RHEL7: How to solve “ import read failed(2)”? - linux

I am trying to add Docker’s public key for CS packages using the following command( which is taken from the link https://docs.docker.com/docker-trusted-registry/install/install-csengine/):
sudo rpm --import "https://sks-keyservers.net/pks/lookup?op=get&search=0xee6d536cf7dc86e2d7d56f59a178ac6c6238f52e"
However, I am getting the following error on running the above command:
curl: (6) Could not resolve host: sks-keyservers.net; Name or service not known
error: https://sks-keyservers.net/pks/lookup?op=get&search=0xee6d536cf7dc86e2d7d56f59a178ac6c6238f52e: import read failed(2).
Is it a firewall issue??
Please let me know if I need to add a host entry in /etc/hosts?

This problem is caused by your firewall, enable / disable it and try again
systemctl disable firewalld
systemctl stop firewalld
or
systemctl enable firewalld
systemctl start firewalld

Related

Unit firewalld.service is masked

When I want to start the firewalld service, I got this error
[root#servera ~]# systemctl start firewalld
Failed to start firewalld.service: Unit firewalld.service is masked.
and I searched in the web and got a solution that run systemctl unmask firewalld, but it is not working, others get a message Removed symlink /etc/systemd/system/firewalld.service. but I got nothing.
When I want to enable this service, I got an error
[root#servera ~]# systemctl enable firewalld
Failed to enable unit: Unit file /usr/lib/systemd/system/firewalld.service is masked.
It's abnormal, because it's /usr/lib/systemd/system/firewalld.service, not /etc/systemd/system/firewalld.service
Any hints? Thanks!
I have tried
systemctl unmask firewalld
but it's no response and not working

raspberry pi (No APs found)

I tried to create a static IP address using the mobile hotspot by making changes in the file shown below enter image description hereand later I removed the static IP by commenting out the changes after which, I get two cross marks near the WLAN network and it says no APs found and WLAN0 not associated. I tried rebooting the OS many times still the same please somebody help me
Please check if this helps:
sudo systemctl daemon-reload
sudo systemctl start dhcpcd.service
# or if dhcpcd is already running:
sudo systemctl restart dhcpcd.service
From: https://raspberrypi.stackexchange.com/a/70609

jupyterlab 500 error from dataproc cluster

i have been trying to open jupyterlab from my dataproc cluster. i had been working on it last week and there seemed to be some issue with the kernel. so i signed out of jupyterlab and stopped the cluster. then i tried to open jupyterlab again from the link under web interfaces in cluster detail. however, since last wednesday, everytime i try this i get a 500 or 502 error. the error says "500. That's an error. That's all we know."
i'm not sure what to do here. i googled the issue and couldn't find anything that would help.
You can SSH into the master node with gcloud compute ssh <cluster-name>-m, then check the status of the following 3 services:
systemctl status jupyter
systemctl status knox
systemctl status google-dataproc-component-gateway
Restart them if needed:
sudo systemctl restart jupyter
sudo systemctl restart knox
sudo systemctl restart google-dataproc-component-gateway
Also, check the Knox log at /var/log/knox/gateway.log.

How to enable firewall on Centos 7?

My firewall is currently inactive.
# systemctl status firewalld
firewalld.service
Loaded: masked (/dev/null)
Active: inactive (dead)
I used the following command to enable the firewall
$systemctl unmask firewalld
but I got this error
# systemctl unmask firewalld
Failed to issue method call: Access denied
Please advise.
Thanks in advance!
Try this:
systemctl unmask firewalld
return: Removed symlink /etc/systemd/system/firewalld.service.
After that, you can:
systemctl restart firewalld
Try this:
sudo systemctl restart firewalld
sudo systemctl enable firewalld
But before you should install firewalld. You can use yum for that:
sudo yum install firewalld

Cannot restart network service

I was trying to configure a static IP address on my Linux machine (Fedora 19 ). However when I was trying to restart my network.services using systemctl restart network.service, I was unable to do so.
[root#xyz network-scripts]# systemctl restart network.service
Job failed. See system journal and 'systemctl status' for details.
I tried to reboot my system and re execute the command, but still I am getting the same error. Also I am enable to access internet on my system.
Can anyone help me out with this.
To restart network services, you can use this command
service networking restart
You can also use
service networking stop
then
service networking start
restart the nm-applet with this command from terminal:
killall nm-applet; nohup nm-applet &
or restart the the network manager service using:
sudo systemctl restart network-manager
Restore radio frequencies by running the following command;
sudo service NetworkManager restart
If that does not work, run this one;
rfkill unblock wifi

Resources