Archive for the ‘Administration’ Category

Logs monitoring

четвъртък, април 9th, 2009

I have been asked from one my friends who hosts many websites on single machine to help him to find which vhost is doing some slow requests.

the load of the machine from 0.5 has become 1.5. and there are some apache processess eating the CPU.

It is obvious that some php file is slowing down all the machine but who?

I found this wonderfull tool in Internet

http://code.google.com/p/wtop/wiki/Installing

http://code.google.com/p/wtop/wiki/LogrepCookbook

With this script I can monitor all the pages and not sitting in the dark while some evil pages are drying the CPU power.

logrep -m tail -f 'msec>1000' -o 'ts,ip,msec,class,url' *.log

One server, two bind/named process, one domain (with two nameservers)

вторник, февруари 24th, 2009

Yes you need two bind instances

When you register a domain name you provide two nameservers.

Those nameservers the registrarar will know their ip addresses.

in my example the domain is cenite.com and the nameservers are ns1.cenite.com and ns2.cenite.com

Both nameservers are running on signle debian machine. I have started two bind processes on the machine. one is binded to the ns1.cenite.com external interface and ns2.cenite.com is to the other (backup) internet interface.

Here is a tool to check your domain name

Here is example zone file

cenite.com.db

cenite.com.ns2.db

here are the configuration files.

named2.conf

named.conf

The good think is when the first internet connection is down, the second will still serve your clients.

Bonus links

Go and switch to tinydns – people say it is much easier to configure  http://cr.yp.to/djbdns/run-server-bind.html

dns zone generator

How to create a self-signed SSL Certificate …

събота, януари 3rd, 2009

Low cost certificates

Certificates in this category should cost under US$50 annually and include availability from Trusted CAs ipsCA and FreeSSL.com. As these certificates do not carry a known brand, fraud control or human support, they are suitable for non- or light commerce environments, though they do provide bonus 128-bit encryption. According to FreeSSL.com, a light commerce environment is one with no more than 50 transactions weekly, and an average transaction value of US$50.

How to create a self-signed SSL Certificate …

…  which can be used for testing purposes or internal usage


Overview

The following is an extremely simplified view of how SSL is implemented and what part the certificate plays in the entire process.

Normal web traffic is sent unencrypted over the Internet. That is, anyone with access to the right tools can snoop all of that traffic. Obviously, this can lead to problems, especially where security and privacy is necessary, such as in credit card data and bank transactions. The Secure Socket Layer is used to encrypt the data stream between the web server and the web client (the browser).

SSL makes use of what is known as asymmetric cryptography, commonly referred to as public key cryptography (PKI). With public key cryptography, two keys are created, one public, one private. Anything encrypted with either key can only be decrypted with its corresponding key. Thus if a message or data stream were encrypted with the server’s private key, it can be decrypted only using its corresponding public key, ensuring that the data only could have come from the server.

If SSL utilizes public key cryptography to encrypt the data stream traveling over the Internet, why is a certificate necessary? The technical answer to that question is that a certificate is not really necessarythe data is secure and cannot easily be decrypted by a third party. However, certificates do serve a crucial role in the communication process. The certificate, signed by a trusted Certificate Authority (CA), ensures that the certificate holder is really who he claims to be. Without a trusted signed certificate, your data may be encrypted, however, the party you are communicating with may not be whom you think. Without certificates, impersonation attacks would be much more common.

Step 1: Generate a Private Key

The openssl toolkit is used to generate an RSA Private Key and CSR (Certificate Signing Request). It can also be used to generate self-signed certificates which can be used for testing purposes or internal usage.

The first step is to create your RSA Private Key. This key is a 1024 bit RSA key which is encrypted using Triple-DES and stored in a PEM format so that it is readable as ASCII text.

openssl genrsa -des3 -out server.key 1024

Generating RSA private key, 1024 bit long modulus
…………………………………………………++++++
……..++++++
e is 65537 (0×10001)
Enter PEM pass phrase:
Verifying password – Enter PEM pass phrase:

Step 2: Generate a CSR (Certificate Signing Request)

Once the private key is generated a Certificate Signing Request can be generated. The CSR is then used in one of two ways. Ideally, the CSR will be sent to a Certificate Authority, such as Thawte or Verisign who will verify the identity of the requestor and issue a signed certificate. The second option is to self-sign the CSR, which will be demonstrated in the next section.

During the generation of the CSR, you will be prompted for several pieces of information. These are the X.509 attributes of the certificate. One of the prompts will be for “Common Name (e.g., YOUR name)”. It is important that this field be filled in with the fully qualified domain name of the server to be protected by SSL. If the website to be protected will be https://public.akadia.com, then enter public.akadia.com at this prompt. The command to generate the CSR is as follows:

openssl req -new -key server.key -out server.csr

Country Name (2 letter code) [GB]:CH
State or Province Name (full name) [Berkshire]:Bern
Locality Name (eg, city) [Newbury]:Oberdiessbach
Organization Name (eg, company) [My Company Ltd]:Akadia AG
Organizational Unit Name (eg, section) []:Information Technology
Common Name (eg, your name or your server’s hostname) []:public.akadia.com
Email Address []:martin dot zahn at akadia dot ch
Please enter the following ‘extra’ attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:

Step 3: Remove Passphrase from Key

One unfortunate side-effect of the pass-phrased private key is that Apache will ask for the pass-phrase each time the web server is started. Obviously this is not necessarily convenient as someone will not always be around to type in the pass-phrase, such as after a reboot or crash. mod_ssl includes the ability to use an external program in place of the built-in pass-phrase dialog, however, this is not necessarily the most secure option either. It is possible to remove the Triple-DES encryption from the key, thereby no longer needing to type in a pass-phrase. If the private key is no longer encrypted, it is critical that this file only be readable by the root user! If your system is ever compromised and a third party obtains your unencrypted private key, the corresponding certificate will need to be revoked. With that being said, use the following command to remove the pass-phrase from the key:

cp server.key server.key.org
openssl rsa -in server.key.org -out server.key

The newly created server.key file has no more passphrase in it.

-rw-r–r– 1 root root 745 Jun 29 12:19 server.csr
-rw-r–r– 1 root root 891 Jun 29 13:22 server.key
-rw-r–r– 1 root root 963 Jun 29 13:22 server.key.org

Step 4: Generating a Self-Signed Certificate

At this point you will need to generate a self-signed certificate because you either don’t plan on having your certificate signed by a CA, or you wish to test your new SSL implementation while the CA is signing your certificate. This temporary certificate will generate an error in the client browser to the effect that the signing certificate authority is unknown and not trusted.

To generate a temporary certificate which is good for 365 days, issue the following command:

openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt
Signature ok
subject=/C=CH/ST=Bern/L=Oberdiessbach/O=Akadia AG/OU=Information
Technology/CN=public.akadia.com/Email=martin dot zahn at akadia dot ch
Getting Private key

Step 5: Installing the Private Key and Certificate

When Apache with mod_ssl is installed, it creates several directories in the Apache config directory. The location of this directory will differ depending on how Apache was compiled.

cp server.crt /usr/local/apache/conf/ssl.crt
cp server.key /usr/local/apache/conf/ssl.key

Step 6: Configuring SSL Enabled Virtual Hosts

SSLEngine on
SSLCertificateFile /usr/local/apache/conf/ssl.crt/server.crt
SSLCertificateKeyFile /usr/local/apache/conf/ssl.key/server.key
SetEnvIf User-Agent “.*MSIE.*” nokeepalive ssl-unclean-shutdown
CustomLog logs/ssl_request_log \
“%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \”%r\” %b”

Step 7: Restart Apache and Test

/etc/init.d/httpd stop
/etc/init.d/httpd stop

https://public.akadia.com

NTP configuration

събота, декември 27th, 2008
To initially setup the time if there is a big difference you can use the following command
 /usr/sbin/ntpdate -s -b -p 8 -u yourISP.NTP.Server.IP
    Debian:
    Setting timezone:
    sudo dpkg-reconfigure tzdata
    
    /etc/ntp.conf
    server 0.bg.pool.ntp.org
    server 1.europe.pool.ntp.org
    server 2.europe.pool.ntp.org
    Great references http://www.akadia.com/services/ntp_synchronize.html

    hwclock –systohc

    Trac administration

    вторник, октомври 14th, 2008

    Trac
    ==Start the administration==
    trac-admin /home/domains/spider/trac-dagensps

    ==Run the server with==
    tracd –auth=*,/home/domains/spider/.passwords,spider.bg –port 8000 /home/domains/spider/trac_envs/dagensps /home/domains/spider/trac_envs/trucks

    ==Add users==
    htdigest /home/domains/spider/.passwords spider.bg a.inkov@spider.bg

    ==Apache Integration==

    http://trac.edgewall.org/wiki/TracCgi#AddingAuthentication

    Here is what I use to start the trac in spider:
    router:/home/domains/spider# cat trac.start.sh
    #!/bin/bash
    tracd –port 8000 \
    –auth=dagensps,/home/domains/spider/.passwords,spider.bg /home/domains/spider/trac_envs/dagensps \
    –auth=trucks,/home/domains/spider/.passwords,spider.bg /home/domains/spider/trac_envs/trucks \
    –auth=bbi,/home/domains/spider/.bbi_passwords,spider.bg /home/domains/spider/trac_envs/bbi/

    Bash tips and tricks

    вторник, август 26th, 2008

    Nice quick bash book

    http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO-7.html (loops)

    How to check if files containt “this” and “that”

    grep -i 'for nut in self._foundNuts:' `grep -ril "loop(1):" *`

    Display timestamp

    date -d @1231351762

    Nginx with Rails

    вторник, август 19th, 2008

    downloaded from here
    documentation here
    If you want to try different solution check it haproxy (още…)

    Debian/Ubunto notes

    вторник, юли 15th, 2008

    How to save and installed packges

    http://www.cyberciti.biz/tips/linux-get-list-installed-software-reinstallation-restore.html

    $ dpkg --get-selections > /backup/installed-software.log

    # dpkg --set-selections < /backup/installed-software.log

    Now your list is imported use dselect or other tools to install the package.
    # dselect

    Select ‘i‘ for install the software.

    Upgrade Debian

    http://www.cyberciti.biz/tips/upgrading-debian-sarga-3-to-etch-4.html

    Commands

    cat /etc/debian_version

    Fix the W: There are no public key available for the following key IDs:

    4D270D06F42584E6

    apt-key update

    gpg –keyserver wwwkeys.eu.pgp.net –recv-keys XXXXXXXXXXXXXXXX
    apt-key add /root/.gnupg/pubring.gpg
    apt-get update

    debian tracd initscript

    вторник, юли 15th, 2008

    Trac startup script.

    (още…)

    Gentoo Cheatsheet

    сряда, юни 11th, 2008

    Java install

    ls /usr/portage/dev-java/sun-jdk/
    emerge -av =dev-java/sun-jdk-1.5.0.13
    java-config -L
    java-config -S 1
    /usr/sbin/env-update && source /etc/profile

    Emerge and Equery

    Taken from here

    emerge brings in new packages. equery looks at the package database.

    update repository:
    emerge –sync
    install package with query
    emrge -av sun-jdk
    start with this software
    emerge links wget htop
    emerge …
    manipulate package database
    emerge -NDtu world
    –update packages and packages that depend on updated packages (–deep) in the world list. Give output in –tree format. Consider packages changed if their USE flags have changed (–newuse, -N) Add –pretend (-p) to just see what it will do first.
    emerge –skipfirst …
    skip first pkg on a rebuild; very useful if something doesn’t work
    equery …
    query package database
    equary belongs
    who owns these files?
    equery list
    list packages on system

    Maintenance

    Taken from here

    Do this whenever you want a steaming pile of fresh packages.

    # emerge --sync
    # emerge --update system
    # etc-update
    if necessary
    # emerge --update world

    I have seen Meddle to do it this way

    emerge –newuse –deep –update world
    emerge –ask –verbose coreutils
    emerge –resume

    Fix the mktemp / coreutils block in Gentoo

    Looks like mktemp is now provided by coreutils. No wonder. This block has been bugging me (read: I’ve been ignoring it) for months.

    To fix just unmerge mktemp and update coreutils.

    Update: Same for the setarch / util-linux block should you come across it. Unmerge setarch.