Note
This is the development-oriented readme. If you want to write notes for
end users, please put them in dist/README
.
Hue is both a web UI for Hadoop and a framework to create interactive web applications. It features a FileBrowser for accessing HDFS, JobSub and JobBrowser applications for submitting and viewing MapReduce jobs, a Beeswax application for interacting with Hive. On top of that, the web frontend is mostly built from declarative widgets that require no JavaScript and are easy to learn.
The "core" stuff is in desktop/core/
, whereas installable apps live in
apps/
. Please place third-party dependencies in the app's ext-py/
directory.
The typical directory structure for inside an application includes:
- src/
- for Python code
- conf/
- for configuration (
.ini
) files to be installed- static/
- for static HTML and js resources
- templates/
- for data to be put through a template engine
- docs/
- for helpful notes
The python code is structured simply as
module/package.py
,
where module may be "filebrowser" or "jobsub". Because it is unlikely that
there are going to be huge conflicts, we're going without a deep nested
hierarchy.
core/src/desktop/urls.py
contains the current layout for top-level URLs.
For the URLs within your application, you should make your own urls.py
which will be automatically rooted at /yourappname/
in the global
namespace. See apps/hello/src/hello/urls.py
for an example.
On your host system, you need to have the python "virtualenv" package installed.
Also, you'll need these library development packages installed on your system:
- Debian:
- gcc
- libmysqlclient-dev
- libsasl2-dev
- libsqlite3-dev
- libxml2-dev
- libxslt-dev
- python-dev
- python-setuptools
- CentOS:
- cyrus-sasl-devel
- gcc
- libxml2-devel
- libxslt-devel
- mysql
- mysql-devel
- python-devel
- python-setuptools
- python-simplejson (for the crepo tool)
- sqlite-devel
- MacOS (mac port):
- liblxml
- libxml2
- libxslt
- mysql5-devel
- simplejson (easy_install)
- sqlite3
You need to have crepo installed, and preferably on your path. If it is not on your path, set the environment variable
CREPO
to point tocrepo.py
from that distribution. You can clone crepo from http://github.com/cloudera/crepo.git somewhere else on your system.
To build and get the core server running:
$ export HADOOP_HOME=<path-to-hadoop-home> $ git clone http://github.com/cloudera/hue.git $ cd hue $ make apps $ build/env/bin/hue runserver_plus
To start the helper daemons:
$ build/env/bin/hue beeswax_server $ build/env/bin/hue jobsubd
Now Hue should be running on http://localhost:8000.
In order to start up a pseudo-distributed cluster with the plugins enabled, run:
$ ./tools/scripts/configure-hadoop.sh all
After doing so, running jps
should show all the daemons running (NN, JT,
TT, DN) and you should be able to see the web UI on http://localhost:50030/ and
http://localhost:50070/.
- 1: What does "Exception: no app!" mean?
Your template has an error in it. Check for messages from the server that look like:
INFO:root:Processing exception: Unclosed tag 'if'. Looking for one of: else, endif
- 2: What do I do if I get "There was an error launching ..."?
- Turn on debugging by issuing
dbug.cookie()
in a Firebug console.
If you need to name your urls
(http://docs.djangoproject.com/en/dev/topics/http/urls/#naming-url-patterns)
because there's ambiguity in the view, be sure to prefix the name
with the application name. The url name namespace is global. So
jobsub.list
is fine, but list
is not.
Hue is using Django 1.1, which supports the notion of URL namespaces: http://docs.djangoproject.com/en/dev/topics/http/urls/#url-namespaces. We have yet to move over our URLs to this construct. Brownie points for the developer who takes this on.
Right now, we check in the generated thrift code. To generate the code, you'll need the thrift binary. Compile it like so:
$ git clone http://github.com/dreiss/thrift.git $ cd thrift $ ./bootstrap.sh $ ./configure --with-py=no --with-java=no --with-perl=no --prefix=$HOME/pub
We exclude python, java, and perl because they don't like to install in prefix. If you look around at configure's --help, there are environment variables that determine where those runtime bindings are installed.
$ make && make install
When preparing .thrift
files, you can use she-bangs to generate
the python bindings like so:
#!/usr/bin/env thrift -r --gen py:new_style -o ../../../
Note
This file is in reStructuredText. You may run
rst2html README.rst > README.html
to produce a HTML.