Once your mac has SSH enabled, log into your Ubuntu machine and click Places –> Connect To Server. Choose SSH as your Service Type. Enter in the IP address of your mac or whatever name you may have assigned to it in your /etc/hosts file or whatever. Use the username and password you use to log into mac and there you go. You can browse files on your mac with your Ubuntu machine in Nautilus.

One of the smartest people I’ve ever digitally met, Ryan Paul, taught me this awesome tip for doing a project wide search in vim. I needed to look for all occurrences of the patter _Models_ in a PHP project I was working on and you can do it right inside of vim – the best text editor ever invented.

1. Open vim and make sure you are in the top level folder of your project by typing :pwd
2. Then type :vimgrep YourPattern **/*.php
3. To open your search results in their own buffer type :copen

The **/ recursively searches through all your directories for you pattern. :copen opens the search results in their own buffer. You can use the arrow keys to move up and down through the list and hit enter to have it open that result in the main buffer. You can also use :cnext and :cprev to move to the next and previous items in the list. Perhaps you might bind those to keyboard shortcuts so you can move through the search results quickly.

I have been using vim for a couple years and every week it seems I learn some new feature or trick you can do. Recently I learned how to convert a selection to either all uppercase or all lowercase letters.

Convert a visual selection to all uppercase letters.

gU

Convert to lowercase letters

gu

Download and install scanbuttond which is a daemon that allows you to invoke actions such as shell scripts whenever one of the scanner front panel buttons is pressed. I do not use my scanners buttons, and this tip will work even if your scanner doesn’t have any buttons. The daemon periodically polls the scanner helping to prevent it from suspending and becoming unresponsive. So start up a terminal and…

sudo apt-get install scanbuttond
scanbuttond -r 1000000

The 1000000 is the number of microseconds between polls to the scanner. So the scanbuttond deamon will poll your scanner once per second. If you are finished with your scanning, and want to stop the scanbuttond daemon from polling your scanner, simply stop the daemon.

killall scanbuttond

We are running Apache 2.0 and proxying to a Mongrel cluster for our latest e-commerce website QuietHeadphones.com which is scheduled to be launched at the end of June. Being an e-commerce site we needed to put the checkout functionality behind SSL. Since Apache is handling both the HTTPS/SSLfunctionality as well as the standard HTTP requests and proxying everything to the Mongrel cluster, the Mongrel cluster doesn’t know which requests are HTTPS and which are HTTP. To tell Rails which requests are HTTPS requests you can set up an environment variable in the Apache virtual host configuration in the httpd.conf file. The environement variable is:

RequestHeader set X_FORWARDED_PROTO ‘https’

In Rails, request.rb checks for that variable and pleasantly handles everything else for you.

Now if you are using ISPConfig to manage the virtual hosts on your web server, you will notice that there is no way to separate SSL vs non-SSL Apache directives using the web interface. Since most of our sites are Ruby on Rails sites and since the RequestHeader variable doesn’t hurt anything if you aren’t using rails, I revised the source code of ISPConfig to always include the RequestHeader set X_FORWARDED_PROTO line in all of the SSL virtual host configurations. That way, anytime you set up a site in ISPConfig and select the SSL option, ISPConfig faithfully inserts the RequestHeader line so that Mongrel knows what sort of requests it is getting.

To make this revision to ISPConfig, open up config.lib.php then edit the SSL-Web section at approximately line 1521 by adding RequestHeader set X_FORWARDED_PROTO ‘https’

file: /root/ispconfig/scripts/lib/config.lib.php

RequestHeader set X_FORWARDED_PROTO ‘https’

Once that is in place, all HTTPS requests will have that request header variable set and regular HTTP requests will not. Then you can use the standard web interface to configure the rest of the Apache directives for your Ruby on Rails application and the Mongrel cluster. Here’s an example of what the Apache Directives text box may look like in ISPConfig.

<Proxy *>
Order allow,deny
Allow from all
</Proxy>

ProxyRequests Off
ProxyPassReverse / http://www.mydomain.com:9001/
ProxyPassReverse / http://www.mydomain.com:9002/
ProxyPassReverse / http://www.mydomain.com:9003/
ProxyPreserveHost On
RewriteEngine On
RewriteMap servers rnd:/var/www/webX/rails/map.txt
RewriteRule ^/(images|stylesheets|javascripts)/?(.*) $0 [L]
RewriteRule ^/(.*)$ http://www.mydomain.com:${servers:ports}/$1 [P,L]
Alias /images /var/www/webX/web/images
Alias /stylesheets /var/www/webX/web/stylesheets
Alias /javascripts /var/www/webX/web/javascripts
SSLCertificateChainFile /var/www/webX/ssl/gd_intermediate_bundle.crt

There are a couple things to note in this example. At the time of this writing, we are using Apache 2.0 and, therefore, don’t have access to the mod_proxy_balancer that many people are enjoying with Apache 2.2. Nevertheless, we wanted to run a Mongrel cluster so we are using a randomized proxy balancer by taking advantage of the RewriteMap feature of Apache 2.0. We created a text file that contains the port numbers that each of our Mongrel instances are using separated by pipes as follows:

file: map.txt

ports 9001|9002|9003

Then on each request, Apache randomly selects on of the three ports from the map.txt file and rewrites the request for one of our mongrel instances.

RewriteRule ^/(.*)$ http://www.mydomain.com:${servers:ports}/$1 [P,L]

Lastly, if you buy an SSL certificate from godaddy.com, you will need to add the SSLCertificateChainFile directive to your Apache configuration. Otherwise, most – perhaps all – browsers will complain about the ssl certificate not being trusted. Once you know about that, it’s an easy adjustment to make. Simply give Apache the path to the gd_intermediate_bundle.crt that you will get when you buy your ssl certificate at GoDaddy.com

Page six of the Perfect Setup tutorial says that you should add the following lines to your proftpd.conf file.

vi /etc/proftpd/proftpd.conf
…
DefaultRoot ~
IdentLookups off
ServerIdent on “FTP Server ready.”
…

I found that if I include those lines inside of <Global>…</Global> tags the delay goes away and I am instantly logged into the server. So, instead of the above format, add those lines inside the Global tags like this.

vi /etc/proftpd/proftpd.conf
…
<Global>
DefaultRoot ~
IdentLookups off
ServerIdent on “FTP Server ready.”
</Global>
…

File: /etc/ssh/ssh_config
…
  HashKnownHosts yes
# GSSAPIAuthentication yes
  GSSAPIDelegateCredentials no
…

GSSAPIAuthentication specifies whether user authentication based on GSSAPI is allowed. Connections with GSSAPIAuthentication option enabled on non-kerberos SSH servers are very slow. If you run ssh in verbose mode you may get a “Miscellaneous failure” error message.

ssh -v -l example.com
…
debug1: Miscellaneous failure
No credentials cache found
…

After disabling GSSAPIAuthentication, you probably won’t have to wait as long to get your login in prompt.

May 8 05:46:07 hostname postfix/smtp: 23E507C950: to=, relay=mx1.hotmail.com[65.54.244.136]:25, delay=0.6, delays=0.26/0.01/0.15/0.18, dsn=2.0.0, status=sent (250 <20070508054607.23E507C950@hostname.com> Queued mail for delivery)

Mail was successfully leaving my server and Hotmail was reporting back that the mail was successfully sent yet the mail was not ever getting delivered to my hotmail inbox. The solution is to make sure you have a valid SPF record for your domain. Microsoft has an online wizard to help you create the SPF record.

When you are creating the record, make sure not to include a “ptr” lookup. I got this email from Microsoft when trying to figure all this out.

We reviewed your SPF record and note that it includes the “ptr” or reverse DNS lookup mechanism. The specification for SPF records (RFC 4408) discourages use of “ptr” for performance and reliability reasons. This is especially important for Windows Live Mail, Hotmail and other large ISPs as a result of the very high volume of mail we receive each day. We highly recommend you remove the “ptr” mechanism from your SPF record and, if necessary, replace it with other SPF mechanisms that do not require a reverse DNS lookup, such as “a”, “mx”, “ip4” and “include.” This will help ensure that Sender ID validation is performed as accurately as possible, maximizing your email deliverability while protecting your domain from spoofing.

Finally, you need to create a TXT DNS entry. Allow about 24 hours or so, and Hotmail and MSN will start accepting your mail. Note, however, they may be sending it to your Junk Mail folder.