Automating Your Experimentation

Once you have developed your experiment and set everything up, you may want to automate that setup so you can easily re-run the experimetn later. There are multiple ways to automate your experiment.

Scripting

You can write scripts using languages like Bash and Python to run commands on your nodes in a given scenario. For example, if you wanted to ping B from A and then ping A from B, in an experiment called test and project Share, you could write the following script in bash:

    ssh A.test.Share "ping -c 1 B"
    ssh B.test.Share "ping -c 1 A"

You can then save it, e.g., in a file called ping.sh and run it by typing on users.deterlab.net:

    bash ping.sh

Similarly, in Python you can achieve the same with the following script:

    import paramiko
    ssh = paramiko.SSHClient()
    ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    ssh.connect("A.test.Share")

    stdin, stdout, stderr = ssh.exec_command("ping -c 1 B")
    ssh.connect("B.test.Share")

    stdin, stdout, stderr = ssh.exec_command("ping -c 1 A")

You can then save it, e.g., in a file called ping.py and run it on one of your experiment nodes (not on users.deterlab.net) by typing:

    python ping.py

DEW

You can use DEW - distributed experiment workflows to design your experiment in a human-readable format and generate NS file and bash scripts. `

We provide more guidance in DEW YouTube channel as well as in documentation on DEW Web site.

If you use image Ubuntu-DEW on your nodes, all the commands you type and snippets of their outputs will be saved in your project directory. You can use the tool flight_log, which is automatically installed in that image, to remind yourself of the commands you ran in the past and to select those you want to include in a Bash script. The script will be automatically generated for you. More information about this direction is in DEW YouTube channel.

Orchestrator

You can use our MAGI orchestrator to create scripts that will be more robust and readable than Bash scripts. Please see our orchestrator documentation for guidelines and examples.