Troubleshooting & Debugging Magento2 in Docker
Ariya InfoTech
February 12, 2025
When running Magento2 in a Docker environment, issues are bound to arise, especially as Magento2 can be quite resource-intensive. Understanding how to troubleshoot and debug Magento2 in Docker is crucial for keeping your development and production environments stable.
At Ariya InfoTech, we handle a lot of Magento2 in Docker environments, and Yuvraj Raulji, a seasoned Magento2 expert, shares:
“Docker provides a robust environment for Magento2, but knowing how to debug and troubleshoot common issues ensures smooth development and deployment.”
In this guide, we’ll walk you through some common issues, debugging techniques, and best practices to resolve Magento2 issues in Docker.
Why Troubleshooting Magento2 in Docker?
✅ Resolve container issues – Debug problems related to services like PHP, MySQL, Redis, Elasticsearch, etc.
✅ Improve performance – Fix bottlenecks in Docker containers affecting Magento2 speed.
✅ Identify configuration errors – Spot and fix configuration issues in the docker-compose.yml or Magento settings.
✅ Ensure stability – Ensure all dependencies work together smoothly for long-term stability.
Step 1: Check Docker Container Logs
Magento2 containers can generate logs for every service. The first step in troubleshooting is to check these logs.
1.1 View Logs for Specific Containers
To see logs for a particular container (e.g., PHP container), run:
CopyEdit
docker logs magento_app
For MySQL, use:
CopyEdit
docker logs magento_db
Similarly, for Nginx or other containers, use:
CopyEdit
docker logs magento_nginx
Logs provide information about issues like:
- Database connection errors
- PHP issues (e.g., memory limits or execution time)
- Nginx server misconfigurations
1.2 View Real-time Logs
You can also tail logs in real-time for debugging:
CopyEdit
docker logs -f magento_app
Step 2: Inspect Docker Containers' Health and Status
Docker containers can sometimes fail or exit unexpectedly. You can use the following commands to check container status and resource usage:
2.1 Check Container Status
CopyEdit
docker ps -a
2.2 Check Resource Usage
CopyEdit
docker stats
Step 3: Magento2 Specific Issues
3.1 Common Magento2 Errors in Docker
Error: “Database Connection Error”
Check MySQL Container Logs:
sh
CopyEdit
docker logs magento_db
Ensure MySQL Container is Running:
sh
CopyEdit
docker ps
Make sure the magento_db container is up. If it isn’t, restart Docker Compose:
sh
CopyEdit
docker-compose up -d
Error: “Magento 2 Not Loading or Blank Page”
Enable Magento2 Debugging
CopyEdit
docker exec -it magento_app bin/magento setup:config:set –enable-debug-logging=1
After enabling debugging, check the logs:
sh
CopyEdit
docker exec -it magento_app tail -f var/log/system.log
docker exec -it magento_app tail -f var/log/exception.log
Check PHP-FPM & Nginx Logs:
CopyEdit
docker exec -it magento_app tail -f /var/log/php-fpm.log
Check Nginx error logs:
sh
CopyEdit
docker exec -it magento_nginx tail -f /var/log/nginx/error.log
Step 4: Resolve Common Docker Configuration Issues
4.1 Container Startup Issues
Sometimes containers fail to start because of misconfigured environment variables or port conflicts.
- Check for Port Conflicts: Ensure no other services are using the same port as your Docker containers. For instance, if your Nginx container is trying to use port 80, ensure that port is free.
- Verify Environment Variables: Double-check the docker-compose.yml file for the correct configuration of environment variables, such as database credentials, session storage, etc.
Restart Docker Containers:
If you made changes to docker-compose.yml, restart the containers:
CopyEdit
docker-compose down
docker-compose up -d
4.2 Magento Permission Issues in Docker
Fix Permissions:
CopyEdit
docker exec -it magento_app chmod -R 777 var/ pub/ generated/
Set Correct Ownership:
Fix ownership:
CopyEdit
docker exec -it magento_app chown -R www-data:www-data var/ pub/ generated/
Step 5: Debugging Elasticsearch & Redis Issues
5.1 Elasticsearch Issues
Magento2 relies heavily on Elasticsearch for search functionality. If Elasticsearch isn’t working:
Check Elasticsearch Logs:
Run:
CopyEdit
docker logs magento_elasticsearch
Look for errors related to Elasticsearch startup, such as insufficient memory or configuration errors.
Check Elasticsearch Connectivity:
Verify Magento can connect to Elasticsearch:
CopyEdit
docker exec -it magento_app bin/magento config:set catalog/search/engine elasticsearch7
docker exec -it magento_app bin/magento indexer:reindex
Ensure Elasticsearch is Running:
Run:
CopyEdit
docker ps
If Elasticsearch is not running, restart the container:
sh
CopyEdit
docker-compose restart elasticsearch
5.2 Redis Issues
Redis is used for caching and session storage. If Redis isn’t working:
Check Redis Logs:
Run:
CopyEdit
docker logs magento_redis
Ensure Redis Connectivity in Magento:
Run:
CopyEdit
docker exec -it magento_app bin/magento setup:config:set –cache-backend=redis –cache-backend-redis-server=redis
docker exec -it magento_app bin/magento cache:flush
Step 6: Debugging Docker Compose Issues
6.1 Configuration Changes
If you need to make changes to the Docker setup (e.g., adding services or modifying configurations), follow these steps:
Update the Docker Compose File:
Make changes to docker-compose.yml as needed. After updating, restart containers:
CopyEdit
docker-compose down
docker-compose up -d
6.2 Docker Compose Build Issues
If you encounter build issues:
Rebuild Containers:
CopyEdit
docker-compose build
Clear Docker Cache:
If the build fails repeatedly, clear the Docker cache and rebuild:
CopyEdit
docker builder prune
Final Thoughts
Troubleshooting Magento2 in Docker is a crucial skill for developers and system administrators. With the right knowledge, you can quickly diagnose and resolve issues like database connectivity problems, PHP errors, and misconfigurations. At Ariya InfoTech, we ensure that our Magento2 in Docker deployments are smooth, efficient, and stable.
Next Steps: Stay tuned for our next guide on Scaling Magento2 with Kubernetes and Docker Swarm for high-traffic stores.
