When I started hosting node.js apps, I just put them on different ports. So I would share links like “Check out Pathfinder at sam-the-man.com:3000“… which frankly doesn’t really represent the modern web very well, especially as a web-developer. What I really wanted was to put these apps onto different subdomains, but I didn’t want Apache to serve them, since node.js is perfectly capable of serving web applications.
I’m trying out HAProxy, which seems to do the job well so far.
I have HAProxy listening at port 80, and redirecting traffic to the node.js app mentioned above at the subdomain pathfinder.sam-the-man.com, and all other traffic currently gets sent to Apache which is listening on a different port. And Apache is still handling subdomains as well.
Here are the relevant parts of the HAProxy config file:
frontend http-farm bind *:80 mode http option httplog acl apache hdr(host) -m beg www. acl pathfinder hdr(host) -m beg pathfinder. use_backend apache_be if apache use_backend pf_be if pathfinder default_backend apache_be backend apache_be mode http server apache 127.0.0.1:9000 backend pf_be mode http server pathfinder 127.0.0.1:3000
So in the configuration file you have to define a “frontend”, which is the part that listens on a port and accepts requests, as well as routes those requests to the “backends”.
acl apache hdr(host) -m beg www. acl pathfinder hdr(host) -m beg pathfinder.
As you can see, we define a few rules in the frontend, with the acl keyword. The apache rule looks for anything beginning with “www.” and the pathfinder rules looks for anything beginning with “pathfinder.”
use_backend apache_be if apache use_backend pf_be if pathfinder default_backend apache_be
We then tell it to use the defined backend “apache_be” if the acl rule “apache” is true, or the “pf_be” backend if the “pathfinder” rule applies.
If neither of them apply, we use the “default_backend” as a catch all.
There are of course a lot more options that HAProxy (documentation) provides, this is just how I decided to initially set it up.