Lab catalog
77 labs · 11 tracks77 of 77loading…
Loading…
-
Netplan: restore the link to the neighbour The training interface lab0 is up, yet the neighbour 192.0.2.1 does not answer. Find the cause and fix the persistent network configuration without touching anything else.Networking ~25 min not started
-
A service behind the neighbour The reports service on node2 answers itself, but a request from node1 waits and gives up. Find where the path gets lost and fix it so that the fix survives a reboot.Networking ~30 min not started
-
Ports: start the app service The app web service will not start. Find out what is in its way and bring it up on its usual port, 8080.Networking ~20 min not started
-
Firewall: open the site to the office The server's site must open from the office and stay closed to everyone else, yet the office waits until the timeout. Find the cause and fix the persistent nftables configuration.Networking ~25 min not started
-
Internal names do not resolve The name app.internal does not resolve, although the DNS server runs on this very machine. Find out why the system does not ask it and fix that.Networking ~15 min not started
-
SSH key login isn't working The key for deploy is on the server, yet the login is refused. Use the log to find what the server distrusts and restore the login.Networking ~20 min not started
-
Keep only the authorized SSH access A dedicated SSH server on 127.0.0.1:2222 lets in too many. Leave key-only access for deploy, deny root and check a fresh connection.Networking ~25 min not started
-
Connect two VMs over the network The site works on node2, but a request from node1 waits and gives up. Find on which machine and at which stage it gets lost, and restore access.Networking ~30 min not started
-
Site unreachable from another host The site on node2 answers itself but does not open from node1. There may be several causes — find them all and keep nginx healthy.Networking ~40 min not started
-
Root partition is full A service stopped saving data: the disk is full. Find what took the space and free it without touching the service's data.Storage ~15 min not started
-
Find the actual space consumer The file list says a huge image fills the data volume, yet df disagrees. Find out what really occupies the blocks and write a report without deleting anything.Storage ~20 min not started
-
/data is empty after a reboot After a reboot the service cannot find its data: /data is empty. Mount the data disk so that it also mounts at boot.Storage ~20 min not started
-
Move the data to a new disk The application's data sits in /srv/data on the root partition, and a new empty disk has been attached for it. Prepare the disk and mount it at /srv/data so that it also mounts after a reboot.Storage ~25 min not started
-
Grow the data volume There is almost no space left in /data, and the data must not be deleted. Give the volume more room without repartitioning or losing data.Storage ~25 min not started
-
Return a volume to a consistent snapshot A training update damaged the data on a volume, and an LVM snapshot was taken just before it. Roll the volume back to the snapshot and put it back in service.Storage ~25 min not started
-
Restore an app from a tar archive The app broke after an update. Prepare a restored copy from the archive next to the working one, complete and with the archived modes.Storage ~20 min not started
-
Bring a directory mirror up to date (rsync) A directory mirror has fallen behind its source. Make it an exact copy and leave both the source and the neighbouring data intact.Storage ~25 min not started
-
A report from the nginx log The five longest requests and the bytes per response code for one day, from an nginx log cut in two by rotation.Bash: text processing and scripts ~30 min not started
-
Change an address in every config The backend has moved: thirty configs with the address written in different ways, and the comments and similar addresses must stay.Bash: text processing and scripts ~25 min not started
-
Fix the report script The upload check script lets empty files through, cuts names apart and hides failures — bring it up to its contract.Bash: text processing and scripts ~25 min not started
No lab on the topic you need? Suggest a lab