functions.py

# Handy function that executes an external command in the shell
# and returns 3 values: exit code of the command, its standard output
# and its error output.
# If you run the script directly, an example is provided:
# first it will run a successful command and then one with errors
# (you may want to modify them if not running a Unix system).

#std_out data type is str

import subprocess

def runcommand (cmd):
    try:
      proc = subprocess.Popen(cmd,
                              stdout=subprocess.PIPE,
                              stderr=subprocess.PIPE,
                              shell=True,
                              universal_newlines=True)
      std_out, std_err = proc.communicate()
      return proc.returncode, std_out, std_err
    except:
      print("Something went wrong while trying to execute command:",cmd) 

def output_command(cmd,exit_program="False",print_error="True"):
    code, stdout, err = runcommand(cmd)
    if print_error=="True" and code!=0:
      print("-----------------------------------------------------------------")
      print(f"For the command: {cmd} \nThe error is : {err}")
      print("-----------------------------------------------------------------")
    if exit_program == "True" and code!=0:
      exit()
      ##Convert str output to list
    return stdout.split(" ")

def look_for_other_nfs_servers(ip_parameter):
    cmd="kubectl get pv -o jsonpath='{.items[?(@.status.phase==\"Bound\")].spec.nfs.server}'"
    ip_list= output_command(cmd)
    print("---------------------------------------------------------------------------- ")
    print("Now looking for NFS server other than ",ip_parameter," with PVs in Bound state")
    auxiliaryList=[]
    for ip in ip_list:
      if ip != ip_parameter:
        if ip not in auxiliaryList:
          auxiliaryList.append(ip)
          print(f"Found: {ip}, that is not the given NFS server {ip_parameter}. PLZ CHECK IT!")
          ip_quotes=f'"{ip}"'
          expression1="kubectl get pv -o jsonpath='{.items[?(@.spec.nfs.server=="
          expression2=')].metadata.name}\''
          cmd2=expression1+ip_quotes+expression2
          pv_list= output_command(cmd2)
          print(f"List of PVs in status BOUND for NFS server {ip} is {pv_list}")
    if len(auxiliaryList)== 0:
      print("No other NFS servers found.")
    print("---------------------------------------------------------------------------- ")
        

def write_to_a_file(content):
    f = open("counter.txt", "w")
    f.write(f"{str(content)}")
    f.close()
        


def main():
    #look_for_other_nfs_servers("1.2.3.4")
    #command="ls -la"
    #list = output_command(command)
    #print(list)
    #print("==================================================");
    #print('Running "ls -lh"...');
    #print("==================================================");
    #code, out, err = runcommand("ls -lh");
    #print("Return code: {}".format(code));
    #print("--------------------------------------------------");
    #print("stdout:");
    #print(out);
    #print("--------------------------------------------------");
    #print("stderr:");
    #print(err);
    #print("--------------------------------------------------");

    #print("==================================================");
    #print('Running "ls -lj"...');
    #print("==================================================");
    #code, out, err = runcommand("ls -lj");
    #print("Return code: {}".format(code));
    #print("--------------------------------------------------");
    #print("stdout:");
    #print(out);
    #print("--------------------------------------------------");
    #print("stderr:");
    #print(err);
    #print("--------------------------------------------------");
    write_to_a_file(6665)
    
if __name__ == '__main__':
    main()