> For the complete documentation index, see [llms.txt](https://mrinalghimire.com.np/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mrinalghimire.com.np/assignment-1/assignment-2-solution.md). # Assignment 2 - Solution **Author:** Mrinal Ghimire *** ## 1. Create User Accounts ### Objective Create: * Group **testing** * User **natasha** (secondary group: testing) * User **harry** (secondary group: testing) * User **sarah** (no interactive shell and not a member of testing) All users should have the password: ``` flectrag ``` *** ### Step 1: Create Group ```bash sudo groupadd testing ``` #### Verify ```bash getent group testing ``` *** ### Step 2: Create Users #### Natasha ```bash sudo useradd -m -G testing natasha ``` #### Harry ```bash sudo useradd -m -G testing harry ``` #### Sarah ```bash sudo useradd -m -s /usr/sbin/nologin sarah ``` > On some distributions the shell may be `/sbin/nologin`. *** ### Step 3: Set Password ```bash echo "natasha:flectrag" | sudo chpasswd echo "harry:flectrag" | sudo chpasswd echo "sarah:flectrag" | sudo chpasswd ``` *** ### Verify ```bash id natasha id harry id sarah ``` Expected: * Natasha → member of testing * Harry → member of testing * Sarah → not in testing *** ## 2. Create a Collaborative Directory ### Objective Create ``` /home/admins ``` Requirements * Group owner = testing * Members of testing can read, write and enter * Others have no access * Files inherit the testing group automatically *** ### Step 1 ```bash sudo mkdir /home/admins ``` *** ### Step 2 Change group ownership. ```bash sudo chgrp testing /home/admins ``` *** ### Step 3 Set permissions and SGID bit. ```bash sudo chmod 2770 /home/admins ``` #### Explanation * 2 → SGID * 7 → Owner rwx * 7 → Group rwx * 0 → Others no permission Verify ```bash ls -ld /home/admins ``` Expected ``` drwxrws--- ``` *** ## 3. Configure /var/tmp/fstab Permissions ### Copy File ```bash sudo cp /etc/fstab /var/tmp/fstab ``` *** ### Set Owner ```bash sudo chown root:root /var/tmp/fstab ``` *** ### Remove Execute Permission ```bash sudo chmod 644 /var/tmp/fstab ``` *** ### Configure ACL Allow natasha read/write ```bash sudo setfacl -m u:natasha:rw /var/tmp/fstab ``` Deny harry ```bash sudo setfacl -m u:harry:--- /var/tmp/fstab ``` Verify ```bash getfacl /var/tmp/fstab ``` #### Why ACL? Standard Linux permissions cannot allow one specific user while denying another. ACLs provide fine-grained permissions. *** ## 4. Configure a Cron Job Login as natasha. ```bash su - natasha ``` Open cron. ```bash crontab -e ``` Add ```cron 23 14 * * * /bin/echo hello ``` Save. Verify ```bash crontab -l ``` #### Explanation ``` Minute Hour Day Month Weekday Command ``` ``` 23 14 * * * ``` means every day at **2:23 PM**. *** ## 5. Create a Compressed Archive ### Objective Archive ``` /tmp ``` into ``` /var/tmp/tmp.tar.bz2 ``` using **bzip2** compression. *** ### Command ```bash sudo tar -cjf /var/tmp/tmp.tar.bz2 /tmp ``` #### Explanation * c → create archive * j → bzip2 compression * f → output file *** ### Verify ```bash ls -lh /var/tmp/tmp.tar.bz2 ``` List archive contents ```bash tar -tjf /var/tmp/tmp.tar.bz2 ``` *** ## Verification Commands ### Users ```bash id natasha id harry id sarah ``` ### Group ```bash getent group testing ``` ### Directory ```bash ls -ld /home/admins ``` ### ACL ```bash getfacl /var/tmp/fstab ``` ### Cron ```bash crontab -l ``` ### Archive ```bash ls -lh /var/tmp/tmp.tar.bz2 ``` *** ## Conclusion In this assignment, we successfully: * Created users and groups * Managed group memberships * Configured a collaborative directory using SGID * Applied file permissions and ACLs * Scheduled a cron job * Created a compressed tar archive using bzip2 These are essential Linux administration tasks commonly performed by system administrators in production environments. --- # Agent Instructions This documentation is published with GitBook. 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