linuxexpert-practice-labs/labs/lfcs/5-2-environment-profiles/README.md

LFCS 5.2: Environment profiles

Setting variables, PATH entries and aliases in the right startup files: for everyone, for one user, and for users created later.

Before you start

The lab creates users erin and frank (password Lab-Pass-1, shell bash) and a directory /opt/tools/bin with a small tool in it. So that le-lab check can test ssh sessions, it puts a lab key in their ~/.ssh/authorized_keys. Reset puts /etc/skel, /etc/profile.d, /etc/environment, the system bashrc and root's own startup files back as they were.

Tasks

1. Set COMPANY=example for every user's login shell, without editing /etc/profile. Test it with sudo -iu erin printenv COMPANY.
2. Give every new user an alias lt='ls -ltr' and a README file in their home directory. Test it with useradd -m testuser, then sudo -iu testuser bash -ic 'alias lt' and ls /home/testuser; remove testuser again afterwards.
3. Add /opt/tools/bin to erin's PATH permanently, and only to hers: frank's PATH must not have it.
4. Set HTTP_PROXY=http://proxy.example.org:3128 for every session, including ssh host command. Test it with ssh erin@localhost printenv HTTP_PROXY.

Hints

• /etc/profile.d/*.sh; check with sudo -iu USER printenv.
• /etc/skel and the .bashrc in it; useradd -m.
• ~/.bash_profile (RHEL family) or ~/.profile (Debian, Ubuntu).
• /etc/environment, read by pam_env; no export, no $VARIABLES.