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Dear Community,
While trying to install python3-scapy on one of the hosts getting :
“Temporary failure in name resolution”.
The full error is :
“sudo: unable to resolve host a83f476a-af0e-4b07-8a63-7d1cb0f6c300-h1: Temporary failure in name resolution
W: Failed to fetch http://nova.clouds.archive.ubuntu.com/ubuntu/dists/focal/InRelease Temporary failure resolving ‘nova.clouds.archive.ubuntu.com’
W: Failed to fetch http://nova.clouds.archive.ubuntu.com/ubuntu/dists/focal-updates/InRelease Temporary failure resolving ‘nova.clouds.archive.ubuntu.com’
W: Failed to fetch http://nova.clouds.archive.ubuntu.com/ubuntu/dists/focal-backports/InRelease Temporary failure resolving ‘nova.clouds.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.
sudo: unable to resolve host a83f476a-af0e-4b07-8a63-7d1cb0f6c300-h1: Temporary failure in name resolution
E: Unable to locate package python3-scapy”
Do I need to configure the internet separately? How can I resolve the issue? The image of the error is on the attachment.
Kind regards,
Nagmat
The error “sudo: unable to resolve host a83f476a-af0e-4b07-8a63-7d1cb0f6c300-h1” is normal since there is no name resolution for this.
As for the Ubuntu repositories, There was an issue with some Ubuntu Repos yesterday worldwide. Try this again today. If it still does not work, please post the contents of the /etc/resolv.conf file from your machine.
The error “sudo: unable to resolve host a83f476a-af0e-4b07-8a63-7d1cb0f6c300-h1” is normal since there is no name resolution for this.
As for the Ubuntu repositories, There was an issue with some Ubuntu Repos yesterday worldwide. Try this again today. If it still does not work, please post the contents of the /etc/resolv.conf file from your machine.
The issue is still there.
The content of /etc/resolve.conf is :
“# This file is managed by man:systemd-resolved(8). Do not edit.
# This is a dynamic resolv.conf file for connecting local clients to the
# internal DNS stub resolver of systemd-resolved. This file lists all
# configured search domains.
# Run “resolvectl status” to see details about the uplink DNS servers
# currently in use.
# Third party programs must not access this file directly, but only through the
# symlink at /etc/resolv.conf. To manage man:resolv.conf(5) in a different way,
# replace this symlink by a static file or a different symlink.
# See man:systemd-resolved.service(8) for details about the supported modes of
# operation for /etc/resolv.conf.
options edns0 trust-ad
search openstacklocal”
The error I am getting is :
“sudo: unable to resolve host a83f476a-af0e-4b07-8a63-7d1cb0f6c300-h1: Temporary failure in name resolution
W: Failed to fetch http://nova.clouds.archive.ubuntu.com/ubuntu/dists/focal/InRelease Temporary failure resolving ‘nova.clouds.archive.ubuntu.com’
W: Failed to fetch http://nova.clouds.archive.ubuntu.com/ubuntu/dists/focal-updates/InRelease Temporary failure resolving ‘nova.clouds.archive.ubuntu.com’
W: Failed to fetch http://nova.clouds.archive.ubuntu.com/ubuntu/dists/focal-backports/InRelease Temporary failure resolving ‘nova.clouds.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.
sudo: unable to resolve host a83f476a-af0e-4b07-8a63-7d1cb0f6c300-h1: Temporary failure in name resolution
E: Unable to locate package python3-scapy”
I believe the Issue is with the DNS servers the Ubuntu images at NCSA end up using. Rocky Linux seems to pick up the right DNS servers but Ubuntu image are not at NCSA.
If you switch to using 2606:4700:4700::1111, 2620:0:c80:2::1, 2620:0:c80:2::3 these DNS server, it should work.
I am investigation on a proper fix , but this will be a workaround for now.
I’m going in circles on this workaround. To change the DNS server, I thought I would need to edit /etc/resolve.conf. This requires root privileges. That isn’t possible if sudo doesn’t work. What’s the way around this?
You do have sudo access on your machine to edit this. But please read online posts regarding editing DNS settings for Ubuntu. UBUNTU 18 and higher use systemd-resolved (or resovectl) to make changes to DNS settings. Due to a bug at the NCSA site. ubuntu seems to be picking up DNS servers that are restricted by the hosting site(NCSA).
2606:4700:4700::1111, 2620:0:c80:2::1, 2620:0:c80:2::3 these three DNS servers should work, but i am unable to find the right command to overwrite the settings in resolvectl. The commands i have tried just add these servers to the existing list which does not help. Using Rocky Linux or some other FABRIC Site may work.
Sadly, I’m getting the same sudo error in other FABRIC sites (not NCSA). I’d like to use Ubuntu; I’m trying to benchmark an existing project, built on Linux and which requires cloning from Github. I’d imagine I could run it on Rocky Linux, but I don’t want to have to write additional installation scripts for various dependencies. Is there any workaround, or is Rocky my best bet?
I have two VMs on DALL. Their management IP addresses are 2001:400:a100:3000:f816:3eff:fed0:4779 and 2001:400:a100:3000:f816:3eff:fe62:fc9a.
I dont see any issues on your VM.
i tried this in your VM and it seems to do the right thing
ubuntu@e0a0baa2-fbe3-4d6b-92b9-6d1c74b93897-ei11:~$ sudo apt install python3-scapy
Is there a reason the behavior would differ between SSH’ing onto the node and executing commands through the Jupyter notebook? It’s not letting me upload a screenshot, but the behavior is roughly:
node.execute(f’sudo apt update’)
sudo: unable to resolve host e0a0baa2-fbe3-4d6b-92b9-6d1c74b93897-ei11: Name or service not known
To provide a reproducible example:
from fabrictestbed_extensions.fablib.fablib import FablibManager as fablib_manager fablib = fablib_manager() slice_name = 'ei-2node' slice = fablib.get_slice(name=slice_name) node_name = 'ei11' node = slice.get_node(name=node_name) node.execute(f’sudo apt update’)resulting in:
sudo: unable to resolve host e0a0baa2-fbe3-4d6b-92b9-6d1c74b93897-ei11: Name or service not knownAs i mentioned before that sudo error is normal. I am not sure if the node.execute() just stops due to that or if it proceeds and fails silently at the apt command . apt is an interactive tool. To run it non-interactively requires a lot more options.
https://stackoverflow.com/questions/33370297/apt-get-update-non-interactive
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