Docker and Compose
Docker Compose security checklist
Reduce container risk with trusted fixed image versions, limited access, protected secrets, narrow networks and regular updates.
By AppLaunch Editorial · Reviewed 2026-08-25
Direct answer
Use trusted images with fixed versions, run without the root account where possible, remove unneeded permissions, make files read-only when the application does not need to change them, expose only required ports and protect secrets. Keep the host and images updated because containers do not remove the need for security maintenance.
What this means in plain English
Containers reduce some kinds of accidental interference, but they do not remove the need for security. Use trusted versioned images, update them, run with as little permission as possible and expose only ports that real users or systems need.
Avoid giving ordinary application containers control of Docker itself. Mounting the Docker socket or running privileged can give a compromised app control over the whole host. Protect secrets and important volumes, and plan how to rebuild after an incident.
Which controls reduce the ways an attacker can get in?
| Software source | Fixed trusted image and vulnerability review |
|---|---|
| Access | Non-root account, minimal permissions and folder access |
| Exposure | Only the required public ports and network paths |
A simple example
A small web container runs as a non-root user, reads a single database secret, writes only to its upload volume and connects only to the app and database networks. It cannot manage Docker or browse unrelated host folders.
What to do, step by step
1. List images, ports, mounted folders and special permissions.
Start here before buying anything or changing several settings at once. It gives you a clear starting point based on software source: fixed trusted image and vulnerability review. Write the result down so you can compare it later.
2. Remove Docker socket access unless it is essential.
Use the same files, versions and settings that the real project will use. A quick test with an empty or different setup can look successful while completely missing the problem you are trying to solve.
3. Patch and rebuild on a defined schedule.
Try the busiest realistic situation, not the easiest one. Include the people, data, traffic or background work you genuinely expect, then watch for slowdowns and errors rather than relying on a single headline number.
4. Test how damage is contained and how credentials are changed.
Finish by checking the result against exposure: only the required public ports and network paths. Keep the old setting or release available until you know the change works and can be reversed safely.
One more useful tip
Remove old images and services only after confirming they are not needed for rollback. Security cleanup should not accidentally destroy the one working recovery path.
Common mistakes and how to avoid them
Mounting /var/run/docker.sock into ordinary apps.
This gives a misleading or unsafe result because it leaves out software source. A better approach is to list images, ports, mounted folders and special permissions, then check the result before making the change permanent.
Running with full privileges by default.
This gives a misleading or unsafe result because it leaves out access. A better approach is to remove docker socket access unless it is essential, then check the result before making the change permanent.
Keeping abandoned base images.
This gives a misleading or unsafe result because it leaves out exposure. A better approach is to patch and rebuild on a defined schedule, then check the result before making the change permanent.
Words explained
- container
- A packaged, isolated way to run an application with the files and software it needs.
- image
- The read-only package used to create a container. A good production image can be rebuilt and traced back to a specific release.
- Compose
- Docker Compose is a file-based way to describe several containers, their settings, storage and networks as one application.
- secret
- A password, token or key that must not be committed to source control or exposed to users.
Quick checklist
- List images, ports, mounted folders and special permissions.
- Remove Docker socket access unless it is essential.
- Patch and rebuild on a defined schedule.
- Test how damage is contained and how credentials are changed.
Common questions
What is the simple answer?
Use trusted images with fixed versions, run without the root account where possible, remove unneeded permissions, make files read-only when the application does not need to change them, expose only required ports and protect secrets. Keep the host and images updated because containers do not remove the need for security maintenance.
What should I check first?
Start with software source: fixed trusted image and vulnerability review. That is usually more useful than choosing from a marketing label or copying somebody else’s setting.
How can I make the change safely?
List images, ports, mounted folders and special permissions. Then change one thing at a time, keep a backup or old version, and use the same real-world test after each change.
What is the easiest mistake to avoid?
Mounting /var/run/docker.sock into ordinary apps. Avoiding that one mistake makes the rest of the comparison much more trustworthy.