Learning notes

k8s in action

Learning notes about k8s in action

Chapter 1: Namespace and cgroup

• namespace is used isolate processes
• since parent process and child process are in the same pid namespace, they can see similar number of processes
• ps -ef to list all processes
• echo $$ to list current process pid
• echo $PPID to list parent process pid
• ls -l /proc/14356/ns to list pid 14356 namespaces
• /sys/fs/cgroup is the place where user space and kernel interact about cgroup settings
• use unshare command to specify the namespace that a child process doesn't want to share with its parent.
• dmesg -T | grep "oom" is used to check kernel message about out of memory error

Chapter 2: