Porting a Linux Container (LXC) to Docker might seem like a straightforward task given that both are containerization technologies. However, there are several caveats and pitfalls that one should be aware of before attempting this process.

LXC and Docker are both used to create and manage containers, but they operate on different underlying principles. LXC is more of a lightweight virtualization method that provides an environment similar to a full-fledged virtual machine. Docker, on the other hand, is a platform for developing, shipping, and running applications inside containers, optimized for microservices and cloud-native applications.

Here are the key issues to be aware of when porting an LXC container to Docker:

• Different Container Philosophies:
  • LXC containers are closer to traditional virtual machines, providing a more complete operating system environment.
  • Docker containers are designed to run a single application or service, following a microservice architecture.

• File System Differences:
  • LXC uses a full OS filesystem, while Docker uses layered filesystems.
  • You may need to manually adjust file paths and configurations when moving to Docker.

• Process Management:
  • LXC containers manage multiple processes similarly to a traditional Linux environment.
  • Docker is designed to run a single process per container. This might require refactoring of the services running in the LXC container.

• Networking:
  • LXC networking configurations can be complex and highly customized.
  • Docker abstracts much of the networking and provides simpler, yet different, networking options which might require reconfiguration.

• Security Contexts:
  • LXC provides a more traditional Linux security model.
  • Docker has a different security model, with its own set of user namespaces, capabilities, and SELinux/AppArmor profiles, which might affect how applications behave.

• Resource Allocation:
  • LXC provides finer control over resource allocation (CPU, memory, etc.).
  • Docker abstracts and automates much of this, which could lead to different performance characteristics.

Porting from LXC to Docker is not a trivial task due to the differences in how these containers are designed and managed. It's essential to review the services, configurations, and workflows involved before starting the migration to avoid unexpected issues and ensure that your applications run smoothly in Docker.

• Docker documentation: https://docs.docker.com/
• LXC documentation: https://linuxcontainers.org/lxc/introduction/