slaskdot

Graphing DNS queries with bindgraph

2013-08-22T11:56:52+02:00

Bindgraph is a tool that allow us to make graphs over queries resolved by our DNS servers.

To be able to use bindgraph, we need to configure bind to store its queries in a log file that bindgraph can read.

Installing bindgraph

# apt-get install bindgraph

Enabling logging in bind9

Add the following line in /etc/bind/named.conf, right after the other includes.

include "/etc/bind/named.conf.log";

In /etc/bind/named.conf.log add the following configuration:

logging {
  category security { security_channel; default; };
  category lame-servers { null; };
  category default { default; };
  category queries { querylog; };

  channel security_channel {
    file            "/var/log/named/security.log";
    severity        debug;
    print-time      yes;
    print-category  yes;
    print-severity  yes;
  };

  channel default {
    file            "/var/log/named/bind.log" versions 3 size 5m;
    severity        warning;
    print-time      yes;
    print-category  yes;
    print-severity  yes;
  };

  channel "querylog" {
    file            "/var/log/named/bind-queries.log";
    print-time      yes;
    print-category  yes;
  };
};

Now we have enabled logging in bind9, but we also need to create the folder its going to write its log files to and set the right permissions.

# mkdir /var/log/named
# chown bind:bind /var/log/named/

Configuring bindgraph

In /etc/default/bindgraph edit the line starting with DNS_LOG so that it points to the correct log file.

DNS_LOG=/var/log/named/bind-queries.log

Last thing we need to do, is to restart bind9 and bindgraph services.

# service bind9 restart
# service bindgraph restart

Viewing the graphs

To be able to see the graphs, bindgraph has a CGI front end, so we need an web server that can show us the graphs, I’m using Apache for this.

Just install Apache with apt-get install apache2 and point your web browser to <FQDN-of-dns-server/cgi-bin/bindgraph.cgi>.

Graphing DNS queries with bindgraph was originally published by John Johannessen at slaskdot on August 22, 2013.

How to open a port range in ufw

2013-08-20T12:46:52+02:00

I’m a big user of Mosh when I’m out and about. Mosh uses UDP ports to connect back to the server, and this port range needs to be open on the server. By default Mosh uses the first available UDP port, starting at 60001 and stopping at 60999.

ufw allow proto udp to any port 60001:60999

I use ufw on my servers, as an easy front end to iptables.

How to open a port range in ufw was originally published by John Johannessen at slaskdot on August 20, 2013.

Getting real IP addresses using CloudFlare and Nginx

2013-08-20T01:21:26+02:00

Before you start

Before you start, you have to check if your nginx have been compiled with --with-http_realip_module, you do that by running the command nginx -V and look for the module.

# nginx -V
nginx version: nginx/1.2.1
TLS SNI support enabled
configure arguments: --prefix=/etc/nginx --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-client-body-temp-path=/var/lib/nginx/body --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --http-log-path=/var/log/nginx/access.log --http-proxy-temp-path=/var/lib/nginx/proxy --http-scgi-temp-path=/var/lib/nginx/scgi --http-uwsgi-temp-path=/var/lib/nginx/uwsgi --lock-path=/var/lock/nginx.lock --pid-path=/var/run/nginx.pid --with-pcre-jit --with-debug --with-http_addition_module --with-http_dav_module --with-http_geoip_module --with-http_gzip_static_module --with-http_image_filter_module --with-http_realip_module --with-http_stub_status_module --with-http_ssl_module --with-http_sub_module --with-http_xslt_module --with-ipv6 --with-sha1=/usr/include/openssl --with-md5=/usr/include/openssl --with-mail --with-mail_ssl_module --add-module=/tmp/buildd/nginx-1.2.1/debian/modules/nginx-auth-pam --add-module=/tmp/buildd/nginx-1.2.1/debian/modules/nginx-echo --add-module=/tmp/buildd/nginx-1.2.1/debian/modules/nginx-upstream-fair --add-module=/tmp/buildd/nginx-1.2.1/debian/modules/nginx-dav-ext-module

This is my output from an standard Debian installed nginx package.

Nginx configuration

The documentation for HttpRealipModule module states that the configuration should be in either http, server or location context. You probably want to add these server wide, in /etc/nginx/nginx.conf. But this file is likely to be overwritten by an update, so I recommend to make a cloudflare.conffile in /etc/nginx/conf.d.

Content of /etc/nginx/conf.d/cloudflare.conf

set_real_ip_from   204.93.240.0/24;
set_real_ip_from   204.93.177.0/24;
set_real_ip_from   199.27.128.0/21;
set_real_ip_from   173.245.48.0/20;
set_real_ip_from   103.21.244.0/22;
set_real_ip_from   103.22.200.0/22;
set_real_ip_from   103.31.4.0/22;
set_real_ip_from   141.101.64.0/18;
set_real_ip_from   108.162.192.0/18;
set_real_ip_from   190.93.240.0/20;
set_real_ip_from   188.114.96.0/20;
set_real_ip_from   197.234.240.0/22;
set_real_ip_from   198.41.128.0/17;
set_real_ip_from   162.158.0.0/15;
set_real_ip_from   2400:cb00::/32;
set_real_ip_from   2606:4700::/32;
set_real_ip_from   2803:f800::/32;
set_real_ip_from   2405:b500::/32;
set_real_ip_from   2405:8100::/32;
real_ip_header     CF-Connecting-IP;

CloudFlare do change their IPs from time to time (they keep an updated list online), and since we have the list of IPs in an separate file, its easy to automate an update of these.

An update script would look something like this:

#! /bin/bash
#
# Update cloudflare.conf with new IPs
#

cloudFlareConf="/etc/nginx/conf.d/cloudflare.conf"
IPV4=$(curl -s "https://www.cloudflare.com/ips-v4")
IPV6=$(curl -s "https://www.cloudflare.com/ips-v6")
DATE="$(date)"

echo "# Last updated ${DATE}" > ${cloudFlareConf}

for IPV4ip in ${IPV4}
do 
  echo "set_real_ip_from ${IPV4ip};" >> ${cloudFlareConf}
done

for IPV6ip in ${IPV6}
do
  echo "set_real_ip_from ${IPV6ip};" >> ${cloudFlareConf}
done

echo "real_ip_header CF-Connecting-IP;" >> ${cloudFlareConf}

Getting real IP addresses using CloudFlare and Nginx was originally published by John Johannessen at slaskdot on August 20, 2013.

HP Array Configuration Utility CLI for Linux

2013-08-19T02:48:48+02:00

HP Array Configuration Utility CLI for Linux (hpacucli) is a program for controlling HP Smart Array controllers.

To invoke the interactive shell, run the command hpacucli. for help run hpacucli help.

Controller Commands

Display detail of Controller

hpacucli> ctrl all show config
hpacucli> ctrl all show config detail

Display status of Controller

hpacucli> ctrl all show status

Enable or Disable the cache

hpacucli> ctrl slot=0 modify dwc=disable
hpacucli> ctrl slot=0 modify dwc=enable

Detects newly added devices since the last rescan

hpacucli> rescan

Physical Drive Commands

Display detail information of physicalDrive

hpacucli> ctrl slot=0 pd all show
hpacucli> ctrl slot=0 pd 2:3 show detail

Display Status of physicalDrive

hpacucli> ctrl slot=0 pd all show status
hpacucli> ctrl slot=0 pd 2:3 show status

To Erase the physicalDrive

hpacucli> ctrl slot=0 pd 2:3 modify erase

To enable or Disable the LED

hpacucli> ctrl slot=0 pd 2:3 modify led=on
hpacucli> ctrl slot=0 pd 2:3 modify led=off

Logical Drive Commands

Display detail information of LogicalDrive

hpacucli> ctrl slot=0 ld all show
hpacucli> ctrl slot=0 ld 4 show

Display Status of LogicalDrive

hpacucli> ctrl slot=0 ld all show status
hpacucli> ctrl slot=0 ld 4 show status

To re-enabling failed drive

hpacucli> ctrl slot=0 ld 4 modify reenable forced

Create LogicalDrive with RAID 0 using one drive:

hpacucli> ctrl slot=0 create type=ld drives=1:12 raid=0

Create LogicalDrive with RAID 1 using two drives:

hpacucli> ctrl slot=0 create type=ld drives=1:13,1:14 size=300 raid=1

Create LogicalDrive with RAID 5 using five drives:

hpacucli> ctrl slot=0 create type=ld drives=1:13,1:14,1:15,1:16,1:17 raid=5

To Delete LogicalDrives

hpacucli> ctrl slot=0 ld 4 delete

Expanding logicaldrive by adding one more drive

hpacucli> ctrl slot=0 ld 4 add drives=2:3

Extending the LogicalDrives

hpacucli> ctrl slot=0 ld 4 modify size=500 forced

Add two Spare disks

hpacucli> ctrl slot=0 array all add spares=1:5,1:7

HP Array Configuration Utility CLI for Linux was originally published by John Johannessen at slaskdot on August 19, 2013.

Clear cache on Bind9

2013-08-11T21:34:34+02:00

Its simple as:

rndc flush

Clear cache on Bind9 was originally published by John Johannessen at slaskdot on August 11, 2013.

Youtube Test

2013-07-28T06:06:06+02:00

Just testing a jekyll plugin for youtube videoes.

Youtube Test was originally published by John Johannessen at slaskdot on July 28, 2013.

Command Line Tools in Mavericks (Mac OS X 10.9)

2013-07-08T01:10:56+02:00

Things have changed

In previes releases of Xcode, you went into Preferences and then to the Downloads tab, and choose to download and install Command Line Tools. In Xcode 5 this have changed. It have been removed, and a new way is intodused. The best part of the new way, is that you don’t even have to install Xcode 5 to get Command Line Tools anymore.

The new way

Open up an terminal (Terminal.app or iTerm2.app)
Enter the following command xcode-select --install. This will start a wizard that will help you install Command Line Tools in your installation of Mavericks.
Click on “install” to start the installation wizzard.
Agree to the License Agreement
The Installation will ask you for admin rights and start the installation.
After the installation is complete, you have Command Line Tools installed.

Command Line Tools in Mavericks (Mac OS X 10.9) was originally published by John Johannessen at slaskdot on July 08, 2013.

Homebrew Cask

2013-07-07T06:24:24+02:00

Homebrew is an package manager for OSX, that lets you easily install software that Apple did not ship with OSX. Homebrew Cask is an extension to Homebrew, to install and keep control over Mac applications distributed as binaries.

Installation

Open an terminal (Terminal.app or iTerm2.app) and type in the following commands.

# brew tap phinze/homebrew-cask
# brew install brew-cask

When they have run, you should have Homebrew Cask installed on your system.

Usage

List installable packages

# brew cask search

Install package

# brew cask install google-chrome

List installed packages

# brew cask list

Remove installed packages

# brew cask uninstall

The applications that I use.

# brew cask install alfred
# brew cask install cord
# brew cask install dropbox
# brew cask install evernote
# brew cask install f-lux
# brew cask install firefox
# brew cask install google-chrome
# brew cask install istat-menus
# brew cask install iterm2
# brew cask install the-unarchiver
# brew cask install totalspaces
# brew cask install tower
# brew cask install transmit
# brew cask install one-password
# brew cask install spotify
# brew cask install vlc
# brew cask install sublime-text

Homebrew Cask was originally published by John Johannessen at slaskdot on July 07, 2013.