Category: Uncategorized

SVN – Show Changed Files Between Revisions

March 15, 2013

To get a list of files changed between two revisions in subversion use this command:


svn diff -r [RNUM1]:[RNUM2] --summarize

svn diff -r [RNUM1]:[RNUM2] --summarize

Replace [RNUM1] and [RNUM2] with the revision numbers. [RNUM2] can be HEAD for the most recent version.

RackSpace Cloud Server With Multiple SSL Certificates

January 25, 2013

A recent configuration issue that we encountered involved trying to host multiple SSL enabled websites on a RackSpace Cloud Server with RackConnect. Each cloud server get’s only a single IP address but SSL requires each site to have a separate IP address. The work around then is to use a RackSpace Cloud Load Balancer to route additional IP addresses to the the cloud server on alternate ports. So for example if we have a cloud server at 10.10.10.1: a. https://www.acme.com points to 1.2.3.4:443 on the load balancer with the backend node configured to route to 10.10.10.1:8443 b. https://www.mace.com points to 1.2.3.5:443 on the load balancer with the backend node configured to route to 10.10.10.1:8444 b. https://www.case.com points to 1.2.3.6:443 on the load balancer with the backend node configured to route to 10.10.10.1:8445 Now this looks like it should work. On the cloud server we just have to configure each of

Plesk – Howto Clear Hung Database Copy

June 16, 2012

Recent versions of Plesk include a “Make a Copy” feature for databases. Unfortunately, on occasion the copy will fail but the copy task will not be removed. Then you’ll see a message like this every time you go to the affected database in Plesk. You can view a list of the current tasks with the following command from a root ssh login:

echo "select * from longtasks" | \
mysql --password=`cat /etc/psa/.psa.shadow` -u admin psa

1 2	echo "select * from longtasks" \| \ mysql --password=`cat /etc/psa/.psa.shadow` -u admin psa

You can clear the task by running the following command:

echo "delete from longtasks" | \
mysql --password=`cat /etc/psa/.psa.shadow` -u admin psa

1 2	echo "delete from longtasks" \| \ mysql --password=`cat /etc/psa/.psa.shadow` -u admin psa

Passive Mode FTP with iptables

March 8, 2012

There’s lots of advice on the net about how to setup a server with iptables to allow passive mode FTP. Below is the approach that we’ve found to be most effective. Start by configuring your FTP daemon to use a fixed range of ports. We use 41361 to 65534 which is the IANA registered ephemeral port range. The exact config depends on what FTP software you’re using: vsftpd Edit /etc/vsftpd/vsftpd.conf and add the following lines:

pasv_min_port=49152 
pasv_max_port=65534

1 2	pasv_min_port=49152 pasv_max_port=65534

proftpd Edit /etc/proftpd.conf and add to the Global section:

......
PassivePorts 49152 65534

......

PassivePorts 49152 65534

Now restart your FTP service so the changes take effect. Next you’ll need to configure the ip_conntrack_ftp iptables module to load. On Redhat/CentOS just edit /etc/sysconfig/iptables-config and add “ip_conntrack_ftp” to the IPTABLES_MODULES like this:

IPTABLES_MODULES="ip_conntrack_ftp"

1 2	IPTABLES_MODULES="ip_conntrack_ftp"

Next edit /etc/sysconfig/iptables and add a rule to allow TCP port 21. The new line is marked in red:

*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 21 -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
COMMIT

*filter

:INPUT ACCEPT [0:0]

:FORWARD ACCEPT [0:0]

:OUTPUT ACCEPT [0:0]

-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

-A INPUT -p icmp -j ACCEPT

-A INPUT -i lo -j ACCEPT

-A INPUT -m state --state NEW -m tcp -p tcp --dport 21 -j ACCEPT

-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT

-A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT

-A INPUT -j REJECT --reject-with icmp-host-prohibited

-A FORWARD -j REJECT --reject-with icmp-host-prohibited

COMMIT

Now restart the iptables service:

/sbin/service iptables restart

1 2	/sbin/service iptables restart

You can verify that

NFS Server On RackSpace Cloud

March 3, 2012

Today we’re going to setup an NFS server and client on a pair of RackSpace Cloud Servers. To get started create two cloud servers – one will be the NFS server and the other will be the NFS client. We’ll be using CentOS (RHEL) for our project but you can use the distribution of your choice. We’re going to do the NFS share over the Private Net interface which is a 10.x.x.x unroutable network. This way NFS is not exposed to the public network and the security issues are simplified. Our server will be named “file01” and our client will be “client01”. We will share the /data directory tree on the server and mount it to /data on the client. Server Install necessary packages. You’ll need nfs-utils and portmap. Additional dependent packages will be installed automatcially: