From time to time, when your operating system (Ubuntu, Linux Mint or similar) tries to install new kernel data you may get the following error message:
The volume “boot” has only 0 bytes disk space remaining.
This error means that the /boot partition is full (in most cases there are some old kernels).
To fix this error it needs to delete the old kernels. (more…)
What is a self-signed SSL certificate? A self-signed certificate is a certificate that is not signed by a trusted authority.
Nevertheless, the self-signed certificate provides the same level of encryption as a $100500 certificate signed by a trusted authority.
In this article i will show how to create a self-signed certificate that can be used for non-production or internal applications. (more…)
If you want to update Nginx configuration or renew SSL certificates, you should reload Nginx to apply modifications.
If you run Nginx inside Docker container you might be curious how to reload it without any downtime or connection interruptions.
The best way to reload Nginx inside Docker container is to run docker container exec command and send reload signal to the Nginx. (more…)
Most Linux distributions use systemd as a system and service manager.
The systemctl is the main command in systemd, used to control services.
In this tutorial i will show how to create a systemd service file that will allow you to control your service using the systemctl command, how to restart systemd without reboot to reload unit files and how to enable your new service.
I will also show and describe the most important systemd service file options with the live examples of the systemd service files. (more…)
virtualenv serves for creating isolated Python environments.
It creates a folder with a copy of Python interpreter and a copy of the pip library which will be used to install other packages in this virtual environment without affecting other projects or system-wide libraries.
virtualenv makes it easier to work on more than one project at a time without introducing conflicts in their dependencies.
From this article you will find out how to install, create, activate and deactivate virtualenv. (more…)
For ones, who want to build and run Docker containers on CentOS-7 – first of all it is required to install Docker itself.
To install the latest version of Docker and to be able to upgrade it easily in future – it is recommended to install Docker from the official repository.
In this guide i will show how to install free Docker CE (Community Edition) on CentOS-7 from the stable official repository, how to verify that it is installed correctly and will show the common post-installation steps to perform. (more…)
What is Pip? pip is a tool for installing and managing Python packages.
As well as Python, pip can be install on various operation systems: Linux, Mac, Windows, etc.
In this post i am showing how to install pip on MacOS and how to install pip on Linux (Ubuntu and CentOS). (more…)
The docker logs command serves for accessing the logs of a container.
In this post i am showing how to check the logs of a Docker container, see the timestamps and how to tail or grep these logs.
I will also show how to find out where the Docker container logs are stored. (more…)
The docker stop command stops running Docker containers.
To stop a container it sends the SIGTERM signal to the main process inside a Docker container requesting it to terminate.
If the main process inside a container is not terminated after a grace period, the docker stop command sends the SIGKILL signal to cause it to terminate immediately.
In this post i am showing an example of how to stop a Docker container and also how to stop all running Docker containers. (more…)
The docker exec command serves for executing commands in running Docker containers.
With this command it is also possible to enter a running Docker container and start a bash session.
In this post i am showing how to enter a Docker container and execute an interactive bash shell inside it. (more…)