Month: June 2011

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node.js on ubuntu (on linode)

I got my simple movies node.js app running through Apache using mod_proxy

$ a2enmod proxy_http
$ a2enmod proxy

Configured under sites-available like so:

$ cat /etc/apache2/sites-available/movies 
<VirtualHost *:80>
    ServerName actualfqdnofhost.bluebones.net
    ServerAlias movies.bluebones.net
    ProxyPass / http://127.0.0.1:3000/
    <Proxy *>
	Allow from all
    </Proxy>
</VirtualHost>

(This assumes that your app listens on port 3000 when running.)

Then to ensure it gets restarted when the machine does I created the following file as /etc/init/movies.conf

$ cat /etc/init/movies.conf 
description "movies.bluebones.net on node.js"
author "bakert"

start on startup
stop on shutdown

script
  export MOVIES_ROOT=/srv/movies
  export EXPRESS_ROOT=$MOVIES_ROOT/src/express
  cd $EXPRESS_ROOT && exec sudo -u www-data NODE_PATH=$NODE_PATH:/opt/local/node/lib/node_modules/ EXPRESS_ENV=production /opt/local/node/bin/node $EXPRESS_ROOT/app.js 2>&1 >>$MOVIES_ROOT/logs/node.log
end script

Which also lets me stop and start my app with:

$ start movies
$ stop movies
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Set up an SPF Record to (theoretically) reduce the risk of your web app’s email being marked as spam

I’m setting up email sending from my domain instead of faking gmail.com because of mail delivery issues. To make this work without just going automatically to everyone’s spam folder I have set up an SPF record. I found the documentation on the web a bit dense trying to work this out so here’s a short look at what I did.

“Show Original” in gmail used to say:

Received-SPF: neutral (google.com: 74.54.101.112 is neither permitted nor denied by domain of bakert+fantasyfootball@gmail.com) client-ip=74.54.101.112;
Authentication-Results: mx.google.com; spf=neutral (google.com: 74.54.101.112 is neither permitted nor denied by domain of bakert+fantasyfootball@gmail.com) smtp.mail=bakert+fantasyfootball@gmail.com

Now it says:

Received-SPF: pass (google.com: domain of admin+2@ff.bluebones.net designates 178.79.178.155 as permitted sender) client-ip=178.79.178.155;
Authentication-Results: mx.google.com; spf=pass (google.com: domain of admin+2@ff.bluebones.net designates 178.79.178.155 as permitted sender) smtp.mail=admin+2@ff.bluebones.net

This means Gmail is less likely to mark email sent by my web app as spam, thanks to the SPF record I have set up.

An SPF record is implemented as a DNS TXT (as opposed to A, CNAME, etc.) record with no “name” and a value something like this:

v=spf1 a mx include:_spf.google.com ~all

Let’s break that down …

v=spf1 – this indicates that the record is an SPF v1 record.

A – this indicates that any IP address in an A record for this network is allowed to send email for this domain.

MX – this indicates that any IP address in an MX record for this network is allowed to send email for this domain.

include:_spf.google.com – this indicates that _spf.google.com is allowed to send email for this domain.

~all – this indicates that _spf.google.com is allowed to send email for this domain.

All parts of the record except v=spf1 are optional and can take a prefix of -, + or ~. If there is no prefix + is assumed. + means allowed, – means not allowed and ~ means might be allowed. all is the catch-all for anything not explicitly called out by the rule.

You might be interested in a more detailed guide to SPF record syntax.

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Setup NS Records for Subdomain

If you want to serve DNS for a subdomain while keeping most of the DNS records to do with its domain with another DNS provider you need NS records.

On the nameserver for example.com:

somesubdomain			NS	ns1.otherprovider.net
somesubdomain			NS	ns2.otherprovider.net
somesubdomain			NS	ns3.otherprovider.net
somesubdomain			NS	ns4.otherprovider.net

On the otherprovider.net nameserver for somesubdomain.example.com you just need a “normal” A record (+CNAME/MX/whatever):

somesubdomain			A	178.79.178.155

I have this setup working with everydns.net providing most of my DNS but linode providing DNS for the sites I have moved off my old providers and on to linode.

The previously wonderful everydns that served me well for many years (for nothing!) has been bought up and is going paid in less than 90 days so I’m taking this opportunity to move things around.