"Python: Command Not Found" in Ubuntu 20.04LTS During Node Preparation

Problem Description

When initiating a pool with shipyard pool add, using the microsoft-azure-batch publisher 20-04-lts ubuntu image, the python executable is not available in the newly created node’s $PATH per Ubuntu’s new policy of handling the system python executable name and the 2-to-3 migration. Because nodeprep.sh references “python” as the executable name in a couple spots, the executable fails to be found, and the node preparation start task fails.

Batch Shipyard Version

shipyard, version 3.9.1

Steps to Reproduce

generate a pool with an ubuntu-server-container, microsoft-azure-batch, 20-04-lts image (shipyard pool add with a simple pool config for a single dedicated node)

Expected Results

Successful pool deploy

Actual Results

stderr.txt contains python:command not found (nodeprep.sh:385)

Redacted Configuration

pool.yaml

pool_specification:
  id: mypool
  vm_configuration:
    platform_image:
      offer: ubuntu-server-container
      publisher: microsoft-azure-batch
      sku: 20-04-lts
  vm_count:
    dedicated: 1
    low_priority: 0
  vm_size: STANDARD_A1_V2

Additional Logs

python:command not found (nodeprep.sh:385)

Additional Comments

This can be worked around by specifying a system python symlink in the additional_node_prep > pre commands. Happy to submit a pull request with changes to nodeprep.sh that test and direct to the appropriate python executable name to run so that the additional_node_prep pre-commands are no longer needed. I can always, of course, just pick a different image as well!

[alfpark]

Thanks for opening this issue. 20.04 isn’t supported yet, but will be in the next version.

[ecocarlisle]

If you enable unverified versions you can select the dvsm from Windows which is referenced in the Microsoft tutorials and the commands will work on startup.