Category Archives: Linux Administration
Manage SSH-keys with the SSH-agent
Many webservices generate ssh keys to access their service. With the amount of services the number of SSH keys grows. To avoid dealing with the keys in the command line and the ssh_config(5), you can simply add the ssh-key to the … Continue reading
Create a luks encrypted partition on Linux Mint
Encryption is not only for someone who has something to hide. There are simple concerns like a lost or stolen laptop that justify a full disk encryption. There are only a few steps necessary to create a encrypted partition. In … Continue reading
Configuring vim for dark terminal windows
On CentOS, vim is installed with a default configuration. These defaults might be right for some users but not for everyone. I will describe the two settings I personally find most annoying for my setup. One of the assumtions in the … Continue reading
Modify file and directory date
Sometimes it is necessary to change a file or even a directory’s timestamp. This sounds easy, but most GUI utilities installed out of the box on OS X as well as on Linux don’t let you change a file’s timestamp. … Continue reading
Shrink sparse cqow2 disc image
There might be cases when a VM temporarily used a lot of disk space which is then not needed any more. The sparse disk image format qcow2 will grow as the disk space is used, but it does not automatically shrink. … Continue reading
Perform a portscan using netcat
To perform a port scan, most of the time we think about a separate program. Sometimes it is not necessary to look that far. On most Linux systems netcat is already installed or can be installed easily from a repository. Continue reading
Restrict SSH access to port forwarding to one specific port
Allowing access to an unprotected service on a server is always a problem. Sometimes the easiest way is to not expose this service to the network but allow access via ssh port-forwarding, but how to limit the SSH account to … Continue reading
Generate public SSH key from private SSH key
A lost SSH public-key or a web service generates an SSH key but does not provide the public-key part to you. What to do now? There is a solution for this situation. Continue reading
Managing shell commands and processes
Not every command you might execute only runs for a couple of seconds. When you have a long running command a couple of problems can come with it. When the ssh connection is not stable, the command might be interrupted, … Continue reading
Setup gitolite to manage git repositories
Git provides all the required tools to create remote repositories. As explained in Setup gitosis to manage git repositories, a bare repository can be generated and managed manually or with gitosis, but this is not the only git repository management … Continue reading
