[Kayrock] Add describe consumer groups endpoint as kayrock

.github/workflows/test.yml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   setup:
-    name: test / setup
+    name: test | setup dependencies
     runs-on: ubuntu-20.04
     env:
       MIX_ENV: test

docker-compose-arm.yml

@@ -0,0 +1,94 @@
+version: '3.9'
+
+services:
+  zookeeper:
+    image: confluentinc/cp-zookeeper:7.0.4.arm64
+    restart: unless-stopped
+    ports:
+      - '32181:32181'
+    environment:
+      ZOOKEEPER_CLIENT_PORT: 32181
+      ZOOKEEPER_TICK_TIME: 2000
+    healthcheck:
+      test: "zookeeper-shell 127.0.01:32181 ls /"
+      interval: 10s
+      timeout: 10s
+      retries: 5
+
+  kafka-1:
+    image: confluentinc/cp-kafka:7.0.4.arm64
+    ports:
+      - '9092:9092'
+    depends_on:
+      zookeeper:
+        condition: service_healthy
+    env_file: docker-compose-kafka.env
+    environment:
+      KAFKA_BROKER_ID: 1
+      KAFKA_ZOOKEEPER_CONNECT: zookeeper:32181
+      KAFKA_ADVERTISED_LISTENERS: INTERNAL://kafka-1:29092,EXTERNAL://localhost:9092
+    healthcheck:
+      test: kafka-topics --bootstrap-server kafka-1:29092 --list
+      interval: 30s
+      timeout: 10s
+      retries: 4
+    volumes:
+      - ./ssl/kafka.server.keystore.jks:/etc/kafka/secrets/kafka.server.keystore.jks:ro,z
+      - ./ssl/kafka.server.truststore.jks:/etc/kafka/secrets/kafka.server.truststore.jks:ro,z
+
+  kafka-2:
+    image: confluentinc/cp-kafka:7.0.4.arm64
+    ports:
+      - '9093:9093'
+    depends_on:
+      zookeeper:
+        condition: service_healthy
+    env_file: docker-compose-kafka.env
+    environment:
+      KAFKA_BROKER_ID: 2
+      KAFKA_ZOOKEEPER_CONNECT: zookeeper:32181
+      KAFKA_ADVERTISED_LISTENERS: INTERNAL://kafka-2:29093,EXTERNAL://localhost:9093
+    healthcheck:
+      test: kafka-topics --bootstrap-server kafka-2:29093 --list
+      interval: 30s
+      timeout: 10s
+      retries: 4
+    volumes:
+      - ./ssl/kafka.server.keystore.jks:/etc/kafka/secrets/kafka.server.keystore.jks:ro,z
+      - ./ssl/kafka.server.truststore.jks:/etc/kafka/secrets/kafka.server.truststore.jks:ro,z
+
+  kafka-3:
+    image: confluentinc/cp-kafka:7.0.4.arm64
+    ports:
+      - '9094:9094'
+    depends_on:
+      zookeeper:
+        condition: service_healthy
+    env_file: docker-compose-kafka.env
+    environment:
+      KAFKA_BROKER_ID: 3
+      KAFKA_ZOOKEEPER_CONNECT: zookeeper:32181
+      KAFKA_ADVERTISED_LISTENERS: INTERNAL://kafka-3:29094,EXTERNAL://localhost:9094
+    healthcheck:
+      test: kafka-topics --bootstrap-server kafka-2:29093 --list
+      interval: 30s
+      timeout: 10s
+      retries: 4
+    volumes:
+      - ./ssl/kafka.server.keystore.jks:/etc/kafka/secrets/kafka.server.keystore.jks:ro,z
+      - ./ssl/kafka.server.truststore.jks:/etc/kafka/secrets/kafka.server.truststore.jks:ro,z
+
+  kafka_setup:
+    image: confluentinc/cp-kafka:7.0.4.arm64
+    depends_on:
+      zookeeper:
+        condition: service_healthy
+      kafka-1:
+        condition: service_healthy
+      kafka-2:
+        condition: service_healthy
+      kafka-3:
+        condition: service_healthy
+    command: "bash -c 'kafka-topics --zookeeper zookeeper:32181 --create --if-not-exists --partitions 4 --replication-factor 2 --topic consumer_group_implementation_test && \
+                       kafka-topics --zookeeper zookeeper:32181 --create --if-not-exists --partitions 4 --replication-factor 2 --topic test0p8p0 && \
+                       kafka-topics --zookeeper zookeeper:32181 --list'"

lib/kafka_ex.ex

@@ -123,6 +123,22 @@
     Server.call(worker, :consumer_group)
   end
 
+  @doc """
+  Sends a request to describe a group identified by its name.
+  We support only one consumer group per request for now, as we don't
+  group requests by group coordinator.
+  This is a new client implementation, and is not compatible with the old clients
+  """
+  @spec describe_group(binary, Keyword.t()) :: {:ok, any} | {:error, any}
+  def describe_group(consumer_group_name, opts \\ []) do
+    worker_name = Keyword.get(opts, :worker_name, Config.default_worker())
+
+    case Server.call(worker_name, {:describe_groups, [consumer_group_name]}) do
+      {:ok, [group]} -> {:ok, group}
+      {:error, error} -> {:error, error}
+    end
+  end
+
   @doc """
   Sends a request to join a consumer group.
   """
@@ -643,7 +659,7 @@
     end
   end
 
   defp current_offset(
          supplied_offset,
          partition,
          topic,

lib/kafka_ex/new/client.ex

@@ -14,6 +14,8 @@ defmodule KafkaEx.New.Client do
   alias KafkaEx.Config
   alias KafkaEx.NetworkClient
 
+  alias KafkaEx.New.Client.RequestBuilder
+  alias KafkaEx.New.Client.ResponseParser
   alias KafkaEx.New.Structs.Broker
   alias KafkaEx.New.Structs.ClusterMetadata
   alias KafkaEx.New.Structs.NodeSelector
@@ -163,6 +165,16 @@ defmodule KafkaEx.New.Client do
     {:reply, {:ok, topic_metadata}, updated_state}
   end
 
+  def handle_call({:describe_groups, [consumer_group_name]}, _from, state) do
+    if KafkaEx.valid_consumer_group?(consumer_group_name) do
+      {response, updated_state} = describe_group_request(consumer_group_name, state)
+
+      {:reply, response, updated_state}
+    else
+      {:reply, {:error, :invalid_consumer_group}, state}
+    end
+  end
+
   def handle_call({:kayrock_request, request, node_selector}, _from, state) do
     {response, updated_state} = kayrock_network_request(request, node_selector, state)
 
@@ -245,6 +257,66 @@ defmodule KafkaEx.New.Client do
     end
   end
 
+  defp describe_group_request(consumer_group_name, state) do
+    node_selector = NodeSelector.consumer_group(consumer_group_name)
+
+    [consumer_group_name]
+    |> RequestBuilder.describe_groups_request(state)
+    |> handle_describe_group_request(node_selector, state)
+  end
+
+  defp handle_describe_group_request(
+         _,
+         _,
+         _,
+         retry_count \\ @retry_count,
+         _last_error \\ nil
+       )
+
+  defp handle_describe_group_request(_, _, state, 0, last_error) do
+    {{:error, last_error}, state}
+  end
+
+  defp handle_describe_group_request(
+         request,
+         node_selector,
+         state,
+         retry_count,
+         _last_error
+       ) do
+    case kayrock_network_request(request, node_selector, state) do
+      {{:ok, response}, state_out} ->
+        case ResponseParser.describe_groups_response(response) do
+          {:ok, consumer_groups} ->
+            {{:ok, consumer_groups}, state_out}
+
+          {:error, [error | _]} ->
+            Logger.warn(
+              "Unable to fetch consumer group metadata for #{inspect(request.group_ids)}"
+            )
+
+            handle_describe_group_request(
+              request,
+              node_selector,
+              state,
+              retry_count - 1,
+              error
+            )
+        end
+
+      {_, _state_out} ->
+        Logger.warn("Unable to fetch consumer group metadata for #{inspect(request.group_ids)}")
+
+        handle_describe_group_request(
+          request,
+          node_selector,
+          state,
+          retry_count - 1,
+          :unknown
+        )
+    end
+  end
+
   defp maybe_connect_broker(broker, state) do
     case Broker.connected?(broker) do
       true ->

lib/kafka_ex/new/client/request_builder.ex

@@ -0,0 +1,34 @@
+defmodule KafkaEx.New.Client.RequestBuilder do
+  @moduledoc """
+  This module is used to build request for KafkaEx.New.Client.
+  It's main decision point which protocol to use for building request and what
+  is required version.
+  """
+  @protocol Application.compile_env(
+              :kafka_ex,
+              :protocol,
+              KafkaEx.New.Protocols.KayrockProtocol
+            )
+
+  @default_api_version %{
+    describe_groups: 1
+  }
+
+  alias KafkaEx.New.Client.State
+
+  @doc """
+  Builds request for Describe Groups API
+  """
+  @spec describe_groups_request([binary], State.t()) :: term
+  def describe_groups_request(group_names, state) do
+    api_version = get_api_version(state, :describe_groups)
+
+    @protocol.build_request(:describe_groups, api_version, group_names: group_names)
+  end
+
+  # -----------------------------------------------------------------------------
+  defp get_api_version(state, request_type) do
+    default = Map.fetch!(@default_api_version, request_type)
+    State.max_supported_api_version(state, request_type, default)
+  end
+end

lib/kafka_ex/new/client/response_parser.ex

@@ -0,0 +1,22 @@
+defmodule KafkaEx.New.Client.ResponseParser do
+  @moduledoc """
+  This module is used to parse response from KafkaEx.New.Client.
+  It's main decision point which protocol to use for parsing response
+  """
+  alias KafkaEx.New.Structs.ConsumerGroup
+
+  @protocol Application.compile_env(
+              :kafka_ex,
+              :protocol,
+              KafkaEx.New.Protocols.KayrockProtocol
+            )
+
+  @doc """
+  Parses response for Describe Groups API
+  """
+  @spec describe_groups_response(term) ::
+          {:ok, [ConsumerGroup.t()]} | {:error, term}
+  def describe_groups_response(response) do
+    @protocol.parse_response(:describe_groups, response)
+  end
+end

lib/kafka_ex/new/kafka_ex_api.ex

@@ -15,6 +15,7 @@ defmodule KafkaEx.New.KafkaExAPI do
 
   alias KafkaEx.New.Client
   alias KafkaEx.New.Structs.ClusterMetadata
+  alias KafkaEx.New.Structs.ConsumerGroup
   alias KafkaEx.New.Structs.Topic
   alias KafkaEx.New.Structs.NodeSelector
 
@@ -56,6 +57,20 @@ defmodule KafkaEx.New.KafkaExAPI do
     end
   end
 
+  @doc """
+  Sends a request to describe a group identified by its name.
+  We support only one consumer group per request for now, as we don't
+  group requests by group coordinator.
+  """
+  @spec describe_group(client, Keyword.t()) ::
+          {:ok, ConsumerGroup.t()} | {:error, any}
+  def describe_group(client, consumer_group_name) do
+    case GenServer.call(client, {:describe_groups, [consumer_group_name]}) do
+      {:ok, [group]} -> {:ok, group}
+      {:error, error} -> {:error, error}
+    end
+  end
+
   @doc """
   Get topic metadata for the given topics
 
@@ -73,7 +88,7 @@ defmodule KafkaEx.New.KafkaExAPI do
   Returns the cluster metadata from the given client
   """
   @spec cluster_metadata(client) :: {:ok, ClusterMetadata.t()}
-  def(cluster_metadata(client)) do
+  def cluster_metadata(client) do
     GenServer.call(client, :cluster_metadata)
   end
 

lib/kafka_ex/new/protocols/kayrock/describe_groups.ex

@@ -0,0 +1,25 @@
+defprotocol KafkaEx.New.Protocols.Kayrock.DescribeGroups do
+  @moduledoc """
+  This module handles Describe Groups request & response parsing.
+  Request is built using Kayrock protocol, response is parsed to
+  native KafkaEx structs.
+  """
+
+  defprotocol Request do
+    @moduledoc """
+    This protocol is used to build Describe Groups request
+    """
+    @spec build_request(t(), [binary]) :: t()
+    def build_request(request, consumer_group_names)
+  end
+
+  defprotocol Response do
+    @moduledoc """
+    This protocol is used to parse Describe Groups response
+    """
+    alias KafkaEx.New.Structs.ConsumerGroup
+
+    @spec parse_response(t()) :: {:ok, [ConsumerGroup.t()]} | {:error, term}
+    def parse_response(response)
+  end
+end

lib/kafka_ex/new/protocols/kayrock/describe_groups/default_request_impl.ex

@@ -0,0 +1,6 @@
+defimpl KafkaEx.New.Protocols.Kayrock.DescribeGroups.Request,
+  for: [Kayrock.DescribeGroups.V0.Request, Kayrock.DescribeGroups.V1.Request] do
+  def build_request(request_template, consumer_group_names) do
+    Map.put(request_template, :group_ids, consumer_group_names)
+  end
+end

lib/kafka_ex/new/protocols/kayrock/describe_groups/default_response_impl.ex

@@ -0,0 +1,22 @@
+defimpl KafkaEx.New.Protocols.Kayrock.DescribeGroups.Response,
+  for: [Kayrock.DescribeGroups.V0.Response, Kayrock.DescribeGroups.V1.Response] do
+  def parse_response(%{groups: groups}) do
+    case Enum.filter(groups, &(&1.error_code != 0)) do
+      [] ->
+        groups = Enum.map(groups, &build_consumer_group/1)
+        {:ok, groups}
+
+      errors ->
+        error_list =
+          Enum.map(errors, fn %{group_id: group_id, error_code: error_code} ->
+            {group_id, Kayrock.ErrorCode.code_to_atom!(error_code)}
+          end)
+
+        {:error, error_list}
+    end
+  end
+
+  defp build_consumer_group(kayrock_group) do
+    KafkaEx.New.Structs.ConsumerGroup.from_describe_group_response(kayrock_group)
+  end
+end