62
votes
Accepted
No network connectivity to/from Docker CE container on CentOS 8
After spending a couple of days looking at logs and configurations for the involved components, I was about to throw in the towel and revert back to Fedora 30, where this seems to work straight out of ...
- 1,183
13
votes
No network connectivity to/from Docker CE container on CentOS 8
What's missing from the answers before is the fact that you first need to add your docker interface to the zone you configure, e.g. public (or add it to the "trusted" zone which was suggested here but ...
- 333
12
votes
Accepted
firewalld is not working in CentOS 8: no rule at all is created in iptables
Because you don't see any iptables rule, doesn't mean firewalld is not working. Actually firewalld switched to using nftables as backend. So you can find your rules with for example:
nft list ruleset
...
- 10.4k
8
votes
Accepted
Failing to run yum update in CentOS 8
The infra that is behind vault.centos.org will likely always going to be flaky.
RedHat has very little motivation to support it. It is for archived community version of their primary OS, the very same ...
- 5,146
7
votes
How do I update a system from CentOS 7 to CentOS 8?
Red Hat provide the tool leapp to upgrade from EL 7.6+ to 8, however according to this CentOS bug, there are no plans to support it on CentOS. Trying to point an existing 7.x machine to the 8.x repos ...
- 4,741
7
votes
Can't mount CentOS NFS share on Windows 10 - "Network Error - 53"
On the Linux part - make sure your NFS Server Configuration is correct:
nfs-utils and nfs-utils-lib should be installed
rpcbind, nfs-server, nfs-lock, nfs-idmap should be enabled
rpcbind, nfs-...
- 3,048
6
votes
Yum on Centos 8 - Failed to download metadata for repo 'AppStream'
Apparently not the problem here, but if you have pinned yourself to CentOS 8.1.1911 you will get the same error until you re-point your /etc/yum.repos.d/ repositories at http://vault.centos.org ...
- 161
6
votes
Accepted
"dnf update" vs. "yum update" command differences in CentOS Linux?
yum was replaced with dnf in CentOS 8. The command yum still exists because people will still remember it for years to come. The only thing it does is to call dnf.
[root@localhost ~]# ls -l /usr/bin/...
- 242k
6
votes
Again enabled SELINUX and now the user logins wont work in enforcing mode
Running with Selinux disabled for a long time can cause files to not be labelled or labelled with Selinux context not matching the installed policy. Also daemons and other processes (including systemd)...
- 136
6
votes
Dell R620 with PERC s110 and LSI Centos 8 not discovering RAID drives
DELL S110 is nothing more than a fancy name for Intel software RAID (see the SATA controller specification). It depends on a device driver being present in Windows which effectively run the software ...
- 46.3k
6
votes
Accepted
What replaces "ntpq" in CentOS 8?
as of rhel8, the NTP protocol is implemented by the chronyd daemon. you can use chronyc sources
- 249
5
votes
Accepted
How to determine if my CentOS 8 is vulnerable to CVE-2019-18348
You are on the right track following the Red Hat Service Advisory. The same package that resolves CVE/RHSA upstream will be released for CentOS. Sometimes it is not available as quickly. There is a ...
- 12.5k
5
votes
No network connectivity to/from Docker CE container on CentOS 8
To be able to set fine-grained rules for Docker, I did not need to set docker0 to any zone.
# 1. Stop Docker
systemctl stop docker
# 2. Recreate DOCKER-USER chain in firewalld.
firewall-cmd --...
- 185
5
votes
Accepted
Ansible Centos 8 dnf module "module" switch missing?
You can install a module (which is essentially a group of packages) by adding a @ prior to the name of the module to the name parameter of the Ansible dnf module. It can be used like this:
- name: ...
- 9,206
5
votes
Accepted
Can't run command under /bin/false user
Setting the default shell to /bin/false means that su will switch user, and then execute
/bin/false -c /opt/tomcat/bin/startup.sh
You can use the -s option to su to override the setting in /etc/...
- 3,287
5
votes
Accepted
CentOS 9 Stream - errors doing yum update
baseos CentOS Stream 9 - BaseOS
epel Extra Packages for Enterprise Linux 7 - x86_64
extras-common CentOS Stream 9 - Extras packages
You are using old EPEL (and "remi") for ...
- 2,111
4
votes
No network connectivity to/from Docker CE container on CentOS 8
I have changed the FirewallBackend variable to iptables again and it works for me.
With this update, the nftables filtering subsystem is the default
firewall backend for the firewalld daemon. To ...
- 141
4
votes
How do I update a system from CentOS 7 to CentOS 8?
There are manuals around with bugs, so try this (see comments). If something fails, you need to resolve the issue or it won't work. Some steps are hard to reverse and you may end up with unbootable ...
- 371
4
votes
Issue running Golang server binary as a service with Systemd
I found the problem!
It was due to the SELinux policy, which was denying Systemd to run my server app as a service, as it was in a non-standard bin directory /var/mybin/.
you can verify the SELinux ...
- 367
4
votes
Accepted
How much does httpd_can_network_connect being set to 1 actually open up on SELinux
how much this actually opens up from a security standpoint
A lot. As you may have guessed it allows httpd_t to talk to any remote servers.
There is no specification for which website it is, and it ...
- 5,146
4
votes
Accepted
Remi: Which repository contains what?
As a general rule you should enable remi-safe, remi and remi-modular (but all three of these should already be enabled). These repos together contain the packages and module streams you expected to ...
- 242k
4
votes
Accepted
Deactivate default ports of systemd socket activation
You can list the files being used by systemd for the socket by using:
$ systemctl cat httpd.socket
and on my system this shows (some lines removed to keep it short):
# /usr/lib/systemd/system/httpd....
- 1,563
4
votes
CentOS 8.2 LDAP client configuration
sssd does not support LDAP authentication over unencrypted connections.
From sssd-ldap(5) man page:
If you want to authenticate against an LDAP server either TLS/SSL or LDAPS is required. sssd does ...
- 61
4
votes
x11vnc can not connect to X server of gdm greeter
Run x11vnc as gdm user:
sudo -u gdm x11vnc -rfbauth /etc/vncpasswd -auth /run/user/42/gdm/Xauthority -display :0
- 41
3
votes
Accepted
Infected server (bitcoin mining malware)
It sounds to me that this process was already running (ie in memory) when you did your cleanup and you didn't kill it, so its still there.
The 990 username means the user no longer exists. It ...
- 6,117
3
votes
How can I enable epel-release before installing packages with cloud-init?
Add this to your cloud init script:
yum_repos:
epel-release:
baseurl: http://download.fedoraproject.org/pub/epel/7/$basearch
enabled: true
failovermethod: priority
...
- 11k
3
votes
Creating a bridged WiFi AP (hotspot) in Centos 8 (or Fedora)
NetworkManager / nmcli CAN create access points that are part of a bridge. WPA supplicant seemed
to have a problem figuring out the type of interface after bridging, however that was resolved by ...
- 158
3
votes
Yum on Centos 8 - Failed to download metadata for repo 'AppStream'
You need to be connected to the Internet in order to download packages.
Check that you have an IP address (with ip a), that you have a default route (with ip r), and that you have nameservers defined ...
- 242k
3
votes
Yum on Centos 8 - Failed to download metadata for repo 'AppStream'
In the name of ALLAH.
I think that This problem reseon is for End of Life of centos version..
CentOS Linux 7 EOL: 2024-06-30
CentOS Linux 8 EOL: 2021-12-31
CentOS Stream 8 EOL: 2024-05-31
CentOS ...
3
votes
Accepted
How to modify a VM instance setting to boot from BIOS to UEFI?
This is an old post, but I was able to resolve this issue. All I did was create the new smaller drive from the same public bootable image as the original drive. (in my case Ubuntu 18.04 LTS: ubuntu-...
- 46
Only top scored, non community-wiki answers of a minimum length are eligible