7.14. Creating the passwd and group Files

In order for user root to be able to login and for the name “root” to be recognized, there must be relevant entries in the /etc/passwd and /etc/group files.

Create the ${CLFS}/etc/passwd file by running the following command:

cat > ${CLFS}/etc/passwd << "EOF"
root::0:0:root:/root:/bin/bash
bin:x:1:1:/bin:/bin/false
daemon:x:2:6:/sbin:/bin/false
messagebus:x:27:27:D-Bus Message Daemon User:/dev/null:/bin/false
systemd-bus-proxy:x:71:72:systemd Bus Proxy:/:/bin/false
systemd-journal-gateway:x:73:73:systemd Journal Gateway:/:/bin/false
systemd-journal-remote:x:74:74:systemd Journal Remote:/:/bin/false
systemd-journal-upload:x:75:75:systemd Journal Upload:/:/bin/false
systemd-network:x:76:76:systemd Network Management:/:/bin/false
systemd-resolve:x:77:77:systemd Resolver:/:/bin/false
systemd-timesync:x:78:78:systemd Time Synchronization:/:/bin/false
systemd-coredump:x:79:79:systemd Core Dumper:/:/bin/false
nobody:x:65534:65533:Unprivileged User:/dev/null:/bin/false
EOF

The actual password for root (the “::” used here is just a placeholder and allows you to login with no password) will be set later.

Additional users you may want to add if not already included:

adm:x:3:16:adm:/var/adm:/bin/false

Was used for programs that performed administrative tasks.

lp:x:10:9:lp:/var/spool/lp:/bin/false

Used by programs for printing

mail:x:30:30:mail:/var/mail:/bin/false

Often used by email programs

news:x:31:31:news:/var/spool/news:/bin/false

Often used for network news servers

operator:x:50:0:operator:/root:/bin/bash

Often used to allow system operators to access the system

postmaster:x:51:30:postmaster:/var/spool/mail:/bin/false

Generally used as an account that receives all the information of troubles with the mail server

Create the ${CLFS}/etc/group file by running the following command:

cat > ${CLFS}/etc/group << "EOF"
root:x:0:
bin:x:1:
sys:x:2:
kmem:x:3:
tty:x:5:
tape:x:4:
daemon:x:6:
floppy:x:7:
disk:x:8:
lp:x:9:
dialout:x:10:
audio:x:11:
video:x:12:
utmp:x:13:
usb:x:14:
cdrom:x:15:
adm:x:16:
mail:x:30:
messagebus:x:27:
nogroup:x:65533:
systemd-bus-proxy:x:72:
systemd-journal:x:28:
systemd-journal-gateway:x:73:
systemd-journal-remote:x:74:
systemd-journal-upload:x:75:
systemd-network:x:76:
systemd-resolve:x:77:
systemd-timesync:x:78:
systemd-coredump:x:79:
wheel:x:39:
EOF

Additional groups you may want to add if not already included:

console:x:17:

This group has direct access to the console

cdrw:x:18:

This group is allowed to use the CDRW drive

news:x:31:news

Used by Network News Servers

users:x:1000:

The default GID used by shadow for new users

nobody:x:65533:

This is used by NFS

The created groups are not part of any standard—they are groups decided on in part by the requirements of the Systemd configuration in the final system, and in part by common convention employed by a number of existing Linux distributions. The Linux Standard Base (LSB, available at http://www.linuxfoundation.org/collaborate/workgroups/lsb) recommends only that, besides the group “root” with a Group ID (GID) of 0, a group “bin” with a GID of 1 be present. All other group names and GIDs can be chosen freely by the system administrator since well-written programs do not depend on GID numbers, but rather use the group's name.