[DO NOT MERGE] skeleton myst shard discovery

meta-grpc-client/src/main/java/net/opentsdb/aura/metrics/meta/endpoints/ShardEndPoint.java

@@ -0,0 +1,16 @@
+package net.opentsdb.aura.metrics.meta.endpoints;
+
+public interface ShardEndPoint {
+
+    String getHost();
+
+    int getPort();
+
+    Protocol getProtocol();
+
+    boolean mtls();
+
+    enum Protocol {
+        http1_1, http2_0, https1_1, https_2_0
+    }
+}

meta-grpc-client/src/main/java/net/opentsdb/aura/metrics/meta/endpoints/ShardedServiceRegistry.java

@@ -0,0 +1,11 @@
+package net.opentsdb.aura.metrics.meta.endpoints;
+
+import java.util.List;
+import java.util.Map;
+
+public interface ShardedServiceRegistry {
+
+    Map<String, List<ShardEndPoint>> getEndpoints(String namespace);
+
+    Map<String, List<ShardEndPoint>> getEndpoints(String namespace, long epoch);
+}

meta-grpc-client/src/main/java/net/opentsdb/aura/metrics/meta/endpoints/impl/KubernetesStatefulRegistry.java

@@ -0,0 +1,41 @@
+package net.opentsdb.aura.metrics.meta.endpoints.impl;
+
+import net.opentsdb.aura.metrics.meta.endpoints.ShardedServiceRegistry;
+
+//TODO:
+// Parse the yaml file.
+// Look at Plugin implementation.
+// if it is too complicated, then parse the file yourself.
+// Parsing the file should use ObjectMapper.
+public abstract class KubernetesStatefulRegistry implements ShardedServiceRegistry {
+
+    private String type;
+    private final String[] replicas = {"a", "b", "c", "d", "e"};
+    protected static final String NUM_SHARDS = "num-shards";
+    protected static final String REPLICAS = "replicas";
+    protected static final String K8S_NAMESPACE = "k8s_namespace";
+
+    public KubernetesStatefulRegistry(final String type) {
+        this.type = type;
+    }
+
+    protected int getNumShards(String namespace) {
+        return 0;
+    }
+
+    protected int getNumReplicas(String namespace) {
+        return 0;
+    }
+
+    protected String getReplica(int replicaId) {
+        return replicas[replicaId];
+    }
+
+    protected int getPort(String namespace) {
+        return 0;
+    }
+
+    protected String getDomain(String namespace) {
+        return null;
+    }
+}

meta-grpc-client/src/main/java/net/opentsdb/aura/metrics/meta/endpoints/impl/MystEndpoint.java

@@ -0,0 +1,59 @@
+package net.opentsdb.aura.metrics.meta.endpoints.impl;
+
+import net.opentsdb.aura.metrics.meta.endpoints.ShardEndPoint;
+//TODO: Make a builder
+public class MystEndpoint implements ShardEndPoint {
+
+    private final String host;
+    private final int port;
+
+    public MystEndpoint(String host, int port) {
+        this.host = host;
+        this.port = port;
+    }
+
+
+    @Override
+    public String getHost() {
+        return this.host;
+    }
+
+    @Override
+    public int getPort() {
+        return this.port;
+    }
+
+    @Override
+    public Protocol getProtocol() {
+        return Protocol.http2_0;
+    }
+
+    @Override
+    public boolean mtls() {
+        return false;
+    }
+
+    public static class Builder {
+        private String l_host;
+        private int l_port;
+
+        public Builder withHost(String host) {
+            this.l_host = host;
+            return this;
+        }
+
+        public Builder withPort(int port) {
+            this.l_port = port;
+            return this;
+        }
+
+        public MystEndpoint build() {
+            return new MystEndpoint(l_host, l_port);
+        }
+
+        public static Builder newBuilder() {
+            return new Builder();
+        }
+
+    }
+}

meta-grpc-client/src/main/java/net/opentsdb/aura/metrics/meta/endpoints/impl/MystStatefulSetRegistry.java

@@ -0,0 +1,52 @@
+package net.opentsdb.aura.metrics.meta.endpoints.impl;
+
+import net.opentsdb.aura.metrics.meta.endpoints.ShardEndPoint;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+//TODO:
+// make a cache
+// Refetch for a namespace only if things have changed
+// Write testcases using Mocks (jmockit or mockito)
+public class MystStatefulSetRegistry extends KubernetesStatefulRegistry {
+
+    private static final String pod_name_pattern = "%s-myst-%s-%s.svc.%s";
+
+    public MystStatefulSetRegistry() {
+        super("myst");
+    }
+
+    @Override
+    public Map<String, List<ShardEndPoint>> getEndpoints(String namespace) {
+        Map<String, List<ShardEndPoint>> endpointsMap = new HashMap<>();
+
+        final int numShards = getNumShards(namespace);
+        final int numReplicas = getNumReplicas(namespace);
+        for(int i = 0; i < numReplicas; i++) {
+            String replica = getReplica(i);
+            List<ShardEndPoint> shardEndPoints = new ArrayList<>();
+            endpointsMap.put(replica, shardEndPoints);
+            for (int j = 0; j < numShards; i++) {
+                final MystEndpoint endpoint = MystEndpoint.Builder.newBuilder()
+                        .withHost(
+                                String.format(
+                                        pod_name_pattern,
+                                        namespace,
+                                        replica,
+                                        j,
+                                        getDomain(namespace)))
+                        .withPort(getPort(namespace))
+                        .build();
+                shardEndPoints.add(endpoint);
+            }
+        }
+        return endpointsMap;
+    }
+
+    @Override
+    public Map<String, List<ShardEndPoint>> getEndpoints(String namespace, long epoch) {
+        return getEndpoints(namespace);
+    }
+}