docs: add docker-compose template

[emaxerrno]

A good starting point

version: '3.7'
services:
  redpanda:
    entrypoint:
    - /usr/bin/rpk
    - redpanda
    - start
    - --smp
    - '1'
    - --reserve-memory
    - 0M
    - --overprovisioned
    - --node-id
    - '0'
    - --kafka-addr
    - PLAINTEXT://0.0.0.0:29092,OUTSIDE://0.0.0.0:9092
    - --advertise-kafka-addr
    - PLAINTEXT://kafka:29092,OUTSIDE://localhost:9092
    - --
    - --kernel-page-cache
    - '1'
    image: vectorized/redpanda:v21.4.1
    ports:
    - 9092:9092
    - 29092:29092
    volumes:
    - redpanda:/var/lib/redpanda/data
volumes:
  redpanda: null

[emaxerrno]

@BenPope maybe we show case it with a python app or the javascript app/getting started.

[emaxerrno]

I added this in 4c72cd6 as a base.

[manstis]

FWIW, here's a docker-compose.yml file that connects Redpanda to Kafdrop.

It's based on the template in this issue.. for which I am grateful as I was really struggling.

version: '3.7'
services:
  redpanda:
    entrypoint:
    - /usr/bin/rpk
    - redpanda
    - start
    - --smp
    - '1'
    - --reserve-memory
    - 0M
    - --overprovisioned
    - --node-id
    - '0'
    - --kafka-addr
    - INSIDE://0.0.0.0:9093,OUTSIDE://0.0.0.0:9092
    - --advertise-kafka-addr
    - INSIDE://redpanda:9093,OUTSIDE://localhost:9092
    - --
    - --kernel-page-cache
    - '1'
    image: vectorized/redpanda:v21.4.1
    ports:
    - "9092:9092"
    expose:
    - "9093"
    volumes:
    - redpanda:/var/lib/redpanda/data

  kafdrop:
    image: obsidiandynamics/kafdrop
    depends_on:
      - redpanda
    ports:
      - "9000:9000"
    environment:
      KAFKA_BROKERCONNECT: "redpanda:9093"
      JVM_OPTS: "-Xms32M -Xmx64M"
      SERVER_SERVLET_CONTEXTPATH: "/"

volumes:
  redpanda: null