Smeagol is a simple Wiki engine inspired by Gollum. Gollum is a Wiki engine written in Ruby, which uses a number of simple text formats including Markdown, and which uses Git to provide versioning and backup. I needed a new Wiki for a project and thought Gollum would be ideal - but unfortunately it doesn't provide user authentication, which I needed, and it was simpler for me to reimplement the bits I did need in Clojure than to modify Gollum.
So at this stage Smeagol is a Wiki engine written in Clojure which uses Markdown as its text format, which does have user authentication, and which uses Git as its versioning and backup system.
Smeagol is now a fully working small Wiki engine, and meets my own immediate needs.
Smeagol uses the Markdown format as provided by markdown-clj, with the addition that anything enclosed in double square brackets, [[like this]], will be treated as a link into the wiki itself.
A system of pluggable, extensible formatters is supported. In normal markdown, code blocks may be delimited by three backticks at start and end, and often the syntax of the code can be indicated by a token immediately following the opening three backticks. This has been extended to allow custom formatters to be provided for such code blocks. Two example formatters are provided:
Inspired by visdown and vega-lite, the Vega formatter allows you to embed vega data visualisations into Smeagol pages. The graph description should start with a line comprising three back-ticks and then the word 'vega', and end with a line comprising just three backticks.
Here's an example cribbed in its entirety from here:
data:
url: "data/london.csv"
transform:
-
filter: datum.year == 2016
mark: rect
encoding:
x:
type: nominal
field: source
y:
type: nominal
field: dest
color:
type: quantitative
field: flights
aggregate: sum
Data files can be uploaded in the same way as images, by using the upload a file link.
Note that this visualisation will not be rendered in the GitHub wiki, as it doesn't have Smeagol's data visualisation magic. This is what it should look like:
Graphs can now be embedded in a page using the Mermaid graph description language. The graph description should start with a line comprising three back-ticks and then the word mermaid, and end with a line comprising just three backticks.
Here's an example culled from the Mermaid documentation.
gantt
dateFormat YYYY-MM-DD
title Adding GANTT diagram functionality to mermaid
section A section
Completed task :done, des1, 2014-01-06,2014-01-08
Active task :active, des2, 2014-01-09, 3d
Future task : des3, after des2, 5d
Future task2 : des4, after des3, 5d
section Critical tasks
Completed task in the critical line :crit, done, 2014-01-06,24h
Implement parser and jison :crit, done, after des1, 2d
Create tests for parser :crit, active, 3d
Future task in critical line :crit, 5d
Create tests for renderer :2d
Add to mermaid :1d
To add your own formatter, compile it into a jar file which is on the classpath - it does not have to be part of the Smeagol project directly, and then edit the value of the key :formatters in the file config.edn; whose standard definition is:
:formatters {"vega" smeagol.formatting/process-vega
"vis" smeagol.formatting/process-vega
"mermaid" smeagol.formatting/process-mermaid}
The added key should be the word which will follow the opening three backticks of your code block, and the value of that key should be a symbol which evaluates to a function which can format the code block as required.
Security is now greatly improved. There is a file called passwd in the resources directory, which contains a clojure map which maps usernames to maps with plain-text passwords and emails thus:
{:admin {:password "admin" :email "admin@localhost" :admin true}
:adam {:password "secret" :email "adam@localhost"}}
that is to say, the username is a keyword and the corresponding password is a string. However, since version 0.5.0, users can now change their own passwords, and when the user changes their password their new password is encrypted using the scrypt one-way encryption scheme. The password file is now no longer either in the resources/public directory so cannot be downloaded through the browser, nor in the git archive to which the Wiki content is stored, so that even if that git archive is remotely clonable an attacker cannot get the password file that way.
You can (if you're logged in) upload files, including images, using the Upload a file link on the top menu bar. You can link to an uploaded image, or other images already available on the web, like this:
You can include pages into the current page you're working on. To do so, you can add a include link:
&[:indent-heading s/Num :indent-list s/Num](relative or absolute uri s/Str)
Parameters semantics:
- uri: The page to include. At the moment only pages from the current wiki are allowed. A page called "PageToBeIncluded" will result in a uri "PageToBeIncluded.md".
- indent-heading: You can indent headings of included page to adjust the included content to your surrounding structure. Indents 0-9 are supported.
- indent-list: In Same manner you can indent lists of included page to adjust the included content to your surrounding structure. Indents 0-9 are supported.
Security warning: At the moment there is no check against directory traversal attack. So include feature may expose files outside of your wiki content-dir.
If you like what you see here, I am available for work on open source Clojure projects.
Smeagol currently requests the WEFT logo in the page footer from my home site. This is mainly so I can get a feel for how many people are using the product. If you object to this, edit the file
resources/templates/base.html
and replace the line
<img height="16" width="16" alt="The Web Engineering Factory & Toolworks" src="http://www.weft.scot/images/weft.logo.64.png"> Developed by <a href="http://www.weft.scot/">WEFT</a>
with the line
<img height="16" width="16" alt="The Web Engineering Factory & Toolworks" src="img/weft.logo.64.png"> Developed by <a href="http://www.weft.scot/">WEFT</a>
Copyright © 2014-2015 Simon Brooke. Licensed under the GNU General Public License, version 2.0 or (at your option) any later version. If you wish to incorporate parts of Smeagol into another open source project which uses a less restrictive license, please contact me; I'm open to dual licensing it.
You will need Leiningen 2.0 or above installed.
You will need node and bower installed.
To start a web server for the application, run:
lein bower install
lein ring server
Alternatively, if you want to deploy to a servlet container (which I would strongly recommend), the simplest thing is to run:
lein bower install
lein ring uberwar
(a command which I'm sure Smeagol would entirely appreciate) and deploy the resulting war file.
You can now run Smeagol as a Docker image. To run my Docker image, use
docker run simonbrooke/smeagol
Smeagol will run, obviously, on the IP address of your Docker image, on port 8080. To find the IP address, start the image using the command above and then use
docker inspect --format '{{ .NetworkSettings.IPAddress }}' $(docker ps -q)
Suppose this prints '10.10.10.10', then the URL to browse to will be http://10.10.10.10:8080/smeagol/
This image is experimental, but it does seem to work fairly well. What it does not yet do, however, is push the git repository to a remote location, so when you tear the Docker image down your edits will be lost. My next objective for this image is for it to have a cammand line parameter being the git address of a repository from which it can initialise the Wiki content, and to which it will periodically push local changes to the Wiki content.
To build your own Docker image, run:
lein clean
lein bower install
lein ring uberwar
lein docker build
This will build a new Docker image locally; you can, obviously, push it to your own Docker repository if you wish.