is_vm_supported_for_extension.py

#!/usr/bin/env python
import os
import os.path
import platform

def is_vm_supported_for_extension():
    """
    Checks if the VM this extension is running on is supported by OMSAgent
    Returns for platform.linux_distribution() vary widely in format, such as
    '7.3.1611' returned for a VM with CentOS 7, so the first provided
    digits must match
    The supported distros of the OMSAgent-for-Linux are allowed to utilize
    this VM extension. All other distros will get error code 51
    """
    supported_dists = {'redhat' : ['6', '7', '8'], 'red hat' : ['6', '7', '8'], 'rhel' : ['6', '7', '8'], # Red Hat
                       'centos' : ['6', '7', '8'], # CentOS
                       'oracle' : ['6', '7', '8'], 'ol': ['6', '7', '8'], # Oracle
                       'debian' : ['8', '9'], # Debian
                       'ubuntu' : ['14.04', '16.04', '18.04', '20.04'], # Ubuntu
                       'suse' : ['12', '15'], 'sles' : ['12', '15'], # SLES
                       'amzn' : ['2'] # AWS
    }

    vm_dist, vm_ver, vm_supported = '', '', False

    try:
        print("platform.linux_distribution()=", platform.linux_distribution())
        vm_dist, vm_ver, vm_id = platform.linux_distribution()
    except AttributeError:
        try:
            print("platform.dist()=", platform.dist())
            vm_dist, vm_ver, vm_id = platform.dist()
        except AttributeError:
            print("Falling back to /etc/os-release distribution parsing")

    # Fallback if either of the above fail; on some (especially newer)
    # distros, linux_distribution() and dist() are unreliable or deprecated
    if not vm_dist and not vm_ver:
        try:
            print("opening /etc/os-release")
            with open('/etc/os-release', 'r') as fp:
                for line in fp:
                    print(line)
                    if line.startswith('ID='):
                        vm_dist = line.split('=')[1]
                        vm_dist = vm_dist.split('-')[0]
                        vm_dist = vm_dist.replace('\"', '').replace('\n', '')
                    elif line.startswith('VERSION_ID='):
                        vm_ver = line.split('=')[1]
                        vm_ver = vm_ver.replace('\"', '').replace('\n', '')
            print("parsed string from /etc/os-release: vm_dist=", vm_dist, "vm_ver=", vm_ver)
        except:
            return vm_supported, 'Indeterminate operating system', ''

    # Find this VM distribution in the supported list
    for supported_dist in list(supported_dists.keys()):
        if not vm_dist.lower().startswith(supported_dist):
            continue

        # Check if this VM distribution version is supported
        vm_ver_split = vm_ver.split('.')
        for supported_ver in supported_dists[supported_dist]:
            supported_ver_split = supported_ver.split('.')

            # If vm_ver is at least as precise (at least as many digits) as
            # supported_ver and matches all the supported_ver digits, then
            # this VM is guaranteed to be supported
            vm_ver_match = True
            for idx, supported_ver_num in enumerate(supported_ver_split):
                try:
                    print("idx=", idx, "supported_ver_num=", supported_ver_num)
                    supported_ver_num = int(supported_ver_num)
                    print("vm_ver_split[idx]=", vm_ver_split[idx])
                    vm_ver_num = int(vm_ver_split[idx])
                except IndexError:
                    vm_ver_match = False
                    break
                if vm_ver_num is not supported_ver_num:
                    vm_ver_match = False
                    break
            if vm_ver_match:
                vm_supported = True
                break

        if vm_supported:
            break

    return vm_supported, vm_dist, vm_ver


print(is_vm_supported_for_extension())