Update docs to include configurable interval

.tool-versions

@@ -1,4 +1,2 @@
 elixir 1.16.2-otp-26
 erlang 26.0.2
-tilt 0.33.11
-kind 0.22.0

README.md

@@ -24,12 +24,21 @@ partition for this group.
 ## Start
 
 ```bash
-docker run -ti --net="host" -e KAFKA_BROKERS=localhost:9093,localhost:9094,localhost:9095 -p 4000:4000 \
-  lechindianer/kafkaex_lag_exporter:0.2.0
+docker run -ti --net="host" -e KAFKA_BROKERS=redpanda:29092 -p 4000:4000 lechindianer/kafkaex_lag_exporter:0.2.0
 ```
 
 Now you can check the exposed metrics at [http://localhost:4000](http://localhost:4000).
 
+## Configuration
+
+KafkaExLagExporter uses 5 seconds as default interval to update the lags. If you want to configure it to use another
+value set `KAFKA_EX_INTERVAL_MS`, i.e.
+
+```bash
+docker run -ti --net="host" -e KAFKA_BROKERS=redpanda:29092 -e KAFKA_EX_INTERVAL_MS=10000 -p 4000:4000 \
+  lechindianer/kafkaex_lag_exporter:0.2.0
+```
+
 ## Developing
 
 To start the project locally:
@@ -38,11 +47,11 @@ To start the project locally:
 KAFKA_BROKERS="localhost:9092" iex -S mix 
 ```
 
-There is also a docker-compose file included which will start Kafka, serve Kowl (Web UI for Kafka) and start
+There is also a Docker compose file included which will start Kafka, serve Kowl (Web UI for Kafka) and start
 KafkaexLagExporter:
 
 ```bash 
-docker-compose up --build
+docker compose up --build
 ```
 
 Kowl is served at [http://localhost:8080](http://localhost:8080).

Tiltfile

@@ -1,3 +0,0 @@
-allow_k8s_contexts('default')
-
-include('konvert/Tiltfile')

config.yaml

@@ -1,8 +0,0 @@
-kafka:
-  brokers:
-    - kafka1:9092
-    - kafka2:9092
-    - kafka3:9092
-
-# server:
-  # listenPort: 8080

init_cluster.sh

@@ -1,15 +0,0 @@
-#!/usr/bin/env bash
-
-kind delete cluster
-
-kind create cluster --config kind.yaml
-
-kubectl wait -A --for=condition=ready pod --field-selector=status.phase!=Succeeded --timeout=15m
-
-kubectl get cm -n kube-system kube-proxy -o yaml | sed 's/maxPerCore.*/maxPerCore: 0/' | kubectl apply -n kube-system -f -
-
-kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.7.1/deploy/static/provider/kind/deploy.yaml
-
-LB_IP=$(kubectl get svc -n ingress-nginx ingress-nginx-controller -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
-
-echo "address=/kind.cluster/$LB_IP"

kind.yaml

@@ -1,24 +0,0 @@
-kind: Cluster
-apiVersion: kind.x-k8s.io/v1alpha4
-nodes:
-  - role: control-plane
-    kubeadmConfigPatches:
-      - |
-        kind: InitConfiguration
-        nodeRegistration:
-          kubeletExtraArgs:
-            node-labels: "ingress-ready=true"
-    extraPortMappings:
-      - containerPort: 80
-        hostPort: 80
-        protocol: TCP
-      - containerPort: 443
-        hostPort: 443
-        protocol: TCP
-#    image: kindest/node:v1.26.3@sha256:61b92f38dff6ccc29969e7aa154d34e38b89443af1a2c14e6cfbd2df6419c66f
-  - role: worker
-#    image: kindest/node:v1.26.3@sha256:61b92f38dff6ccc29969e7aa154d34e38b89443af1a2c14e6cfbd2df6419c66f
-  - role: worker
-#    image: kindest/node:v1.26.3@sha256:61b92f38dff6ccc29969e7aa154d34e38b89443af1a2c14e6cfbd2df6419c66f
-  - role: worker
-#    image: kindest/node:v1.26.3@sha256:61b92f38dff6ccc29969e7aa154d34e38b89443af1a2c14e6cfbd2df6419c66f

konvert/Tiltfile

@@ -1,21 +0,0 @@
-k8s_yaml('./redpanda-owl-shop-default-networkpolicy.yaml')
-k8s_yaml('./redpanda-persistentvolumeclaim.yaml')
-k8s_yaml('./redpanda-deployment.yaml')
-k8s_yaml('./redpanda-owl-shop-redpanda-network-networkpolicy.yaml')
-k8s_yaml('./redpanda-service.yaml')
-
-k8s_yaml('./connect-service.yaml')
-k8s_yaml('./connect-deployment.yaml')
-
-k8s_yaml('./owl-shop-deployment.yaml')
-
-k8s_yaml('./console-deployment.yaml')
-k8s_yaml('./console-service.yaml')
-k8s_yaml('./console-ingress.yaml')
-
-docker_build('kafka-lag-exporter', './..')
-
-k8s_yaml('./kafka-lag-exporter-deployment.yaml')
-k8s_yaml('./kafka-lag-exporter-service.yaml')
-
-k8s_resource(workload='kafka-lag-exporter', port_forwards=4000)

konvert/connect-deployment.yaml

@@ -1,48 +0,0 @@
-apiVersion: apps/v1
-kind: Deployment
-metadata:
-  creationTimestamp: null
-  labels:
-    io.kompose.service: connect
-  name: connect
-spec:
-  replicas: 1
-  selector:
-    matchLabels:
-      io.kompose.service: connect
-  template:
-    metadata:
-      labels:
-        io.kompose.network/redpanda-owl-shop-redpanda-network: "true"
-        io.kompose.service: connect
-    spec:
-      containers:
-        - env:
-            - name: CONNECT_BOOTSTRAP_SERVERS
-              value: redpanda:29092
-            - name: CONNECT_CONFIGURATION
-              value: |
-                key.converter=org.apache.kafka.connect.converters.ByteArrayConverter
-                value.converter=org.apache.kafka.connect.converters.ByteArrayConverter
-                group.id=connectors-cluster
-                offset.storage.topic=_internal_connectors_offsets
-                config.storage.topic=_internal_connectors_configs
-                status.storage.topic=_internal_connectors_status
-                config.storage.replication.factor=-1
-                offset.storage.replication.factor=-1
-                status.storage.replication.factor=-1
-                offset.flush.interval.ms=1000
-                producer.linger.ms=50
-                producer.batch.size=131072
-            - name: CONNECT_GC_LOG_ENABLED
-              value: "false"
-            - name: CONNECT_HEAP_OPTS
-              value: -Xms512M -Xmx512M
-            - name: CONNECT_LOG_LEVEL
-              value: info
-          image: docker.redpanda.com/redpandadata/connectors:latest
-          name: connect
-          ports:
-            - containerPort: 8083
-      hostname: connect
-      restartPolicy: Always

konvert/connect-service.yaml

@@ -1,13 +0,0 @@
-apiVersion: v1
-kind: Service
-metadata:
-  labels:
-    io.kompose.service: connect
-  name: connect
-spec:
-  ports:
-    - name: "8083"
-      port: 8083
-      targetPort: 8083
-  selector:
-    io.kompose.service: connect

konvert/console-deployment.yaml

@@ -1,48 +0,0 @@
-apiVersion: apps/v1
-kind: Deployment
-metadata:
-  creationTimestamp: null
-  labels:
-    io.kompose.service: console
-  name: console
-spec:
-  replicas: 1
-  selector:
-    matchLabels:
-      io.kompose.service: console
-  template:
-    metadata:
-      labels:
-        io.kompose.network/redpanda-owl-shop-redpanda-network: "true"
-        io.kompose.service: console
-    spec:
-      containers:
-        - args:
-            - -c
-            - echo "$(CONSOLE_CONFIG_FILE)" > /tmp/config.yml; /app/console
-          command:
-            - /bin/sh
-          env:
-            - name: CONFIG_FILEPATH
-              value: /tmp/config.yml
-            - name: CONSOLE_CONFIG_FILE
-              value: |
-                kafka:
-                  brokers: ["redpanda:29092"]
-                  schemaRegistry:
-                    enabled: true
-                    urls: ["http://redpanda:8081"]
-                redpanda:
-                  adminApi:
-                    enabled: true
-                    urls: ["http://redpanda:9644"]
-                connect:
-                  enabled: true
-                  clusters:
-                    - name: local-connect-cluster
-                      url: http://connect:8083
-          image: docker.redpanda.com/redpandadata/console:v2.2.4
-          name: console
-          ports:
-            - containerPort: 8080
-      restartPolicy: Always

konvert/console-ingress.yaml

@@ -1,17 +0,0 @@
-apiVersion: networking.k8s.io/v1
-kind: Ingress
-metadata:
-  name: ingress-myserviceb
-spec:
-  rules:
-    - host: console.lechindianer.hack
-      http:
-        paths:
-          - path: /
-            pathType: Prefix
-            backend:
-              service:
-                name: console
-                port:
-                  number: 8080
-  ingressClassName: nginx

konvert/console-service.yaml

@@ -1,13 +0,0 @@
-apiVersion: v1
-kind: Service
-metadata:
-  labels:
-    io.kompose.service: console
-  name: console
-spec:
-  ports:
-    - name: "8080"
-      port: 8080
-      targetPort: 8080
-  selector:
-    io.kompose.service: console

konvert/kafka-lag-exporter-deployment.yaml

@@ -1,26 +0,0 @@
-apiVersion: apps/v1
-kind: Deployment
-metadata:
-  labels:
-    io.kompose.service: kafka-lag-exporter
-  name: kafka-lag-exporter
-spec:
-  replicas: 1
-  selector:
-    matchLabels:
-      io.kompose.service: kafka-lag-exporter
-  template:
-    metadata:
-      labels:
-        io.kompose.network/redpanda-owl-shop-default: "true"
-        io.kompose.service: kafka-lag-exporter
-    spec:
-      containers:
-        - env:
-            - name: KAFKA_BROKERS
-              value: redpanda:29092
-          image: kafka-lag-exporter
-          name: kafka-lag-exporter
-          ports:
-            - containerPort: 4000
-      restartPolicy: Always

konvert/kafka-lag-exporter-service.yaml

@@ -1,13 +0,0 @@
-apiVersion: v1
-kind: Service
-metadata:
-  labels:
-    io.kompose.service: kafka-lag-exporter
-  name: kafka-lag-exporter
-spec:
-  ports:
-    - name: "4000"
-      port: 4000
-      targetPort: 4000
-  selector:
-    io.kompose.service: kafka-lag-exporter

konvert/owl-shop-deployment.yaml

@@ -1,31 +0,0 @@
-apiVersion: apps/v1
-kind: Deployment
-metadata:
-  labels:
-    io.kompose.service: owl-shop
-  name: owl-shop
-spec:
-  replicas: 1
-  selector:
-    matchLabels:
-      io.kompose.service: owl-shop
-  template:
-    metadata:
-      creationTimestamp: null
-      labels:
-        io.kompose.network/redpanda-owl-shop-redpanda-network: "true"
-        io.kompose.service: owl-shop
-    spec:
-      containers:
-        - env:
-            - name: SHOP_KAFKA_BROKERS
-              value: redpanda:29092
-            - name: SHOP_KAFKA_TOPICREPLICATIONFACTOR
-              value: "1"
-            - name: SHOP_TRAFFIC_INTERVAL_DURATION
-              value: 0.1s
-            - name: SHOP_TRAFFIC_INTERVAL_RATE
-              value: "6"
-          image: quay.io/cloudhut/owl-shop:latest
-          name: owl-shop
-      restartPolicy: Always

konvert/redpanda-deployment.yaml

@@ -1,44 +0,0 @@
-apiVersion: apps/v1
-kind: Deployment
-metadata:
-  labels:
-    io.kompose.service: redpanda
-  name: redpanda
-spec:
-  replicas: 1
-  selector:
-    matchLabels:
-      io.kompose.service: redpanda
-  strategy:
-    type: Recreate
-  template:
-    metadata:
-      labels:
-        io.kompose.network/redpanda-owl-shop-redpanda-network: "true"
-        io.kompose.service: redpanda
-    spec:
-      containers:
-        - args:
-            - redpanda start
-            - --smp 1
-            - --overprovisioned
-            - --kafka-addr PLAINTEXT://0.0.0.0:29092,OUTSIDE://0.0.0.0:9092
-            - --advertise-kafka-addr PLAINTEXT://redpanda:29092,OUTSIDE://localhost:9092
-            - --pandaproxy-addr 0.0.0.0:8082
-            - --advertise-pandaproxy-addr localhost:8082
-          image: docker.redpanda.com/redpandadata/redpanda:v23.1.8
-          name: redpanda
-          ports:
-            - containerPort: 8081
-            - containerPort: 8082
-            - containerPort: 9092
-            - containerPort: 9644
-            - containerPort: 29092
-          volumeMounts:
-            - mountPath: /var/lib/redpanda/data
-              name: redpanda
-      restartPolicy: Always
-      volumes:
-        - name: redpanda
-          persistentVolumeClaim:
-            claimName: redpanda

konvert/redpanda-owl-shop-default-networkpolicy.yaml

@@ -1,13 +0,0 @@
-apiVersion: networking.k8s.io/v1
-kind: NetworkPolicy
-metadata:
-  name: redpanda-owl-shop-default
-spec:
-  ingress:
-    - from:
-        - podSelector:
-            matchLabels:
-              io.kompose.network/redpanda-owl-shop-default: "true"
-  podSelector:
-    matchLabels:
-      io.kompose.network/redpanda-owl-shop-default: "true"

konvert/redpanda-owl-shop-redpanda-network-networkpolicy.yaml

@@ -1,13 +0,0 @@
-apiVersion: networking.k8s.io/v1
-kind: NetworkPolicy
-metadata:
-  name: redpanda-owl-shop-redpanda-network
-spec:
-  ingress:
-    - from:
-        - podSelector:
-            matchLabels:
-              io.kompose.network/redpanda-owl-shop-redpanda-network: "true"
-  podSelector:
-    matchLabels:
-      io.kompose.network/redpanda-owl-shop-redpanda-network: "true"

konvert/redpanda-persistentvolumeclaim.yaml

@@ -1,12 +0,0 @@
-apiVersion: v1
-kind: PersistentVolumeClaim
-metadata:
-  labels:
-    io.kompose.service: redpanda
-  name: redpanda
-spec:
-  accessModes:
-    - ReadWriteOnce
-  resources:
-    requests:
-      storage: 100Mi

konvert/redpanda-service.yaml

@@ -1,25 +0,0 @@
-apiVersion: v1
-kind: Service
-metadata:
-  labels:
-    io.kompose.service: redpanda
-  name: redpanda
-spec:
-  ports:
-    - name: "8081"
-      port: 8081
-      targetPort: 8081
-    - name: "8082"
-      port: 8082
-      targetPort: 8082
-    - name: "9092"
-      port: 9092
-      targetPort: 9092
-    - name: "9644"
-      port: 9644
-      targetPort: 9644
-    - name: "29092"
-      port: 29092
-      targetPort: 29092
-  selector:
-    io.kompose.service: redpanda

lib/kafkaex_lag_exporter/consumer_offset_runner.ex

@@ -5,8 +5,6 @@ defmodule KafkaexLagExporter.ConsumerOffsetRunner do
 
   require Logger
 
-  @interval 5_000
-
   def start_link(default) when is_list(default) do
     GenServer.start_link(__MODULE__, default, name: __MODULE__)
   end
@@ -18,23 +16,29 @@ defmodule KafkaexLagExporter.ConsumerOffsetRunner do
     clients = Application.get_env(:brod, :clients)
     endpoints = clients[:kafka_client][:endpoints] || [{"redpanda", 29_092}]
 
+    interval =
+      System.get_env("KAFKA_EX_INTERVAL_MS", "5000")
+      |> String.to_integer()
+
     Logger.info("Reveived Kafka endpoints: #{inspect(endpoints)}")
+    Logger.info("Updating lag information every #{interval} milliseconds")
 
-    Process.send_after(self(), :tick, @interval)
+    Process.send_after(self(), :tick, interval)
 
-    {:ok, %{endpoints: endpoints}}
+    {:ok, %{endpoints: endpoints, interval: interval}}
   end
 
   @impl true
   def handle_info(:tick, state) do
     [endpoint | _] = state.endpoints
+    interval = state.interval
 
     %{lags: lags, sum: lag_sum} = KafkaexLagExporter.ConsumerOffsetFetcher.get(endpoint)
 
     KafkaexLagExporter.Metrics.group_lag_per_partition(endpoint, lags)
     KafkaexLagExporter.Metrics.group_sum_lag(endpoint, lag_sum)
 
-    Process.send_after(self(), :tick, @interval)
+    Process.send_after(self(), :tick, interval)
 
     {:noreply, state}
   end

lib/kafkaex_lag_exporter/kafka_utils.ex

@@ -7,8 +7,6 @@ defmodule KafkaexLagExporter.KafkaUtils do
 
   alias KafkaexLagExporter.KafkaWrapper.Behaviour, as: KafkaWrapper
 
-  require Logger
-
   @default_client :client1
 
   def connection, do: connection(@default_client)
@@ -46,10 +44,7 @@ defmodule KafkaexLagExporter.KafkaUtils do
 
     group_descriptions
     |> Enum.flat_map(fn %{group_id: consumer_group, members: members} ->
-      get_member_info(members)
-      |> Enum.map(fn {topics, consumer_id, member_host} ->
-        {consumer_group, topics, consumer_id, member_host}
-      end)
+      get_member_info(consumer_group, members)
     end)
   end
 
@@ -63,7 +58,7 @@ defmodule KafkaexLagExporter.KafkaUtils do
       fetch_committed_offsets(topic, consumer_group, client)
       |> Enum.sort_by(fn {key, _value} -> key end)
 
-    for {{part, current}, {_part2, committed}} <- Enum.zip(offsets, committed_offsets) do
+    for {{part, current}, {_, committed}} <- Enum.zip(offsets, committed_offsets) do
       {part, current - committed}
     end
   end
@@ -75,8 +70,7 @@ defmodule KafkaexLagExporter.KafkaUtils do
     {:ok, partitions_count} = KafkaWrapper.get_partitions_count(client, topic)
 
     for i <- Range.new(0, partitions_count - 1),
-        {:ok, offset} =
-          KafkaWrapper.resolve_offset(endpoints, topic, i, :latest, sock_opts) do
+        {:ok, offset} = KafkaWrapper.resolve_offset(endpoints, topic, i, :latest, sock_opts) do
       {i, offset}
     end
   end
@@ -88,17 +82,22 @@ defmodule KafkaexLagExporter.KafkaUtils do
 
     {:ok, response} = KafkaWrapper.fetch_committed_offsets(endpoints, sock_opts, consumer_group)
 
-    for r <- response,
-        pr <- r[:partitions],
-        do: {pr[:partition_index], pr[:committed_offset]}
+    for r <- response, pr <- r[:partitions] do
+      {pr[:partition_index], pr[:committed_offset]}
+    end
   end
 
   @spec get_member_info(
+          binary,
           list(%{client_host: binary, member_assignment: binary, member_id: binary})
         ) ::
-          list({topic_names :: list(binary), consumer_id :: binary, member_host :: binary})
-  defp get_member_info(members) do
-    Enum.map(members, fn %{
+          list(
+            {consumer_group :: binary, topics :: list(binary), consumer_id :: binary,
+             member_host :: binary}
+          )
+  defp get_member_info(consumer_group, members) do
+    members
+    |> Enum.map(fn %{
                      client_host: member_host,
                      member_assignment: member_assignment,
                      member_id: consumer_id
@@ -106,5 +105,8 @@ defmodule KafkaexLagExporter.KafkaUtils do
       topics = KafkaexLagExporter.TopicNameParser.parse_topic_names(member_assignment)
       {topics, consumer_id, member_host}
     end)
+    |> Enum.map(fn {topics, consumer_id, member_host} ->
+      {consumer_group, topics, consumer_id, member_host}
+    end)
   end
 end