NAMEnss-mymachines, libnss_mymachines.so.2 - Provide hostname resolution for local container instances.
nss-mymachines is a plug-in module for the GNU Name Service Switch (NSS) functionality of the GNU C Library (glibc), providing hostname resolution for the names of containers running locally that are registered with systemd-machined.service(8). The container names are resolved to the IP addresses of the specific container, ordered by their scope. This functionality only applies to containers using network namespacing.
The module also resolves user and group IDs used by containers to user and group names indicating the container name, and back. This functionality only applies to containers using user namespacing.
To activate the NSS module, add "mymachines" to the lines starting with "hosts:", "passwd:" and "group:" in /etc/nsswitch.conf.
It is recommended to place "mymachines" after the "files" or "compat" entry of the /etc/nsswitch.conf lines to make sure that its mappings are preferred over other resolvers such as DNS, but so that /etc/hosts, /etc/passwd and /etc/group based mappings take precedence.
Here is an example /etc/nsswitch.conf file that enables nss-mymachines correctly:
passwd: compat mymachines systemd group: compat mymachines systemd shadow: compat hosts: files mymachines resolve [!UNAVAIL=return] dns myhostname networks: files protocols: db files services: db files ethers: db files rpc: db files netgroup: nis