YAWS Installation in Ubuntu

Today I tried installing YAWS into Ubuntu 10.10. Installation is so easy that apt packages and repositories are ready to work.

First, use the following command to put on the software:

apt-get install yaws yaws-yapp

Then I got configuration files set in /etc/yaws/conf.d/ accompanied with a basis configuration file /etc/yaws/yaws.conf. What located in /etc/yaws/conf.d/ are soft links to correspondent files in /etc/yaws/conf.available/. Note that if you install YAWS in Ubuntu but cannot see any files when trying listing files in the route /etc/yaws/conf.d/, it’s specific privilege restrict, you can use emacs in sudo mode to list folders. There are files including localhost.conf, localhost-ssl.conf, yaws-yapp.conf, and etc. I did not need a web site working on HTTP, and then I deleted /etc/yaws/conf.d/localhost.conf. I need a web site with SSL so I edited /etc/yaws/conf.d/localhost-ssl.conf as below:

<server localhost>
    port = 443
    listen = 0.0.0.0
    docroot = /usr/share/yaws
    # dir_listings = true
    <ssl>
        keyfile = /etc/yaws/yaws-key.pem
        certfile = /etc/yaws/yaws-cert.pem
    </ssl>
</server>

By default it uses its SSL cert- and key- files, and the port 8443. I would like to run it on the well-known port for HTTPS protocol, and then I changed the port number. Note that if the port 443 is bound by another web server and then YAWS, YAWS service won’t be start properly. I have not yet know if it supports virtual directories by tracing symbolic links. Then, when configuration was done, I restart it by using the following command:

service yaws restart

YAWS lets you use “ehtml" to embed Erlang code with YAWS BIFs. Erlang modules can be used either by installing compiled codes in /usr/lib/yaws/ebin/ or by putting Erlang header files *.hrl in /usr/lib/yaws/include/. To install compiled Erlang modules into YAWS, follow these steps:

1. Write Erlang programs in *.erl.
2. Compile modules by using erlc, and check *.beam files are generated.
3. Copy *.beam files to /usr/lib/yaws/ebin/.
4. Call those custom functions in ehtml blocks in *.yaws pages.