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
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
messagebus:x:27:27:D-Bus
Message Daemon User:/dev/null:/bin/false
User for D-Bus
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:
wheel:x:39:
nogroup:x:65533:
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
messagebus:x:27:
User for D-Bus
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.linuxbase.org) 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.
The login, agetty, and init programs (and others) use a number of log files to record information such as who was logged into the system and when. However, these programs will not write to the log files if they do not already exist. Initialize the log files and give them proper permissions:
touch ${CLFS}/var/log/{btmp,lastlog,wtmp}
chgrp -v 13 ${CLFS}/var/log/lastlog
chmod -v 664 ${CLFS}/var/log/lastlog
chmod -v 600 ${CLFS}/var/log/btmp
The /var/log/wtmp file records all
logins and logouts. The /var/log/lastlog file records when each user last
logged in. The /var/log/btmp file
records the bad login attempts.