Tiltfile

def min_k8s_version(min_version):
    version_str = _get_server_version()
    cur_ver = _version_tuple(version_str)
    min_ver = _version_tuple(min_version)
    
    if cur_ver < min_ver:
        print(" ---------------------------------------------------------- ")
        print("|                                                          |")
        print("|            Minimum Kubernetes Version Not Met!           |")
        print("|                Current Version : v{}                 |".format(version_str))
        print("|            Minimum Required Version : v{}            |".format(min_version))
        print("|            Current Kubernetes Cluster : {}         |".format( k8s_context()))
        print("|                                                          |")
        print(" ---------------------------------------------------------- ")
        fail('Minimum Kubernetes Version Not Met! Current Version is %s' % version_str)

def max_k8s_version(max_version):
    version_str = _get_server_version()
    cur_ver = _version_tuple(version_str)
    max_ver = _version_tuple(max_version)
    
    if cur_ver > max_ver:
        print(" ---------------------------------------------------------- ")
        print("|                                                          |")
        print("|            Maximum Kubernetes Version Not Met!           |")
        print("|                Current Version : v{}                 |".format(version_str))
        print("|            Maximum Required Version : v{}            |".format(max_version))
        print("|            Current Kubernetes Cluster : {}         |".format( k8s_context()))
        print("|                                                          |")
        print(" ---------------------------------------------------------- ")
        fail('Maximum Kubernetes Version Not Met! Current Version is %s' % version_str)


def _get_server_version():
    # This relies on the fact that the shell command returning something in the
    # form 'Server Version: vX.X.X'.
    #
    # The previous version used 'grep' to filter out the server version. Use a
    # native way to support systems without 'grep'.
    kubectl_version_output = str(local('kubectl version', quiet=True))
    for line in kubectl_version_output.split('\n'):
        if line.startswith('Server Version'):
            version_string = line.split(':')[1].strip()
            if version_string.startswith('version.Info'):
               # we are pre 1.28 kubectl, let's use the old method
               return _get_server_version_pre_1_28_kubectl()
            else:
               return version_string.replace('v', '')
            
    return ""

def _get_server_version_pre_1_28_kubectl():   
    kubectl_version_output = str(local('kubectl version --short', quiet=True))
    version_str = ''
    for line in kubectl_version_output.split('\n'):
        if line.startswith('Server Version'):
            version_str = line
            break
    # Get the string, separate it at the colon, remove the 'v' and any spaces.
    return version_str.split(':')[1].replace('v','').strip()


def _version_tuple(v):
  # splits a string into a list of contiguous numeric and non-numeric parts, and makes the numeric parts ints, e.g.:
  # _version_tuple("1.2020.3-beta.2") == [1, ".", 2020, ".", 3, "-beta.", 2]
  # this allows version comparison such that "1.10" > "1.9"

  ret = []
  if len(v) == 0:
    return ret

  cur_part_is_number = v[0].isdigit()
  cur_part = ''
  for c in v.elems():
    if c.isdigit() != cur_part_is_number:
      if cur_part.isdigit():
        ret.append(int(cur_part))
      else:
        ret.append(cur_part)
      cur_part = ''
      cur_part_is_number = c.isdigit()
    cur_part += c

  if cur_part.isdigit():
    ret.append(int(cur_part))
  else:
    ret.append(cur_part)

  return ret