The Problem A regular user is not able list images using docker images command. Following error can be observed. user01> docker images Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get http://%2Fvar%2Frun%2Fdocker.sock/v1.27/images/json: dial unix /var/run/docker.sock: connect: permission denied The Solution User is not part of docker group and doesn't have permissions to execute docker related commands. Add regular user to … [Read more...] about ‘docker images’ command error – “Permission Denied”
Linux
How to change the interface name in CentOS/RHEL 8 using prefixdevname
This post will help to change the network interface name using prefixdevname utility in CentOS/RHEL 8 systems. Installation and configuration 1. Install the required package using dnf utility: # dnf install prefixdevname 2. Append the net.ifnames.prefix=[ABCD] using grubby command: (ABCD to replaced with own prefix, eg: net). # grubby --update-kernel=$(grubby --default-kernel) --args="net.ifnames.prefix=net" 3. Reboot the system to take effect: # reboot 4. After system rebooted, … [Read more...] about How to change the interface name in CentOS/RHEL 8 using prefixdevname
How to configure EPEL repository in OEL 7
Question: How to install/get packages from EPEL Repository on OEL 7? 1. Create a repo file like /etc/yum/repos.d/epel-yum-ol7.repo. For example: # cat /etc/yum.repos.d/epel-yum-ol7.repo [ol7_epel] name=Oracle Linux $releasever EPEL ($basearch) baseurl=http://yum.oracle.com/repo/OracleLinux/OL7/developer_EPEL/$basearch/ gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-oracle gpgcheck=1 enabled=1 2. And then run "yum repolist" command to see if repository is in there. # yum … [Read more...] about How to configure EPEL repository in OEL 7
How to re-create the yum cache (force a fetch of the cache data) from enabled repositories in CentOS/RHEL
This post briefly outlines how it possible to re-create the yum cache, or said in another way, force a fetch of the cache data from the enabled yum repositories. The enabled yum repositories are the ones in the following file /etc/yum.conf or in the following folder /etc/yum.repos.d that have their "enabled" setting to "1", e.g. : # vi /etc/yum.repos.d/test.repo [test_repo] name=Test … [Read more...] about How to re-create the yum cache (force a fetch of the cache data) from enabled repositories in CentOS/RHEL
How to Create yum Repository in CentOS/RHEL
1. Create a directory for you local repository, e.g. /home/mypackage_dir/repository. Move the RPMs into that directory. # mkdir /home/mypackage_dir/repository # cp /media/packages/* /home/mypackage_dir/repo 2. Fix some ownership and filesystem permissions: # chown -R root:root /home/mypackage_dir/repo 3. Install the createrepo package if not installed yet, and run: # createrepo /home/mypackage_dir/repo # chmod -R o-w+r /home/mypackage_dir/repo 4. Create a repository configuration … [Read more...] about How to Create yum Repository in CentOS/RHEL
How to Disable Client Access Control in MySQL
You can disable the client access control in MySQL by telling the server not to read the grant tables and disable access control. Use the --skip-grant-tables option to do so. The --skip-grant-tables option has the following effects: When connected, the user has full privileges to do anything. This option disables account management statements such as CREATE USER, GRANT, REVOKE, and SET PASSWORD. Disabling access control is convenient if you forget the root password and need to reset it … [Read more...] about How to Disable Client Access Control in MySQL
How to Disable NetworkManager in CentOS/RHEL 8
Although NetworkManager is the default tool for configuring and managing the network services on CentOS/RHEL 8, there are situations where it may be necessary to permanently disable NetworkManager, and use alternative methods to configure and manage the network. This document describes how to permanently disable NetworkManager on CentOS/RHEL 8. Note: Use of "networks-scripts" is deprecated in CentOS/RHEL 8. Disabling NetworkManager in CentOS/RHEL 8 1. The following three commands are … [Read more...] about How to Disable NetworkManager in CentOS/RHEL 8
How to Disable Docker Process and docker0 Interface on CentOS/RHEL
When the docker packages are installed, the services and related docker0 network interface are enabled. In some cases, you may want to disable the docker service and the docker0 network interface as well. This post details how to disable Docker and the docker0 interface if it is not required or if the docker0 interface is conflicting with other network interfaces/routes. 1. Ensure the Docker service is stopped: # service docker stop # for CentOS/RHEL 6 # systemctl stop docker # … [Read more...] about How to Disable Docker Process and docker0 Interface on CentOS/RHEL
What is the purpose of “system user” in MySQL Replication
This post focusses on understanding why the "system user" is seen in SHOW PROCESSLIST and the information_schema.PROCESSLIST view on replication slaves. The system user is not a real user and is used for display purposes only to indicate it is the system performing the task. It is used by the I/O and SQL threads (connection and applier threads) on a replication slave. These threads are handled by the system and not by a login user. The system user can for example be seen in the output of … [Read more...] about What is the purpose of “system user” in MySQL Replication
What are Reserved User Accounts in MySQL
The are a few users created by MySQL for various purposes ranging from handling the replication to be the definer for sys schema objects. The users are summarized in the following table: UserFirst VersionLast VersionFeatureComments system user(At least since 5.0) ReplicationUsed for the I/O and SQL threads (connection and applier threads). This is not a real user, but just a label used in SHOW PROCESSLIST and similar places to indicate it is an internal user. There is no way to … [Read more...] about What are Reserved User Accounts in MySQL