Why is ssh agent forwarding not working?
It turns out my key was not in the agent, and this fixed it: OS X: ssh-add -K Linux/Unix: ssh-add -k You can list loaded keys using: ssh-add -l ssh-add -L # for more detail
ubuntu
Best location to keep SSL certificates and private keys on Ubuntu servers?
The .crt file is sent to everything that connects; it is public. (chown root:root and chmod 644) To add to the private key location; make sure you secure it properly as well as having it in there. (chown root:ssl-cert and chmod 640)
Automate the installation of postfix on Ubuntu
You can use pre-seeding for this, using the debconf-set-selections command to pre-answer the questions asked by debconf before installing the package. For example: debconf-set-selections <<< “postfix postfix/mailname string your.hostname.com” debconf-set-selections <<< “postfix postfix/main_mailer_type string ‘Internet Site'” apt-get install –assume-yes postfix
Amazon Linux vs. Ubuntu for Amazon EC2 [closed]
I was in a similar situation; fully managed dedicated server, LAMP, CentOS. Then we decided to move to EC2. Also, I had very little systems or linux administration experience. I have almost zero experience with Ubuntu, so I really cannot speak to which is the so-called better OS. I tried a bunch of pre-built AMI’s … Read more
How does Ubuntu keep track of the “System restart required” flag in motd?
Check for the presence of /var/run/reboot-required.
How can I edit the welcome message when ssh start?
You need to edit two files: /etc/motd (Message of the Day) /etc/ssh/sshd_config: Change the setting PrintLastLog to “no”, this will disable the “Last login” message. And then restart your sshd.
dpkg-reconfigure: unable to re-open stdin: No file or directory
I got the error message to go away by putting the following in my provisioning script, prior to any apt-get calls: export DEBIAN_FRONTEND=noninteractive This makes debconf use a frontend that expects no interactive input at all, preventing it from even trying to access stdin.
list all packages from a repository in ubuntu / debian
Simple: grep -h -P -o “^Package: \K.*” /var/lib/apt/lists/ppa.launchpad.net_*_Packages | sort -u Or more flexible: grep-dctrl -sPackage . /var/lib/apt/lists/ppa.launchpad.net_*_Packages For fancier querying, use apt-cache policy and aptitude as described here: aptitude search ‘~O LP-PPA-gstreamer-developers’
Which ports do I need to open in the firewall to use NFS?
$ rpcinfo -p | grep nfs Port 111 (TCP and UDP) and 2049 (TCP and UDP) for the NFS server. There are also ports for Cluster and client status (Port 1110 TCP for the former, and 1110 UDP for the latter) as well as a port for the NFS lock manager (Port 4045 TCP and … Read more
CentOS vs. Ubuntu [closed]
There are no benefits that I can discern for using CentOS (or RHEL) over Ubuntu if you are equally familiar with using both OSes. We use RHEL and CentOS heavily at work, and it’s just painful — we’re building custom packages left and right because the OS doesn’t come with them, and paid RedHat support … Read more