sabato, settembre 08, 2018

Git Hooks - A way to automate deploy tasks

During my work I use git for automate the deploy on production system. Sometimes I need execute some command or script immediately after checkout. Git has a very powerful mechanism called hooks (you can read more about it on official documentation follow this link).
On client side to install hooks what you have to do is to create a dir called hooks under .git/ . But  you do not have to do any of this because when you have initialized your project git create it for you.
If you list the content of hooks dir you can found a list of samples script to use (all of them are bash scripts). Most of this script start with the prefix  pre- or post- followed by action name.
The script that I found helpful is post-checkout that is automatically executed after a successful git checkout. My post-checkout script contain commands for adjust permissions on files and ask to restart web server.

#!/bin/bash
git ls-files -z --with-tree="$2" --directory | xargs -0 chmod o-rxw --
git ls-files -z --with-tree="$2" --directory | xargs -0 chown www-data:www-data --
find . -type d | xargs -I {} chown www-data:www-data {}
find . -type d | xargs -I {} chmod o-rwx {}
exec < /dev/tty

while true;
   do
      read -p "Do you want to restart apache?  [Y/N]:" choice
      case "$choice" in
         y|Y) service apache2 restart;break;;
         n|N) break;;
         *) echo "invalid" && break;;
      esac
   done

Remember to add execute permission to this script or git won't execute it after the checkout.

venerdì, marzo 16, 2018

Git Handbook

How to setup git with SSH Key

# git remote set-url origin [email protected]:<Username>/<Project>.git

Windows CRLF chars.

Su windows bisogna disattivare questa funziona altrimenti non funzionano i caratteri CRLF.
# git config core.autocrlf false

How can I debug git/git-shell related problems?

If you have problem with Git and you need to debug you can run this:

# GIT_CURL_VERBOSE=1 GIT_TRACE=1 git pull
Ref: https://stackoverflow.com/questions/6178401/how-can-i-debug-git-git-shell-related-problems

How to get list of files between change log ?

If you need to get list of files (included directory tree) from change list you can use:

# git diff-tree -r --name-only 2c636a^ 5b47402 | xargs -I {} rsync -aR {} output/

Delete files from git index when they are already deleted


# git ls-files --deleted -z | xargs -0 git rm


How do I show my global git config?

# git config --list

Show remote branches

# git branch -vr

Filename too long in git for windows


git config --system core.longpaths true

Note: You need to run as administrator.

Ref: https://stackoverflow.com/questions/22575662/filename-too-long-in-git-for-windows



List log with tag date


git log --date-order --graph --tags --simplify-by-decoration --pretty=format:'%ai %h %d'

venerdì, marzo 02, 2018

How to improve reading of log files

There are hard times when a sysadmin have to read a lot of rows of log files for troubleshoot a system error. In this times can be helpful to use some tools to improve reading of these files.

I've found two tools:

  • Generic Colouriser (GRC)https://github.com/garabik/grc - there are programs: grc and grcat. The main is grcat, which acts as a filter, i.e. taking standard input, colourising it and writing to standard output. Then you can use configuration files for customize color ouput depend on you application output log. 
  • Log File Navigator (LNAV)http://lnav.org/ - this is a real log file navigator that parse content of file and follow the stream for read latest lines. Lnav can help highlight the parts that are important and filter out the noise.