Kubernetes 101 - Part12 - Debug pod

When it comes to troubleshooting application connectivity and name resolution issues in Kubernetes, having the right tools at your disposal can make all the difference. One of the most common challenges is accessing essential utilities like ping, nslookup, dig, traceroute, and more. To simplify this process, we've created a container image that packs a range of these utilities, making it easy to quickly identify and resolve connectivity issues.

 

The Container Image: A Swiss Army Knife for Troubleshooting

This container image, designed specifically for Kubernetes troubleshooting, comes pre-installed with the following essential utilities:

1. ping: A classic network diagnostic tool for testing connectivity.
   
2. dig: A DNS lookup tool for resolving domain names to IP addresses.
3. nslookup: A network troubleshooting tool for resolving hostnames to IP addresses.
4. traceroute: A network diagnostic tool for tracing the path of packets across a network.
5. curl: A command-line tool for transferring data to and from a web server using HTTP, HTTPS, SCP, SFTP, TFTP, and more.
6. wget: A command-line tool for downloading files from the web.
7. nc: A command-line tool for reading and writing data to a network socket.
8. netstat: A command-line tool for displaying network connections, routing tables, and interface statistics.
9. ifconfig: A command-line tool for configuring network interfaces.
10. route: A command-line tool for displaying and modifying the IP routing table.
11. host: A command-line tool for performing DNS lookups and resolving hostnames.
12. arp: A command-line tool for displaying and modifying the ARP cache.
13. iostat: A command-line tool for displaying disk I/O statistics.
14. top: A command-line tool for displaying system resource usage.
15. free: A command-line tool for displaying free memory and swap space.
16. vmstat: A command-line tool for displaying virtual memory statistics.
17. pmap: A command-line tool for displaying process memory maps.
18. mpstat: A command-line tool for displaying multiprocessor statistics.
19. python3: A programming language and interpreter.
20. pip: A package installer for Python.

 

Run as a pod on Kubernetes

❯ kubectl run debug --image=vineethac/debug -n default -- sleep infinity

 

Exec into the debug pod

❯ kubectl exec -it debug -n default -- bash 
root@debug:/# ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=46 time=49.3 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=45 time=57.4 ms
64 bytes from 8.8.8.8: icmp_seq=3 ttl=46 time=49.4 ms
^C
--- 8.8.8.8 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2003ms
rtt min/avg/max/mdev = 49.334/52.030/57.404/3.799 ms
root@debug:/#
root@debug:/# nslookup google.com
Server:		10.96.0.10
Address:	10.96.0.10#53

Non-authoritative answer:
Name:	google.com
Address: 142.250.72.206
Name:	google.com
Address: 2607:f8b0:4005:80c::200e

root@debug:/# exit
exit
❯

 

Reference

https://github.com/vineethac/Docker/tree/main/debug-image

By having these essential utilities at your fingertips, you'll be better equipped to quickly identify and resolve connectivity issues in your Kubernetes cluster, saving you time and reducing the complexity of troubleshooting.

Hope it was useful. Cheers!

Configure syslog forwarding in vCenter servers using Python

As a system administrator, it's essential to ensure that your vCenter servers are properly configured to collect and forward system logs to a central location for monitoring and analysis. In this blog, we'll explore how to configure syslog forwarding in vCenter servers using Python.

You can access the Python script from my GitHub repository: 
https://github.com/vineethac/VMware/tree/main/vCenter/syslog_forwarding

In this blog, we've demonstrated how to get, test, and set syslog forwarding configuration in vCenter servers using Python. By following these steps, you can ensure that your vCenter servers are properly configured to collect and forward system logs to a central location for monitoring and analysis. Remember to replace the placeholders in the config file with your actual vCenter server names, syslog server IP address or hostname, port, and protocol.

Hope it was useful. Cheers!

Anatomy of Hyper-V cluster debug log

• Get-ClusterLog dumps the events to a text file
• Location: C:\Windows\Clsuter\Reports\Cluster.log
• It captures last 72 hours log
• Cluster log is in GMT (because of geographically spanned multi-site clusters)
• Usage: Get-ClusterLog -timespan (which gives last "x" minutes logs)
• You can also set the levels of logs
• Set-ClusterLog -Level 3 (level 3 is default)
• It can be from level 0 to level 5 (increasing level of logging has performance impact)
• Level 5 will provide the highest level of detail
• Log format:
  [ProcessID] [ThreadID] [Date/Time] [INFO/WARN/ERR/DBG] [RescouceType] [ResourceName] [Description]