PROBLEM: After 2nd factor activation on Gitlab, username and password auth is not working anymore SOLUTION: Generate API key and use modified url Generate your API key on Gitlab You can find this option in Preferences > Access Tokens Copy this token and note you will see it only once (you have to generate a new one if the old is lost) Create new URL
|
1 |
So if you would like to push or clone the repo using e.g. git…
Git basics Simple instruction how to handle git on the command line Check if Git is installed and ready
|
1 |
git --version |
If not, you can install git using (on Ubuntu)
|
1 |
sudo apt install git |
Set username and email Every commit is marked with username and email to identify the autor
|
1 2 |
git config --global user.name "YOUR_USERNAME" |
You can check the informations using
|
1 |
git config --global --list |
(1) Initialize a local directory for Git If you want to include your local directory to version control, use init to tell Git what to track…
PROBLEM: I cannot open some folders or use them properly. SOLUTION: Change ownership of the file. For single files
|
1 |
chown username filename |
For directory
|
1 |
chown -R username directory/ |
For changing owner and group
|
1 |
chown username:group file |
or
|
1 |
chown -R username:group directory/ |
PROBLEM: I need to change password, but I do not remember the old one. SOLUTION: Simple one line command saves the day!
|
1 |
root:~# sudo passwd $USER |
And yes, you have to be logged as root or be able to use sudo.
PROBLEM: I would like to backup files to the cloud. SOLUTION: Pick Backblaze B2 with awesome pricing. 1.0 Create Application Key Using official guide – https://help.backblaze.com/…Account-ID-and-Application-Key Backblaze has a very easy and intuitive interface, so I bet you don’t need any guide to do it 🙂 2.0 Connection String
|
1 |
b2://[account id]:[application key]@[B2 bucket name] |
You should substitute real keys with variables, just to make the string more flexible. E.g.:
|
1 2 3 4 |
export ACC_ID="00011112223aaa" export APP_KEY="AAABBBCCCDDD000" b2://$account_ID:$application_key@my-fav-bucket/folder/ |
3.0 – Duplicity 3.1 Backup Using Duplicity to Backblaze is very simple! You just need to generate…
PROBLEM: Need to keep keys to be able restore backups later. SOLUTION: Simple export keys and save where you want to. 1.0 – Export Use gpg –list-keys to show all keys
|
1 |
user@server:~# gpg --list-keys |
|
1 2 3 4 5 |
/user/.gnupg/pubring.kbx ------------------------ pub rsa3072 2019-01-15 [SC] [expires: 2021-01-14] uid [ultimate] myFavKey sub rsa3072 2019-01-15 [E] [expires: 2021-01-14] |
My only key is myFavKey, so I will export this one using
|
1 2 |
user@server:~# gpg --output mykey_pub.gpg --armor --export myFavKey user@server:~# gpg --output mykey_sec.gpg --armor --export-secret-key myFavKey |
And there you go! Yyou should both files export to same safe place 🙂 2.0 – Import Copy both files to server where you would like to restore files and import both keys.
|
1 2 |
user@another-server:~# gpg --import ~/mykey_pub.gpg user@another-server:~# gpg --allow-secret-key-import --import ~/mykey_sec.gpg |
And…
PROBLEM: I would like to change root password on a fresh new install. SOLUTION: Simple one command! Run command below to switch to root:
|
1 |
user@server:~# sudo -i |
Change password by typing:
|
1 |
root@server:~# passwd |
And type new root password. Done!
PROBLEM: I do not need swap. SOLUTION: One command swap disable. [?] What is swap? https://www.linux.com/news/all-about-linux-swap-space Run:
|
1 |
root@server:~# swapoff -a |
And remove swap entry from fstab (the second line only!) And reboot the system.
PROBLEM: SSH is disconnecting after a short time! SOLUTION: Edit SSH server configuration and increase timeout. [?] Boot what? https://www.computerhope.com/jargon/b/boot.htm It is good to reboot the machine and run these 3 commands to understand what is happening during boot and how fast it was. This will show kernel and userspace boot start time.
|
1 |
root@server:~# systemd-analyze |
OUTPUT:
|
1 2 |
Startup finished in <strong>3.972s</strong> (kernel) + <strong>9.259s</strong> (userspace) = <strong>13.232s</strong> graphical.target reached after 7.717s in userspace |
Show services startup order:
|
1 |
root@server:~# systemd-analyze blame |
And to show very detailed report run:
|
1 |
root@server:~# dmesg |
And now you should determine what is slowing down your boot!
PROBLEM: I would like to see how fast is boot of my machine! SOLUTION: No problem! [?] What is SSH? https://www.youtube.com/watch?v=X9jAjG3PWPo By adjusting SSH timeout we can achieve a balance between security (if you forget to close your SSH client) and irritating interruption of your work. You can adjust configure your client or server. I prefer to do this on the server, because you don’t have to do this on every client for every user. Just edit SSH deamon config…