Ubuntu Hacks

May 12, 2021

This is a collection of hacks and commands for solving basic but painful issues in Ubuntu.

apt-get/apt stuck at 0 OR stalled install/update

Sometimes you run into stuck installs in ubuntu. This could be a result of DNS, Network etc. issues. I have found these to work always. Updating one or both these files with the entries below should work.

• Update /etc/gai.conf by uncommenting this line

  #precedence ::ffff:0:0/96  100
  to
  precedence ::ffff:0:0/96  100
  

• Update kernel parameters to allow IPv6 via /etc/sysctl.conf

  net.ipv6.conf.all.disable_ipv6 = 1
  net.ipv6.conf.default.disable_ipv6 = 1
  net.ipv6.conf.lo.disable_ipv6 = 1
  

  reload by typing sudo sysctl -p or restart the server.

Lock down Packages

To lock packages and prevent them from being upgraded

sudo apt-mark hold PACKAGE
# Example
sudo apt install -y kubelet=1.20.15-00 kubeadm=1.20.15-00 kubectl=1.20.15-00 containerd
sudo apt-mark hold kubelet kubeadm kubectl

Show Packages on Hold

sudo apt-mark showhold

Remove Package Hold

sudo apt-mark unhold PACKAGE