Delete ddn-exascaler filesystem module reference blueprints

[sudheer-quad]

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[gemini-code-assist]

Summary of Changes

Hello @sudheer-quad, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request focuses on removing the deprecated DDN EXAScaler filesystem module and all its associated components from the repository. The removal encompasses the module's core Terraform files, documentation, and all related testing and deployment blueprints and configurations. This change is a direct consequence of the module's deprecation, aiming to simplify the project structure and eliminate unsupported elements, guiding users towards actively maintained solutions.

Highlights

• DDN EXAScaler Module Removal: The entire community/modules/file-system/DDN-EXAScaler module, including its Terraform configurations, variables, outputs, and documentation, has been removed from the repository. This action aligns with the module's deprecation notice, which indicated its planned removal by July 1, 2025.
• Associated Test Infrastructure Deleted: All related test infrastructure for the DDN EXAScaler module has been deleted. This includes Ansible playbooks for Lustre testing with Slurm and VMs, as well as Cloud Build blueprints and test configurations that referenced the deprecated module.
• Codebase Streamlining: This cleanup streamlines the codebase by removing an unsupported and deprecated file system module, reducing maintenance overhead and focusing resources on recommended alternatives like the GCP Managed Lustre module.

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[gemini-code-assist]

Code Review

This pull request removes the deprecated DDN-EXAScaler filesystem module, along with its associated documentation, Terraform code, and test files. This is a good step towards cleaning up the codebase.

However, the removal appears to be incomplete. I've found several lingering references to the DDN-EXAScaler module in files that were not modified in this pull request. Leaving these references will lead to broken links and potentially failing deployments for users who try to use examples that reference the deleted module.

Please update the following files to remove all references to DDN-EXAScaler:

• docs/network_storage.md: This file still contains links and compatibility information for the DDN-EXAScaler module.
• examples/hpc-enterprise-slurm.yaml: This example blueprint still attempts to use the community/modules/file-system/DDN-EXAScaler module.

Addressing these dangling references is critical to ensure a clean removal of the deprecated module.

[aslam-quad]

/gcbrun

[aslam-quad]

/gcbrun

[cboneti]

I left several comments, but not in every test file.
Directionally, I would like us to assess when we should replace ddn exascaler for managed lustre, versus removing the example. Furthermore, the testing coverage of managed lustre must be the same or superior to the unmanaged version. Please review the tests.

[cboneti]

this should remain since we want to keep the lustre vm example, right?

[sudheer-quad]

Currently, managed lustre vm is not configured with the above test validation.

[cboneti]

here: https://github.com/GoogleCloudPlatform/cluster-toolkit/blob/main/tools/cloud-build/daily-tests/tests/pfs-managed-lustre-vm.yml#L27, we should have:

• test-validation/test-mounts.yml
• test-validation/test-lustre-vm.yml

[cboneti]

I left a few new comments.

[cboneti]

same comment as exascaler-existing-vpc

[cboneti]

Please feel free to reassign this PR to me when you feel it is ready to review again.

[aslam-quad]

/gcbrun

[cboneti]

I have done another round of reviews, resolved old comments and add a few new comments, PTAL.

[cboneti]

here: https://github.com/GoogleCloudPlatform/cluster-toolkit/blob/main/tools/cloud-build/daily-tests/tests/pfs-managed-lustre-vm.yml#L27, we should have:

• test-validation/test-mounts.yml
• test-validation/test-lustre-vm.yml

[kadupoornima]

/gcbrun

[cboneti]

This code was in the internal, test-only blueprint: tools/cloud-build/daily-tests/blueprints/lustre-vm.yaml. It is ok to have test code in the internal blueprint, but I would not leave it here, in a public blueprint. It is confusing as it serves no practical purpose for our customers.
I recommend removing this startup script from here and then change tools/cloud-build/daily-tests/ansible_playbooks/test-validation/test-managed-lustre-vm.yml to do another meaningful test. For instance, something like this (untested), it could be added to slurm (in addition to current test) and vms. This is a full playbook, you might need to use just the tasks...

- name: Lustre Integration Test
  hosts: lustre_clients
  vars:
    mount_point: "/lustre"
    test_file: "{{ mount_point }}/ansible_test_{{ 9999 | random }}.txt"
  
  tasks:
    # 1. Magic Number Check
    - name: Verify Filesystem Type
      ansible.builtin.command: stat -f -c %T "{{ mount_point }}"
      register: fs_type
      changed_when: false
      failed_when: fs_type.stdout != 'lustre'

    # 2. Write Test (Canary File)
    - name: Write Canary File to Lustre
      ansible.builtin.copy:
        content: "Lustre Write Test Successful"
        dest: "{{ test_file }}"

    # 3. Read Test (Verify Content)
    - name: Read Canary File
      ansible.builtin.slurp:
        src: "{{ test_file }}"
      register: file_content

    - name: Assert Content Matches
      ansible.builtin.assert:
        that:
          - "file_content['content'] | b64decode == 'Lustre Write Test Successful'"

    # 4. Cleanup
    - name: Remove Canary File
      ansible.builtin.file:
        path: "{{ test_file }}"
        state: absent