One of the goals of containers are to unify the development and deployment environments. I hate developing and testing code in containers, so I develop and test code outside them and then package and test it again in a container.

Containerized apps need a lot of special boilerplate to determine how much CPU and memory they are allowed to use. It’s a lot easier to control resource limits with virtual machines because the application in the system resources are all dedicated to the application.

Orchestration of multiple containers for dev environments is just short of feature complete. With Compose, it’s hard to bring down specific services and their dependencies so you can then rebuild and rerun. I end up writing Ansible playbooks to start and stop components that are designed to be executed in particular sequences. Ansible makes it hard to detach a container, wait a specified time, and see if it’s running. Compose just needs to be updated to support management of shutting down and restarting containers, so I can move away from Ansible.

Services like Kafka that query the host name and broadcast it are difficult to containerize since the host name inside the container doesn’t match the external host name. Requires manual overrides which are hard to specify at run time because the orchestrators don’t make it easy to pass in the host name to the container. (This is more of a Kafka issue, though.)