Basic Usage¶
Once it is set up and running, Tangelo’s basic usage is relatively straightforward. This chapter explains how Tangelo serves web content, a best practices guide for organizing your content, and how to use HTTP authentication to protect your content.
Serving Web Content¶
Tangelo’s most basic purpose is to serve web content. Once Tangelo is running, it will serve content from two types of locations:
Web root directory. Visiting most URLs (whose first path component is not
plugin
; see below) will cause Tangelo to serve content out of the web root
directory, which is set in the Tangelo configuration file, or by the -r
(or
--root
) flag when Tangelo is launched (see Setup and Administration). For example, if
the web root directory is set to /srv/tangelo/root
, visiting
http://localhost:8080/ would serve content from that directory, and visiting
http://localhost:8080/foobar would serve content from
/srv/tangelo/root/foobar
, etc.
Plugin content directories. The URLs rooted at http://localhost:8080/plugin refer to web
content served by any active Tangelo plugins. Each active plugin can have
static content associated with it, and such content is served from a directory
particular to each plugin. For information about how Tangelo plugins work, see
Tangelo Plugins. In partciular, this means that if there is a subdirectory of
the web root directory named plugin
, Tangelo will not be able to serve any
content from this directory.
The foregoing examples demonstrate how Tangelo associates URLs to directories and files in the filesystem. URLs referencing particular files will cause Tangelo to serve that file immediately. URLs referencing a directory behave according to the following rules:
- If the directory contains a file named
index.html
, that file will be served. - If Tangelo was launched with the
--list-dir
option, Tangelo will generate and serve a directory listing for the directory. This listing will include hyperlinks to the files contained therein. - Tangelo will serve a
403 Forbidden
error indicating that directory listing is disabled.
Furthermore, any URL referring to a Python script, but lacking the final .py
,
names a web service; such URLs do not serve static content, but rather run the
referred Python script and serve the results (see Tangelo Web Services).
The following table summarizes Tangelo’s URL types:
URL type | Example | Behavior |
---|---|---|
Web root | http://localhost:8080/holodeck3/status.html | serve /srv/tangelo/root/holodeck3/status.html |
Indexed directory | http://localhost:8080/tenforward | serve /srv/tangelo/root/tenforward/index.html |
Unindexed directory | http://localhost:8080/warpdrive | serve 403 Forbidden error, or directory listing for /srv/tangelo/root/warpdrive |
Web service | http://localhost:8080/lcars/lookup | serve result of executing run() function of /srv/tangelo/lcars/lookup.py |
Plugin | http://localhost:8080/plugin/foobar/... | serve content from foobar plugin |
HTTP Authentication¶
Tangelo supports HTTP Digest Authentication to password protect web directories. The process to protect a directory is as follows:
Go to the directory you wish to protect:
cd /srv/engineering/DilithiumChamberStats
The idea is, this directory (which is accessible on the web as http://localhost:8080/DilithiumChamberStats) contains sensitive information, and should be restricted to just certain people who have a password.
Create a file there called
.htaccess
and make it look like the following example, customizing it to fit your needs:AuthType digest AuthRealm USS Enterprise NCC-1701-D AuthPasswordFile /home/laforge/secret/dilithiumpw.txt
This file requestes digest authnetication on the directory, sets the authentication realm to be the string “USS Enterprise NCC-1701-D”, and specifies that the acceptable usernames and passwords will be found in the file
/home/laforge/secret/dilithiumpw.txt
.Currently, the only supported authentication type is digest. The realm will be displayed to the user when prompted for a username and password.
Create the password file, using the
tangelo-passwd
program (see tangelo-passwd):$ tangelo-passwd -c ~laforge/secret/dilithiumpw.txt "USS Enterprise NCC-1701-D" picard Enter password for picard@USS Enterprise NCC-1701-D: <type password here> Re-enter password: <retype password here>
This will create a new password file. If you inspect the file, you will see a user
picard
associated with an md5 hash of the password that was entered. You can add more users by repeating the command without the-c
flag, and changing the username.At this point, the directory is password protected - when you visit the page, you will be prompted for a username and password, and access to the page will be restricted until you provide valid ones.