Building Enterprise JavaScript Applications

Namespaces

Namespaces package system resources, such as filesystems, network access, and so on, and present them to a process. From the view of the process, it does not even know that there are resources outside of its allocation.

One of the resources that can be namespaced is process IDs (PIDs). In Linux, PIDs are organized as a tree, with the system’s initiation process (systemd) given the PID 1, and located at the root of the tree.

If we namespace PIDs, we are masking a child process from the rest of the processes, by resetting the root of the child process to have a PID of 1. This means descendant processes will treat the child process as if it is a root, and they will have no knowledge of any other processes past that point:

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