openvpn pam_google_authenticator.so error in centos 7

This is the short story: I was trying to implement google OTP authentication while connecting to openvpn, so that in addition to normal password you need to pass timed token generated by your mobile app. My OS was CentOS 7.

The problem was that it didn't work after following some instruction on the web. (like this one http://dillidba.blogspot.com/2017/02/install-openvpn-on-centos-with-google.html)

My openvpn log was showing this error:

Centos 7: uwsgi.sock failed (13: Permission denied) while connecting to upstream. How to fix.

In centos i had this issue in my nginx error.log:

uwsgi.sock failed (13: Permission denied) while connecting to upstream, client: ...

After searching a bit, I found that this is because of centos SELinux permissions.

linux command to extract .gz, .tar.bz2, .tar.gz files

I always forget how to decompress/extract certain file types in linux. Below I publish list of linux commands to decompress different archives:

Linux extract commands

.gz:

gunzip filename.gz

coommand will delete original file after extraction

.bz2:

bzip2 -d filename.bz2

coommand will delete original file after extraction

bzip2 -dk filename.bz2

this command also extracts but keep original

.tar.gz

tar -xvzf filename.tar.gz

• x: tar can collect files or extract them. x does the latter.
• v: makes tar talk a lot. Verbose output shows you all the files being extracted.
• z: tells tar to decompress the archive using gzip
• f: this must be the last flag of the command, and the tar file must be immediately after. It tells tar the name and path of the compressed file.