When you run a lot of Docker containers, it can be hard to see what is going on. Each container writes logs and these logs might be important. They help you know if something is broken. They also help you understand how your app is working.
But logs from many containers on many servers? That can get messy. This is why people use centralized logging. Centralized logging means all logs go to one place so that you can look at them easily.
In this post, we will talk about how to collect logs from Docker. We will see what tools people use. And we will look at the pros and cons of each.
Why Logs Matter
Logs are like notes that your app writes. These notes say what the app is doing. If the app crashes, the logs can tell you why. If users have problems, the logs help you understand them.
Without logs, fixing bugs is like guessing. Logs are your flashlight in the dark.
How Docker Logs Work
Docker containers run apps. These apps write logs. By default, Docker collects these logs. You can see them with:
docker logs <container-name>
But this only works for one container at a time. If you have 10 containers, you must run the command 10 times. Not fun.
Also, if your container crashes and restarts, old logs may be gone. So we need a better way.
Centralized Logging
Centralized logging means you collect all logs from all containers. You send them to one place and this place stores the logs. It shows you the logs in a nice way.
There are many tools for this. Let’s look at some of them.
1. ELK Stack (Elasticsearch, Logstash, Kibana)
The ELK Stack is a popular open-source solution for log management.
Logstash collects and processes logs from different sources, and sends them to Elasticsearch. Elasticsearch stores and indexes the data so you can search it quickly. Kibana lets you view and explore the logs in a dashboard. It’s powerful, but setting it up and running it can be heavy on resources and hard to manage.
Pros:
- Powerful query and search capabilities.
- Tons of community support and documentation.
- Kibana has rich visualizations.
Cons:
- Complex to deploy and maintain.
- High resource usage (RAM, CPU, disk).
- Too complex for small apps.
Best for: Big teams with time to manage it.
2. Loki + Promtail + Grafana
🔗 Loki
Loki is a log aggregation system made by the creators of Grafana. Promtail is the agent that collects logs from files or containers and sends them to Loki. Grafana is used to search and visualize the logs. It’s much lighter than ELK and easy to use if you already work with Grafana. Loki works best with Grafana — using it without Grafana is possible, but not ideal.
Pros:
- Easier than ELK.
- Uses less memory.
- Works well with Prometheus.
Cons:
- Less powerful than ELK.
- Needs many pieces to work.
Best for: People who already use Grafana.
3. Graylog
🔗 Graylog
Graylog is a log management tool that works with structured and unstructured logs. You can collect logs from Docker using the GELF log driver or tools like Filebeat. It stores and indexes the logs so you can search and filter them later. Graylog can be self-hosted for free, or used as a managed cloud service if you want. Setup is flexible but might need more steps compared to simpler tools.
Pros:
- Clean UI.
- Easy to use search.
- More user-friendly than raw ELK
Cons:
- Still needs Elasticsearch.
- Scaling can get complex.
- Not super light.
Best for: Teams who want ELK but easier.
4. DockStats
DockStats is a lightweight, and probably the simplest, cloud-based platform made for Docker users. You install a small agent on your servers, and it collects logs and system metrics. The data is sent securely to the DockStats dashboard where you can search and filter it. There's no need for complex setup — just one agent and you're ready to go.
Pros:
- No configuration needed — plug and play
- Collects logs from all Docker containers.
- Logs and metrics in one place.
Cons:
- Still new, many features still coming.
- Small but growing community
Best for: Developers who run Docker without Kubernetes. Especially if you self-host everything.
What Should You Use?
It really depends on what you need and how much time and energy you want to spend.
If you want something powerful and flexible, and you don’t mind a complex setup, the ELK Stack is a strong choice. But be ready to deal with memory usage, configuration files, and maybe even a full-time person to manage it.
If you already use Grafana and like simple tools, then Loki + Promtail might be perfect. It’s easier to run than ELK, and it works well for most use cases. But keep in mind, it’s mainly built for Grafana, so if you don’t use Grafana, it might feel limited.
If you like to customize everything and want a mix of open-source and enterprise features, Graylog could work. It gives you a lot of control and different ways to collect logs. But again, setup can take some time, especially if you're new to it.
If you're self-hosting apps in Docker and just want something quick, easy, and made for developers, DockStats is worth trying. You just drop in one agent, and you get a clean dashboard for logs and metrics, without having to manage big systems or deal with Elasticsearch. It’s also a nice fit if you're running many small servers and want everything in one place without stress.
There’s no one-size-fits-all, but now you have a better idea of what each tool does — so pick the one that feels right for your project. ✅
Final Words
Logs are important. If you run Docker apps, logs help you stay in control.
Start with something simple. You can always change later.
Happy logging! 🐳
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