Openssl certificates for apache

In my former post i described a way how to create self signed SSL certificates with an own certificate authority. These certificates didn’t work in latest chrome versions so I updated my scripts to create valid certificates for chrome. This time I only create wildcard certificates because creating one for every subdomain was annoying.

I also tried to use these certificates in postfix which did NOT work. To create files for postfix see my former post.

 

Robo 3T MongoDB client fails to start on ubuntu 16.04

I tried to rim robo3t-1.1.1-linux-x86_64 downloaded from https://robomongo.org/ and got the following error when trying to run it:

Trying to install xcb via apt install xcb doesn’t change the behavior. Then I found a solution by removing all libstdc++* files from the lib directory in the extracted directory:

failed to run Kubelet: failed to create kubelet: misconfiguration: kubelet cgroup driver: “systemd” is different from docker cgroup driver: “cgroupfs”

Distributor ID: Ubuntu
Description: Ubuntu 16.04.3 LTS
Release: 16.04
Codename: xenial

Docker version 17.06.0-ce, build 02c1d87

openshift-origin-server-v3.6.0-c4dd4cf-linux-64bit

I followed the steps under https://docs.openshift.org/latest/getting_started/administrators.html#downloading-the-binary and got the error in the title. To fix this you have to add “–exec-opt native.cgroupdriver=systemd” to ExecStart of docker. The best way to do this is to add a addin file /etc/systemd/system/docker.service.d/override.conf with following content:

Then reload systemd and restart docker:

 

Ubuntu: Docker behind proxy

 

error: symbol ‘grub_efi_find_last_device_path’ not found

Updating to the latest grub version leads to “error: symbol ‘grub_efi_find_last_device_path’ not found” on my dual boot system having Ubuntu 15.10 next to Windows 10.

This can be fixed by downgrading to the version before the latest one in the ubuntu repository till this bug is fixed.

Here is how I downgraded my grub installation:

Without the hold line apt would install the latest version on the next upgrade. As soon as the bug is fixed you can remove the hold mark with

hwclock problems with dual boot

My English version of Windows 10 and Ubuntu 16.04 could not agree whether my hwclock is UTC or not. So booting either Window or Linux changed my hwclock and then the time in the other OS was wrong. So I changed my hwclock to UTC and told Windows and Linux that my clock is set to UTC:

Windows:

Linux:

Open the file (as superuser)

and add or change UTC=yes

Ubuntu 15.10 “error: symbol ‘grub_efi_find_last_device_path”

Updating to the latest grub version (at the moment 2.02~beta2-29ubuntu0.3) leads to “error: symbol ‘grub_efi_find_last_device_path’ not found” when I try to start Windows on my dual boot system having Ubuntu 15.10 next to Windows 10.

This can be fixed by downgrading to the version before the latest one in the ubuntu repository till this bug is fixed.

Here is how I downgraded my grub installation:

Without the hold line apt would install the latest version on the next upgrade. As soon as the bug is fixed you can remove the hold mark with

Disable Guest Session in Ubuntu 15.10

Ubuntu 15.10 is using lightdm desktop manager. man lightdm says that it is using /etc/lightdm/lightdm.conf for configuration. Ubuntu 15.10 does not include such a file. To disable the guest session create the file (/etc/lightdm/lightdm.conf) with following content:

 

Install Docker in Ubuntu 12.04 Precise

First make sure you have the latest version and an actual kernel running. Execute theses commands as root:

Then install docker with the following lines as root:

After this docker should be up and running. Rry using “docker ps” as root or with sudo.

Disable guest account in ubuntu 14.10

To disable the guest account simply change the file /usr/share/lightdm/lightdm.conf.d/50-guest-wrapper.conf and add the last line:

Don’t forget that you have to restart lightdm before changes take effect.