hosted.controller.api.integration.dns;
+
+import com.yahoo.config.provision.HostName;
+import com.yahoo.config.provision.zone.ZoneId;
+import org.junit.Test;
+
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+/**
+ * @author mpolden
+ */
+public class AliasTargetTest {
+
+    @Test
+    public void packing() {
+        List<AliasTarget> tests = List.of(
+                new LatencyAliasTarget(HostName.from("foo.example.com"), "dns-zone-1", ZoneId.from("prod.us-north-1")),
+                new WeightedAliasTarget(HostName.from("bar.example.com"), "dns-zone-2", ZoneId.from("prod.us-north-2"), 50)
+        );
+        for (var target : tests) {
+            AliasTarget unpacked = AliasTarget.unpack(target.pack());
+            assertEquals(target, unpacked);
+        }
+
+        List<RecordData> invalidData = List.of(RecordData.from(""), RecordData.from("foobar"));
+        for (var data : invalidData) {
+            try {
+                AliasTarget.unpack(data);
+                fail("Expected exception");
+            } catch (IllegalArgumentException ignored) {
+            }
+        }
+    }
+
+}