Docker menggunakan ciri kernel Linux — namespace (pengasingan), cgroup (kawalan sumber), dan sistem fail kesatuan (union filesystem) (imej berlapis) — untuk mencipta kontena yang ringan. Memahami mekanisme asas menjelaskan cara kontena mencapai pengasingan dan kecekapan.
Namespace — pengasingan
Linux NAMESPACES isolate what a process can SEE — giving each container its own view:
PID namespace → its own process tree (container sees only its processes)
NET namespace → its own network interfaces, IPs, ports
MNT namespace → its own filesystem mounts
UTS namespace → its own hostname
IPC, USER namespaces → isolated IPC, user/group ID mapping
→ Namespaces are WHY a container feels like a separate machine (isolated view),
while actually sharing the host kernel.
