Wayne D's Blog

It's been a while. I wanted to refer to my docker cheat sheet and found that my website was broken. I have no idea how long it's been down but I spent the time to get it reconfigured and working again.

The West Wing reunion stage presentation of "Hartsfield's Landing" is now available in Canada on Crave.ca. Not to be missed by any dedicated West Wing fan. https://www.crave.ca/en?ua=eyJtIjoiYSIsInAiOlsiYyIsImNwIl0sImwiOiJlbiJ9#/special/48345

The creative team and cast organized this historic production in order to raise awareness for and support of When We All Vote, a non-profit, nonpartisan organization co-chaired by Michelle Obama.

Microsoft has done a good job of keeping Skype for Linux up to date with one glaring exception. When you install Skype for Linux from the rpm it won't start. If you dig down into the Skype log which is found in ~/.config/skypeforlinux/logs/skype-startup.log on Centos no matter what you might see on the internet You will find the following message

FATAL:setuid_sandbox_host.cc(157)] The SUID sandbox helper binary was found,
but is not configured correctly. Rather than run without sandboxing I'm aborting now.
You need to make sure that /usr/share/skypeforlinux/chrome-sandbox is owned by root
and has mode 4755

running chmod 4755 /usr/share/skypeforlinux/chrome-sandbox as root fixes the problem. Unfortunately every time you update Skype you have to do this again! Since you have to install the rpm as root it should be a simple task to fix this but this problem as existed for quite a while. Come on Microsoft don't be so passive aggressive and fix this up!

Wondering why my Centos 8 system was behaving so badly tonight, being unresponsive to clicks and acting like it was swapping I fired up top. Top showed me that gnome-shell was quite frequently using 100% cpu. The bad behavior of gnome 3 on this machine has become more of an issue as it's the machine I took home from work to use during the Coronavirus lockdown.

I've was never a fan of gnome 3 and the Classic mode just hides all the ugliness behind an old user interface. I have searched Google on and off over the months, waiting for a prebuilt, rpm based Mate to to be available for Centos 8. The first result Google returns is a page that walks you through compiling mate from source. I might have resorted to that but why reinvent the wheely when someone else might have the done the work already. Luckily reddit user https://www.reddit.com/user/stenstorp/ came to the rescue of frustrated Centos 8 by putting up a repo where you can get the rpm's to install Mate on Centos 8.

I followed his instruction at https://copr.fedorainfracloud.org/coprs/stenstorp/MATE/ , rebooted the my machine and in 10 minutes I was using Mate.

Thanks again stenstorp.

If mate isn't your thing he has also ported the minecraft launcher, the budgie desktop and lightdm to Centos. Check out his repo at https://copr.fedorainfracloud.org/coprs/stenstorp/MATE/

A worthwhile read on why you should not be running sshd in your container https://jpetazzo.github.io/2014/06/23/docker-ssh-considered-evil/
Difference between RUN, CMD and ENTRYPOINT http://goinbigdata.com/docker-run-vs-cmd-vs-entrypoint/

Remove stopped containers: docker container prune
Run with volume mapping: docker run -v /outside_path7:/inside_path image_name ( add /bin/bash at the end to override the Dockerfile and add -it )
List all containers: docker container ls -all
List images: docker images
Remove image: docker rmi image_name
Export image as tarfile: docker save -o tarfile.tar image_name
Load exported image: docker load -i image.tar (This command works much better than import as it creates a container as part of the loading)
Update image with changes: docker commit container_name image_name
Update image with Dockerfile: docker build -t image_name .

Dockerfile

FROM image_name
USER run_as_user
WORKDIR /home/user/directory
ENTRYPOINT
CMD run_this_command