Lux scripts by nature are a simple way to move from manual testing to
consistent, repeatable, and automated testing while keeping time to write tests
to a minimum. A little or no experience is required to start. However,
understanding some basic regular expression patterns will benefit you.
Firstly, you need to collect some raw input and output strings to transform them
into a Lux script. For example, connect to a host and do a manual test as you
do before.
ssh rt | tee log.txt
Next, you can easily create a Lux script by editing log.txt (not shown for
brevity) by marking send and receive strings with prefixes and cutting down
insignificant parts of the output. ! means send a line (command), ? is
expected output regexp match, and ??? is expected output exact match. Pretty
simple.
An example above does some basic tricks:
- Decorate stdout and logs outputs (lines 2, 6, 21)
- Start a new shell
shell1(line 4) - Connect to the host
rt(line 7), and wait for a regular expression to match (regexp ‘.*’ means any character, followed by a hash as a privileged level prompt ending, line 8) - Turn off pagination and execute “show version” command (lines 9, 11)
- Check that outputs contain 16.12.04 IOS version, UNIVERSALK9_IAS-M image reference, and on followed lines configuration register is 0x2102 (lines 12-16)
- Ping cisco.com, expecting 100% success rate (lines 18, 19)
To run a test case:
lux example1.lux
Lux shows a progress report during tests run on stdout. In case of any
unexpected results, the test will fail, showing a brief explanation of what was
sent and what was received from the device under test. More detailed log files
will be available for further troubleshooting.
For more on Lux features, like regular expressions support, switching between
multiple concurrent sessions, extensive logging, post mortem analysis,
debugging, and more, check the
official documentation.
lux-colorizer, Lux Syntax Highlight VS Code Extension
Each Lux script may have hundreds+ of send/expect lines and comments, which
are hard to read and work with. The extension significantly increases
readability and visually distinguishes input and output streams, keywords,
comments, meta statements, special characters and variables. This simplification
will help test writers to produce test in a more structured format and see
syntax errors early before run, increasing the speed of writing, reviewing, and
maintaining test scripts.
Related Sandbox
Cisco DevNet organization provides a great selection of always-on and reservation-based sandboxes to test different solutions, products, and APIs, including Cisco NSO.
Unfortunately, existing NSO sandboxes don’t have lux package installed, to the best
of my knowledge. Moreover, users cannot add lux package themselves due to
security policies. To use lux user have to build own environment and install
lux using standard
installation guidelines.