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DH Unlimited is comprised solely of me, Dave. I've been doing freelance web development since 2010, mainly for the purpose of expanding my technical skill set.

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Happy SysAdmin Day!

Friday, July 31, 2015 9:54 am


Tag(s): Windows  Work  Linux 

Apache Client Certificate Authentication

Thursday, July 16, 2015 11:21 am

Below is a useful link for implementing authentication using client certificates and Apache.

Tag(s): Web Programming  Work  Linux 

PostgreSQL Current Process List

Wednesday, May 20, 2015 4:26 pm

To kill a process:
    — don’t kill my own connection!
    procpid <> pg_backend_pid()
    — don’t kill the connections to other databases
    AND datname = ‘database_name’;
Or you can just leave off the FROM clause
SELECT pg_terminate_backend(procpid);

To view process details:
SELECT datname, procpid, current_query FROM pg_stat_activity;

Tag(s): PostgreSQL 

CompTIA Frames

Wednesday, April 29, 2015 9:49 am

Why can’t CompTIA reward their certification holders with a certificate that is a normal size? What’s up with the 8.5” x 5.5” dimensions??


Tag(s): CompTIA 

Linux Authentication Without a Password

Friday, April 17, 2015 2:29 pm

Steps to generate SSH keys on a client machine and transfer to a remote server for authentication:

On Remote Server:
Turn PasswordAuthentication off in /etc/ssh/sshd_config
Restart SSHD Service

On Client Server:
[username@localhost ~]$ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/home/username/.ssh/id_rsa):
Created directory ‘/home/username/.ssh’.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/username/.ssh/id_rsa.
Your public key has been saved in /home/username/.ssh/id_rsa.pub.
The key fingerprint is:
91:12:3b:12:24:re:0b:w1:e2:fe:ce:33:fa:b8:99:ed username@localhost.localdomain
The key’s randomart image is:
—[ RSA 2048]—— | . . .. | |..oo | |
[username@localhost ~]$ cd /home/username/.ssh/
[username@localhost .ssh]$ cp id_rsa.pub authorized_keys
[username@localhost .ssh]$ chmod 700 /home/username/.ssh
[username@localhost .ssh]$ chmod 600 /home/username/.ssh/authorized_keys
[username@localhost .ssh]$ ssh-copy-id user@domain.com
The authenticity of host ‘dommain.com (’ can’t be established.
RSA key fingerprint is 00:c9:00:be.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed — if you are prompted now it is to install the new keys
user@domain.com’s password:

Number of key(s) added: 1

Now try logging into the machine, with: “ssh ‘user@domain.com’”
and check to make sure that only the key(s) you wanted were added.

Tag(s): Linux 
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