Container lifecycle management encompasses the complete journey of a container from creation through termination, including state transitions, process handling, and cleanup. Understanding lifecycle mechanics is critical for building resilient containerized applications that start correctly, handle signals gracefully, and shut down without data loss or dropped connections. The most common pitfall is the PID 1 problem—when your main process doesn't properly reap zombie children or handle termination signals, leading to resource leaks and unclean shutdowns that orchestrators like Kubernetes misinterpret as application failures.
What This Cheat Sheet Covers
This topic spans 13 focused tables and 94 indexed concepts. Below is a complete table-by-table outline of this topic, spanning foundational concepts through advanced details.
Table 1: Container States
| State | Example | Description |
|---|---|---|
docker create nginx | • Container exists but has not been started • filesystem and config are prepared but no process is running. | |
docker start my-container | • Main process (PID 1) is executing • container is operational and consuming resources. | |
docker pause my-container | • All processes frozen via cgroup freezer • memory state preserved but CPU execution halted. |