Simple script for starting, reloading and stopping nginx.

Simple script for starting, reloading and stopping nginx.

For simple use put it in one of the folders listed when running.

echo $path

The script

#!/bin/bash
binpath=/usr/local/nginx/sbin

if [[ -z $1 ]]
then
$binpath/nginx
action=start
elif [[ $1 == "start" ]]
then
$binpath/nginx
action=start
else
$binpath/nginx -s $1
action=$1
fi

if [[ $? == 0 ]]
then
echo "$action successfull"
else
echo "$action failed"
fi

Then use it the following ways.

nginx
nginx start
nginx reload
nginx stop

A quick howto on mod_security rules.

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This howto does not cover installation of mod_security, it will only cover the finer points about rules and how to write your own custom ones ūüôā
A ModSecurity rule does consist of the following.

Always consult the reference manual when writing rules, it covers everything you need. https://github.com/SpiderLabs/ModSecurity/wiki/Reference-Manual

Directive : Eg. SecRule for rules duh…
Scanfiler : REQUEST_URI or USERAGENT etc. full list here.
Scantarget : For example this can be googlebot when checking for useragent.
Action : What to do if filter fount a hit, Eg. Deny, Pass, Allow, log. It also has to contain a unique ID. full list here.

Some actions and scanfilters have prerequisites to work, and they are mostly documented in reference manual.
To start with you can add the following modsecurity rules in modsec config before including custom rules.

SecDataDir /tmp/sectmp
SecTmpDir /tmp
SecAuditLogDirMode 0777
SecPcreMatchLimit 1500
SecPcreMatchLimitRecursion 1500
SecCollectionTimeout 28800
SecRequestBodyAccess On
SecStreamInBodyInspection On
SecHashEngine On
SecRequestBodyInMemoryLimit 1310720

With this set you can forexample store connection ip adresses for up to 8 hours (28800 sec.) and to make a comparison you can say this is a form of session, which you can store session data upon.
With ModSecurity you can have a rule which store a variable on top of a ip, with this you can for example store how many times in the last 10 minutes someone has visited a page on you webpage.

Lets make an example like that.

First we need to start storing a “Session” for every visiting ip address.
This you can do with ACTION initcol like so.

SecAction phase:1,nolog,pass,initcol:ip=%{REMOTE_ADDR},id:1370

Then we can start storing information, lets say we will store how many times googlebot visit us total for up to 8 hours, when it will be reset.

SecRule REQUEST_HEADERS:User-agent "googlebot" "phase:1,nolog,id:1371,setvar:ip.counter=+1,pass"

We can then use this information to block googlebot requests if over 10 requests in last 8 hours.

SecRule ip:counter "@gt 10" "phase:1,log,msg:'googlebot has been blocked due to over 10 requests.',deny,id:1372"

You can also use AND in rules, in modsec this is done by using chains. Chained rules do not require ID.
Let say we will only block googlebot when it has over 10 requests and is visiting a specific file.

SecRule ip:counter "@gt 10" "phase:1,log,msg:'googlebot has been blocked due to over 10 requests.',deny,id:1372,chain"
SecRule REQUEST_URI "somefile.php" "t:none"

With this you should have grasped how modsecurity rules are written, and with the reference manual you can start doing magic ūüôā

Setting up IET (iSCSI Enterprise Target) on homeserver for vmware hypervisor.

Create folder for disk binary file.

mkdir -p /d2

Create binary disk file.

dd if=/dev/zero of=/d2/ds1.bin count=0 obs=1 seek=50G

Edit  /etc/iet/ietd.conf and insert text below.

Target iqn.2012-05.local.mynet:storage.sys0
Lun 0 Path=/d2/ds1.bin,Type=fileio,ScsiId=lun0,ScsiSN=lun0

MaxConnections 1
MaxSessions 0 
InitialR2T Yes
MaxRecvDataSegmentLength 81920
MaxXmitDataSegmentLength 81920
MaxBurstLength 2621440
FirstBurstLength 655360
DefaultTime2Wait 2
DefaultTime2Retain 0
MaxOutstandingR2T 1
DataPDUInOrder Yes
DataSequenceInOrder Yes
ErrorRecoveryLevel 0
HeaderDigest None,CRC32C
DataDigest None,CRC32C
NOPInterval 0
NOPTimeout 0 # Wait that many seconds for a
Wthreads 2
QueuedCommands 320

If you get errors like this one below in syslog, you might need to up the vallues above.

iscsi_trgt: Abort Task (01) issued on tid:1 lun:0 by sid:282574492336640 (Function Complete)

If this limit has been reached your iscsi target wont answer again until target service has been restarted.

Additional config.

Chap mutual

IncomingUser incusername incpasswd
OutgoingUser outusername outpasswd

Skip outgoing for one way chap.

Add more luns to your target,  add the following lines right bellow lun 0 in config above.

Lun 1 Path=/d2/ds2.bin,Type=fileio,ScsiId=lun1,ScsiSN=lun1
Lun 2 Path=/d2/ds3.bin,Type=fileio,ScsiId=lun2,ScsiSN=lun2

Example varnish config for Joomla and WordPress

This example has a webserver running on the same server on port 8080, this can easlily be changed by editing host ip and port vallues bellow.

The config does also not cache when logged in.
Cache will only store cache content for 5 minutes.

backend webserver {
.host = "127.0.0.1";
.port = "8080";
}
## Recieve
sub vcl_recv {
if (req.http.Accept-Encoding) {
if (req.http.Accept-Encoding ~ "gzip") {
# If the browser supports it, we'll use gzip.
set req.http.Accept-Encoding = "gzip";
}
else if (req.http.Accept-Encoding ~ "deflate") {
# Next, try deflate if it is supported.
set req.http.Accept-Encoding = "deflate";
}
else {
# Unknown algorithm. Remove it and send unencoded.
unset req.http.Accept-Encoding;
}
}
# Forward client's IP to backend
remove req.http.X-Forwarded-For;
set req.http.X-Forwarded-For = client.ip;
# Proxy (pass) any request that goes to the backend admin,
# the banner component links or any post requests
# You can add more pages or entire URL structure in the end of the "if"
if(req.http.cookie ~ "userID" || req.http.cookie ~ "wordpress_logged_in" || req.url ~ "^/administrator" || req.url ~ "^/component/banners" || req.request == "POST" || req.url ~ "wp-(login|admin)") {
return (pass);
}
# Check for the custom "x-logged-in" header to identify if the visitor is a guest,
# then unset any cookie (including session cookies) provided it's not a POST request
if(req.http.x-logged-in == "False" && req.request != "POST"){
unset req.http.cookie;
}
# Properly handle different encoding types
if (req.http.Accept-Encoding) {
if (req.url ~ "\.(jpg|jpeg|png|gif|gz|tgz|bz2|tbz|mp3|ogg|swf)$") {
# No point in compressing these
remove req.http.Accept-Encoding;
} elsif (req.http.Accept-Encoding ~ "gzip") {
set req.http.Accept-Encoding = "gzip";
} elsif (req.http.Accept-Encoding ~ "deflate") {
set req.http.Accept-Encoding = "deflate";
} else {
# unknown algorithm (aka crappy browser)
remove req.http.Accept-Encoding;
}
}
# Cache files with these extensions
if (req.url ~ "\.(js|css|jpg|jpeg|png|gif|gz|tgz|bz2|tbz|mp3|ogg|swf)$") {
return (lookup);
}
# Set how long Varnish will cache content depending on whether your backend is healthy or not
if (req.backend.healthy) {
set req.grace = 5m;
} else {
set req.grace = 1h;
}
return (lookup);
}
## Fetch
sub vcl_fetch {
# Check for the custom "x-logged-in" header to identify if the visitor is a guest,
# then unset any cookie (including session cookies) provided it's not a POST request
if(req.request != "POST" && beresp.http.x-logged-in == "False") {
unset beresp.http.Set-Cookie;
}
# Allow items to be stale if needed (this value should be the same as with "set req.grace"
# inside the sub vcl_recv {.} block (the 2nd part of the if/else statement)
set beresp.grace = 1h;
# Serve pages from the cache should we get a sudden error and re-check in one minute
if (beresp.status == 503 || beresp.status == 502 || beresp.status == 501 || beresp.status == 500) {
set beresp.grace = 60s;
return (restart);
}
# Unset the "etag" header (suggested)
unset beresp.http.etag;
if(beresp.http.Cache-Control == "no-cache" || beresp.http.Cache-Control == ""){
set beresp.http.Cache-Control = "max-age=300, public, must-revalidate";
}
# Don't allow static files to set cookies.
if (req.url ~ "(?i)\.(png|gif|jpeg|jpg|ico|swf|css|js|html|htm)(\?[a-z0-9]+)?$") {
# beresp == Back-end response from the web server.
unset beresp.http.set-cookie;
}
# Allow items to be stale if needed.
set beresp.grace = 6h;
unset beresp.http.Server;
set beresp.http.Server = "StarGazer";
## Remove the X-Forwarded-For header if it exists.
remove req.http.X-Forwarded-For;
remove req.http.X-Content-Encoded-By;
## insert the client IP address as X-Forwarded-For. This is the normal IP address of the user.
set    req.http.X-Forwarded-For = req.http.rlnclientipaddr;
## Deliver the content
set beresp.ttl = 300s;
set beresp.http.LiveForSec = beresp.ttl;
return(deliver);
}
## Deliver
sub vcl_deliver {
## We'll be hiding some headers added by Varnish. We want to make sure people are not seeing we're using Varnish.
## Since we're not caching (yet), why bother telling people we use it?
remove resp.http.X-Varnish;
remove resp.http.Via;
remove resp.http.Age;
remove resp.http.Vary;
## We'd like to hide the X-Powered-By headers. Nobody has to know we can run PHP and have version xyz of it.
remove resp.http.X-Powered-By;
}

Add custom build parameters for apache / php in cPanel.

In this example i will show how to install libvpx and compile php with vpx for webp support in php.

First we need to install the libraries from distros package repository.

yum install libvpx.x86_64 libvpx-devel.x86_64

Then we enter cPanels folder for custom options for easyapache.

cd /var/cpanel/easy/apache/rawopts

Then we need to make a file to add the options to, in this example we call it all_php5

nano all_php5

Then append the following text to file.

--with-vpx-dir

And now you can just recompile apache / php with easyapache and our cusom option will be compiled.

If you get any errors while running easyapache after adding a custom option like this its probably linked to missing library or not supported option for your version of php.
Check documentation on php.net.

Let nagios run binary as root under nrpe (non tty)

Enter edit mode for sudoers.

visudo

Add the following at the bottom.

Defaults:nagios !requiretty
nagios ALL = NOPASSWD: /usr/sbin/exim

And thats that.

Some explanation.

Normally   defaults requiretty  is set earlier in the file, which stops sudo from running while not under a tty (shell) we override this for nagios user by setting   defaults:nagios !requiretty as showed over.

Visudo is a command for opening /etc/sudoers in your distros default editor.

NOPASSWD does so command¬†does’nt need password to run sudo.

Add new harddrive to linux based vm while running

Scan for new disks, change hostX to active controller

echo "- - -" > /sys/class/scsi_host/hostX/scan

Check if system catched new disk.

fdisk -l

Add partition to new disk. change sdX with new disk identifier.

fdisk /dev/sdX
n (new partition)
p (primary partition)
1 (first partition)
[enter] (start at fist byte)
[enter] (end at last byte)
w (write changes)
Partition the new patition with a filesystem
mkfs.ext3 /dev/sdX#

Add automount of the new partition, edit and add to /etc/fstab.

/dev/sdX# /home2 ext3 defaults 1 0