Run MySQL in docker with latency to simulate network

docker-compose.yml

 services:
  mysql:
    # instead of image: mysql:5.7-debian
    build: ./docker/mysql-with-traffic-control
    cap_add:
      - NET_ADMIN
    ports:
      - "3306:3306"
    environment:
      MYSQL_DATABASE: flyingcars
      MYSQL_USER: zephod
      MYSQL_PASSWORD: child
      MYSQL_ROOT_PASSWORD: not-so-secret!
      # comment out to have no latency added. 20ms seems sufficient to unearth perf issues
      LATENCY_MS: 20

    command: 
      # 
      - "--default-authentication-plugin=mysql_native_password"
      - "--lower_case_table_names=1"
      - "--character-set-server=utf8"
      - "--collation-server=utf8_general_ci"
    volumes:
      - "./mysql-db:/var/lib/mysql"

Dockerfile

# Dockerfile - saved in ./docker/mysql-with-traffic-control
FROM mysql:5.7-debian

# Add MySQL APT repository key
RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys B7B3B788A8D3785C

# Install iproute2 for the `tc` command (NOTE ; instead of & because update still complains about key)
RUN apt-get update; apt-get install -y iproute2 && rm -rf /var/lib/apt/lists/*

# Copy the latency script into the container
COPY start_with_latency.sh /usr/local/bin/start_with_latency.sh
RUN chmod +x /usr/local/bin/start_with_latency.sh

# Override the entrypoint to include the latency script
ENTRYPOINT ["/usr/local/bin/start_with_latency.sh"]
CMD ["mysqld"]

start_with_latency.sh

#!/bin/bash

# Start MySQL in the background
docker-entrypoint.sh "$@" &

# Add latency if LATENCY_MS is set and greater than 0
if [ "${LATENCY_MS:-0}" -gt 0 ]; then
  tc qdisc add dev eth0 root netem delay "${LATENCY_MS}ms"
  echo "Added ${LATENCY_MS}ms of latency to eth0"
fi

# Wait for MySQL to exit
wait -n