Expo CLI - Docker

Sample set up of Expo within a Docker environment

Table of Contents

• Requirements
• Prerequisite Commands
• Common Issues and Workarounds
  • Metro Bundler
  • Local Area Network (LAN) Host Name
• Additional Resources

Requirements

• Docker Engine version 18.06.0+
• Docker-Compose version 1.22.0+

Prerequisite Commands

docker-compose up -d
docker exec -it expo_docker /bin/bash
expo init CoolAppInit #typescript

Common Issues and Workarounds

Metro Bundler

Could not get status from Metro bundler. connect ECONNREFUSED 127.0.0.1:19003
Connecting to Metro bundler failed.

Workaround: Removing the .expo directory rm -rf .expo and killing processes within the Docker container that relate to the expo or yarn commands or the project directory ps au will display all processes and kill -9 PID will kill the process(es).

USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root       261  0.2  2.6 882240 54408 pts/1    Sl+  06:52   0:03 node /usr/local/bin/yarn ios
root       272  0.0  0.0   4280   748 pts/1    S+   06:52   0:00 /bin/sh -c expo start --ios
root       273  0.0  1.5 563424 31140 pts/1    Sl+  06:52   0:00 /usr/local/bin/node /expo_docker/CoolAppInit/nod
root       280  8.2  8.7 1006040 178688 pts/1  Sl+  06:52   2:11 /usr/local/bin/node /usr/local/bin/expo-cli star
root       324 14.7  8.6 998796 175856 pts/1   Sl+  06:52   3:54 /usr/local/bin/node /expo_docker/CoolAppInit/nod

Local Area Network (LAN) Host Name

One can only connect to the Expo Server when providing the host machine's IP address or host name
MY_LAN_IP=123.456.789.1 docker-compose up -d

Additional Resources

• React Native
• Expo
• Expo Documentation