The DNS servers in Raspberry Pi are listed in /etc/resolv.conf file. If you want to change the Raspberry Pi’s DNS server settings you shouldn’t update this file manually, because all changes will be overwritten after reboot by data that your local DHCP server provides. In this note i will show how to change DNS servers […]
MongoDB stores data records as documents which are gathered together in collections. Databases in MongoDB hold one or more collections of documents. In this short note i will show how to list all collections of a database in MongoDB from the command-line using the mongo shell.
MongoDB is a powerful open-source NoSQL databases, that is commonly used in the modern web applications. The databases in MongoDB can be listed from the command-line using the mongo shell and in this short note i will show how to do this.
RabbitMQ is a message-queueing software also known as a message broker or queue manager. Queue in RabbitMQ is the buffer that stores messages, while message is the information that is sent from the producer to a consumer through RabbitMQ. In this note i will show how to list queues in RabbitMQ from the command-line using […]
The internal RabbitMQ users can be managed from the command-line using the rabbitmqctl command. Note, that the users from any alternative authentication backends (e.g. LDAP) cannot be inspected or managed with the commands listed below. In this note i will show how to list, create, set permissions and delete internal RabbitMQ users from the command-line […]
Virtual hosts or vHosts in RabbitMQ allow to segregate applications using the same RabbitMQ instance by providing logical grouping and separation of resources. If you are familiar with virtual hosts in Apache or server blocks in Nginx, the idea is similar. In this note i will show how to list, create and delete virtual hosts […]
If you have forgotten the Jenkins admin password and can’t log in to a Jenkins user interface (UI) as administrator, you can connect to a Jenkins server via SSH and reset the Jenkins admin password. The simplest solution is to completely disable security in /var/lib/jenkins/config.xml file, access the Jenkins UI omitting authentication and rest the […]
The first time you start Jenkins, the configuration is created along with the initial default administrator account. If for some reason you have skipped the user-creation step in the setup wizard, you can use the default admin username and password to access the Jenkins UI. The Jenkins default password is stored in the $JENKINS_HOME/secrets/initialAdminPassword file […]
To checkout a remote branch in Git, first of all it is required to figure out what branches exist on a remote Git repository. By default, the git branch command lists the local branches only. In this short note i’ll show how to list only remote branches in Git and also how to list all […]
“You are in ‘detached HEAD’ state” is not an error message and is nothing to be worried about. This state means you are no longer on a branch, and it happens when an arbitrary commit is checked out instead of a branch. If this state was unintentional and you want to “fix” the ‘detached HEAD’, […]