Issue on lab 9.3: Working with CoreDNS

Here again for another issue on the 9.3 lab: my pod cannot resolve addresses.
After a lot of problems, as described in my past discussion, I recreate the entire cluster, so I'm now able to go ahead, but, reached this lab (9.3) I found another problem. The feeling is that the coredns doesn't work correctly, I restart them, but the problem persists.
I provide here some information and configuration, hoping that someone can help me to identify the problem.
Status of the coredns pods
**kubectl get pods --all-namespaces | grep coredns** kube-system coredns-6b4b86d8bf-2r222 1/1 Running 0 12m kube-system coredns-6b4b86d8bf-nqj2m 1/1 Running 0 12m
my /etc/resolve.conf file on the host
nameserver 127.0.0.53 options edns0 trust-ad search homenet.telecomitalia.it
/etc/resolve.conf file on nettool pod
nameserver 10.96.0.10 search default.svc.cluster.local svc.cluster.local cluster.local homenet.telecomitalia.it options ndots:5
Output of the apt update command executed in the pod
root@nettool:/# apt update Err:1 http://security.ubuntu.com/ubuntu focal-security InRelease Temporary failure resolving 'security.ubuntu.com' Err:2 http://archive.ubuntu.com/ubuntu focal InRelease Temporary failure resolving 'archive.ubuntu.com' Err:3 http://archive.ubuntu.com/ubuntu focal-updates InRelease Temporary failure resolving 'archive.ubuntu.com' Err:4 http://archive.ubuntu.com/ubuntu focal-backports InRelease Temporary failure resolving 'archive.ubuntu.com' Reading package lists... Done Building dependency tree Reading state information... Done All packages are up to date. W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/focal/InRelease Temporary failure resolving 'archive.ubuntu.com' W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/focal-updates/InRelease Temporary failure resolving 'archive.ubuntu.com' W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/focal-backports/InRelease Temporary failure resolving 'archive.ubuntu.com' W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/focal-security/InRelease Temporary failure resolving 'security.ubuntu.com' W: Some index files failed to download. They have been ignored, or old ones used instead.
Log from the coredns pods
**kubectl logs coredns-6b4b86d8bf-2r222 --namespace kube-system ** .:53 [INFO] plugin/reload: Running configuration MD5 = db32ca3650231d74073ff4cf814959a7 CoreDNS-1.7.0 linux/amd64, go1.14.4, f59c03d [ERROR] plugin/errors: 2 2411310349111695803.1156763954485922933. HINFO: read udp 192.168.140.134:50073->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 2411310349111695803.1156763954485922933. HINFO: read udp 192.168.140.134:53444->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 2411310349111695803.1156763954485922933. HINFO: read udp 192.168.140.134:33483->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 2411310349111695803.1156763954485922933. HINFO: read udp 192.168.140.134:60055->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 2411310349111695803.1156763954485922933. HINFO: read udp 192.168.140.134:45734->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 2411310349111695803.1156763954485922933. HINFO: read udp 192.168.140.134:58277->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 2411310349111695803.1156763954485922933. HINFO: read udp 192.168.140.134:48417->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 2411310349111695803.1156763954485922933. HINFO: read udp 192.168.140.134:45403->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 2411310349111695803.1156763954485922933. HINFO: read udp 192.168.140.134:43683->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 2411310349111695803.1156763954485922933. HINFO: read udp 192.168.140.134:52890->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 security.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:40467->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:55114->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:54780->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 security.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:32826->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.140.134:34987->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:57937->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:54716->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.140.134:37758->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:48427->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:39343->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.140.134:55263->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 security.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:51377->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:35208->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 security.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:45064->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 security.ubuntu.com. A: read udp 192.168.140.134:36542->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 security.ubuntu.com. A: read udp 192.168.140.134:59127->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.140.134:52336->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.140.134:55511->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:58522->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.140.134:48809->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 security.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:59664->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:44874->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 security.ubuntu.com. A: read udp 192.168.140.134:50931->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.140.134:34514->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:54530->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:45994->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.140.134:60092->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:39119->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com.homenet.telecomitalia.it. A: read udp 192.168.140.134:59702->192.168.1.1:53: i/o timeout [ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.140.134:45259->192.168.1.1:53: i/o timeout
Can someone help me to understand where I mistaking?
Thanks in advance!
Andy74
Comments
-
Hi @andrea.calvario,
The issue you are experiencing at this point seems to be related to how your Internet Service Provider operates. It is trying to locate
*.ubuntu.com
onhomenet.telecomitalia.it
domain.With a simple google search I was able to find a forum post that should provide you with a solution around the DNS issues with telecomitalia. I hope it helps to fix your host's
resolv.conf
file:https://forum.ubuntu-it.org/viewtopic.php?t=428583
Regards,
-Chris0 -
Hi,
I am experiencing the same issue but the logs don't show the same error related with ISP (until I can understand). Is there something I can do?
These are the logs from both CoreDNS pods:
ablo@pablo-VirtualBox:~$ kubectl -n kube-system logs coredns-f9fd979d6-2nd2n
.:53
[INFO] plugin/reload: Running configuration MD5 = 823e90b886243896bc5fc311d1fe380f
CoreDNS-1.7.0
linux/amd64, go1.14.4, f59c03d
[ERROR] plugin/errors: 2 5854889205053853889.4992786380578661315. HINFO: read udp 192.168.54.36:36158->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 5854889205053853889.4992786380578661315. HINFO: read udp 192.168.54.36:37468->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 5854889205053853889.4992786380578661315. HINFO: read udp 192.168.54.36:33847->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 5854889205053853889.4992786380578661315. HINFO: read udp 192.168.54.36:58102->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 5854889205053853889.4992786380578661315. HINFO: read udp 192.168.54.36:56101->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 5854889205053853889.4992786380578661315. HINFO: read udp 192.168.54.36:35935->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 5854889205053853889.4992786380578661315. HINFO: read udp 192.168.54.36:49304->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 5854889205053853889.4992786380578661315. HINFO: read udp 192.168.54.36:37233->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 5854889205053853889.4992786380578661315. HINFO: read udp 192.168.54.36:58338->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 5854889205053853889.4992786380578661315. HINFO: read udp 192.168.54.36:56906->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 security.ubuntu.com. A: read udp 192.168.54.36:44621->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.54.36:39647->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.54.36:43970->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.54.36:49128->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.54.36:43476->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.54.36:54778->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.54.36:35449->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.54.36:32906->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.54.36:39382->192.168.18.1:53: i/o timeout
pablo@pablo-VirtualBox:~$ kubectl -n kube-system logs coredns-f9fd979d6-sbmlw
.:53
[INFO] plugin/reload: Running configuration MD5 = 823e90b886243896bc5fc311d1fe380f
CoreDNS-1.7.0
linux/amd64, go1.14.4, f59c03d
[ERROR] plugin/errors: 2 7925864582003874829.5346898514191063070. HINFO: read udp 192.168.54.39:49955->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 7925864582003874829.5346898514191063070. HINFO: read udp 192.168.54.39:47710->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 7925864582003874829.5346898514191063070. HINFO: read udp 192.168.54.39:36716->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 7925864582003874829.5346898514191063070. HINFO: read udp 192.168.54.39:60608->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 7925864582003874829.5346898514191063070. HINFO: read udp 192.168.54.39:39340->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 7925864582003874829.5346898514191063070. HINFO: read udp 192.168.54.39:57446->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 7925864582003874829.5346898514191063070. HINFO: read udp 192.168.54.39:42763->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 security.ubuntu.com. A: read udp 192.168.54.39:53249->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.54.39:42660->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.54.39:32993->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 security.ubuntu.com. A: read udp 192.168.54.39:54913->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 security.ubuntu.com. A: read udp 192.168.54.39:35481->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.54.39:59322->192.168.18.1:53: i/o timeout
[ERROR] plugin/errors: 2 archive.ubuntu.com. A: read udp 192.168.54.39:48382->192.168.18.1:53: i/o timeoutAs you can see I am working with virtual machines, so far, I haven´t had DNS issues.
Any information will be appreciated
Pablo A.
0 -
Hello,
Did you read through the link provided, about checking your VM DNS settings? Are your VMs able to resolve DNS names? Are all of the pods running when you run kubectl get pods --all-namespaces ?
Regards,
0 -
I had the same issue running on debian 10. I installed the resolvconf package and changed the DNS on the masternode from my local DNS (192.168.1.1) to external DNS (1.1.1.1). And of course a static IP configured on the node. That solved it for me.
1 -
Hi, thank you for your answers. I had already checked the pods out and they were always running. Finally, I followed the RonaldHeirbaut recommendation and downloaded the resolvconf package on the masternode and after that, my pod was able to download the dig and other tools needed for the practice.
0
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