snippets

using short server names -- 12.08.2020 %

It use to be when I was trying to ssh into one of my servers I would just: in the shell to get my fzz backwards command search, type ssh, then scroll up and down until I found the correct server. As my number of servers has grown this is no longer manageable because I don’t remember which IPs align with with server. Time for some human readable names.

By adding something like this to your ~/.ssh/config:

Host de1
    HostName vxxxxxxxxxxxxxxxxxxxx.megasrv.de
    User travis

Host de2
    HostName vyyyyyyyyyyyyyyyyyyyymegasrv.de
    User travis

Host de3
    HostName vzzzzzzzzzzzzzzzzzzz.megasrv.de
    User travis

Host nyc1
    HostName 123.123.123.1233
    User travis

sshing becomes as easy as:

$ ssh de2

source – https://www.techrepublic.com/article/how-to-use-per-host-ssh-configuration/

\- [ ssh ]

disable user -- 11.08.2020 %

In this case disabling the user named ubuntu from logging in. This includes logging in via ssh.

$ sudo usermod --expiredate 1 ubuntu

\- [ sysadmin ]

automatic tmux session names -- 13.07.2020 %

This month I ditched XQuartz and am back to using Tmux. One part I found tedious was manually naming sessions. I wrote this little alias help. When run from outside a tux session to creates a new session named after the current directory. Ex when in /users/t.shears/dev/cool-app a session named cool-app is created.

Excerpt from my .zshrc

alias tmux_new="tmux new -s \$(pwd | awk -F "/" '{print \$NF}' | sed 's/\./_/g')"

\- [ tmux ]

file search plus size -- 02.07.2020 %

How big are the fonts in this project? Not sure where they are even. This command finds the files using fd then prints file size.

$ fd woff | xargs du -h
 20K    src/assets/fonts/brandon_text_medium.woff2
 20K    src/assets/fonts/brandon_text_regular.woff2
 20K    src/assets/fonts/chronicle_light.woff2
 20K    src/assets/fonts/chronicle_roman.woff2
4.0K    types/woff
4.0K    types/woff2

\- [ fd, du ]

convert .mkv to .mp4 -- 30.06.2020 %

Before I updated my OBS settings to record to .mp4 files I manually converted .mkv files to .mp4. This shell command does that for every recording in a directory deleting the original.

$ for x in $(ls *.mkv | awk -F "." '{print $1}') ; do ffmpeg -i $x.mkv -c copy $x.mp4 && rm $x.mkv ; sleep 3; done

\- [ ffmpeg ]

wipe a mongo collection -- 29.06.2020 %

Currently I run a shared mongo instance in my k8s cluster used by a bunch of my side projects. Every once in a while I have to manually execute mongo commands this is how I do so.

Manually ssh into the pod:

$ kubectl exec -it shared-mongo-xxxxxxxxxx-xxxxx -- /bin/bash

Then launch the mongo shell and hack away:

$ mongo
> db2 = db.getSiblingDB('coolDB')
coolDB
> db2.getCollectionNames()
[ "coolThings" ]
> db2.coolThings.count()
666
> db2.coolThings.remove({})
WriteResult({ "nRemoved" : 666 })
> db2.coolThings.count()
0

source:

\- [ mongo ]

extending gpg keys -- 22.06.2020 %

Don’t let those keys expire. 🚨

Time to edit some keys:

gpg --edit-key t@travisshears.com
Secret key is available.
sec  rsa2048/D4C2E4DFAB8BABF8
     created: 2018-07-18  expires: 2020-07-17  usage: SC
ssb  rsa2048/25C629D0FECC25B9
     created: 2018-07-18  expires: 2020-07-17  usage: E
ssb  rsa4096/97F7C2B46E6C5D11
     created: 2019-09-28  expires: 2023-09-28  usage: E

select key to change key 1
expire
duration: 1y
repeat until every key is updated

resulting output should be something like:

sec  rsa2048/D4C2E4DFAB8BABF8
     created: 2018-07-18  expires: 2021-06-22  usage: SC
ssb  rsa2048/25C629D0FECC25B9
     created: 2018-07-18  expires: 2021-06-22  usage: E
ssb  rsa4096/97F7C2B46E6C5D11
     created: 2019-09-28  expires: 2021-06-22  usage: E

lastly save and done

source:

https://keithbeattyblog.wordpress.com/2019/05/04/how-to-extend-your-gpg-key/

\- [ gpg ]

moving gpg keys -- 20.06.2020 %

New laptop? Got to move over those GPG keys.

$ cd /tmp && mkdir gpg_export
$ gpg --output gpg_export/main_pub.gpg --armor --export t@travisshears.com
$ gpg --output gpg_export/main_sec.gpg --armor --export-secret-key t@travisshears.com
$ tar cvfz gpg_export.tar.gz ./gpg_export
$ gpg --symmetric ./gpg_export.tar.gz

Then move the encrypted tar to the new computer, with airdrop for example.

To import the keys.

$ gpg --decrypt gpg_export.tar.gz.gpg > gpg_export.tar.gz
$ tar xvfz gpg_export.tar
$ gpg --import gpg_export/main_sec.gpg
$ gpg --import gpg_export/main_pub.gpg

Source:

https://www.debuntu.org/how-to-importexport-gpg-key-pair/

\- [ gpg ]

k8s deployment.yaml env vscode snippet -- 20.06.2020 %

Most of my personal projects are deployed via kubernetes. I write a lot of deployment.yaml files. In order to keep them clean and checked in to version control I keep sensitive env variables in a config maps. Problem is adding values env values to deployment.yaml files is pretty painful. This makes it a little less.

placed in yaml.json 😀 what a file name!

{
	"env var from configmap": {
		"prefix": "env",
		"body": [
			"- name: $1",
			"  valueFrom:",
			"    configMapKeyRef:",
			"      key: $1",
			"      name: configmapname"
		],
		"description": "env varable from config map, remember to replace configmapname with your configmap name"
	}
}

\- [ vscode, kubernetes ]

force push with --lease for safety -- 10.06.2020 %

Just found out, via tweet, from the insightful joshdholtz that there is a safer alternative to git push --force

Time to update my aliases:

alias gs="gst"
-alias gpf="gp --force"
+alias gpf="gp --force-with-lease"
alias gdc="gd --cached"

I use zsh shell’s git plugin that is why you see “gst” for git status and “gp” for git push. Highly recommend it

Source:

stackoverflow

\- [ git ]