ASE Pre-Registration Script

ASEPreRegistration.py

import argparse
import sys 
import grp
import pwd
import subprocess
import os
import json

class PreRegistration:

    def __init__(self, args = None):
        self.args = args
        self.osGroup = 'msawb'
        self.homePath = '/opt/msawb'
        self.tmpDirPath = '{0}/tmp'.format(self.homePath)
        self.configDirectory = '{0}/etc/config/SAPAse'.format(self.homePath)
        self.configFile = '{0}/config.json'.format(self.configDirectory)
        self.getDbPasswordFile = '{0}/GetDbPassword.sh'.format(self.configDirectory)
        self.sidUser = ''
        self.sid = ''
        self.dbPort = 4901
        self.dbUser = 'sapsa'
        self.dbPasswordUtil = ''

    def run(self):
        self.ShowBanner()
        self.GetUserInputs()
        
        print("+ Setting up OS users and groups")
        self.CreateOSGroup(self.osGroup)
        self.AddUserToGroup(self.sidUser, self.osGroup)

        print("+ Setting up directories and permissions")
        self.CreateDirectory(self.configDirectory)
        self.ChangeOwner(self.homePath, 'root', self.osGroup)
        self.CreateDirectory(self.tmpDirPath)
        self.ChangeOwner(self.tmpDirPath, 'root', self.osGroup)
        self.ChangeMod(self.tmpDirPath, 0o777)

        print("+ Creating GetDbPassword script file".format(self.getDbPasswordFile))
        self.CreateFile(self.getDbPasswordFile)

        print("+ Setting up permissions for GetDbPassword script file")
        self.ChangeOwner(self.getDbPasswordFile, 'root', self.osGroup)
        self.ChangeMod(self.getDbPasswordFile, 0o650) # Not a type. Its 650 in Octal : 0o650

        print("+ Creating config file".format(self.configFile))
        self.CreateFile(self.configFile)

        print("+ Setting up permissions for config file")
        self.ChangeOwner(self.configFile, 'root', self.osGroup)
        self.ChangeMod(self.configFile, 0o640) # Not a type. Its 640 in Octal : 0o640
        
        print("+ Setting up initial configurations")
        self.SetupInitialConfigurationSettings()

        print("\n** The necessary stuffs are configured. Please return to Azure portal/PS/CLI to now select the backup policy and enable protection for these SAP ASE DBs **\n")

    """
    Display a banner
    """
    def ShowBanner(self):
        print (3 * "\n")
        print (57 * '-')
        print ("   A Z U R E - B A C K U P   R E G I S T R A T I O N")
        print (57 * '-')
        print("\n** This script is used to configure necessary permissions for Azure Backup to be able to backup and restore SAP ASE DBs within this SAP system. ** \n")

    """
    See if all input params are set through command line. If anything param is missing ask user for input
    """
    def GetUserInputs(self):
        try: input = raw_input
        except NameError: pass
        
        if self.args.sid:
            self.sid = self.args.sid
        else:
            self.sid = input("\n Enter the instance name of the ASE System: ")
            if not self.sid:
                raise Exception("No value received. Aborting.")

            self.sidUser = input("\n Enter OS Username under which ASE System runs (e.g. syb<sid>): ")
            if not self.sidUser:
                raise Exception("No value received. Aborting.")

            self.dbHostName = input("\n Enter the Hostname of the ASE System (e.g. localhost): ")
            if not self.dbHostName:
                raise Exception("No value received. Aborting.")

            self.dbUser = input("\n Enter the ASE Database Username to be used for ODBC Connection (e.g. sapsa): ")
            if not self.dbUser:
                raise Exception("No value received. Aborting.")

            self.dbPort = input("\n Enter the Port Number of the ASE Database System (e.g. 4901): ")
            if not self.dbPort:
                raise Exception("No value received. Aborting.")

            self.dbPasswordUtil = input("\n Enter dpsp utility command to retrieve ASE Database Password: ")
            if not self.dbPasswordUtil:
                raise Exception("No value received. Aborting.")
            print (2 * "\n")

    """
    Helper method to create an OS group. Skips creation if group already exists.
    """
    def CreateOSGroup(self, groupName):
        try:
            # Check if group exists
            grp.getgrnam(groupName)
        except KeyError:
            # Group doesn't exists. Creating group
            subprocess.check_call(["/usr/sbin/groupadd", groupName])

    """
    Helper method to add any OS user to any OS group
    """
    def AddUserToGroup(self, userName, groupName):
        try:
            pwd.getpwnam(userName)
        except KeyError:
            raise Exception("\n User {0} doesn't exists.".format(userName))

        subprocess.check_call(["/usr/sbin/usermod", "-a", "-G", groupName, userName])

    """
    Helper method to chown any file/directory
    """
    def ChangeOwner(self, path, userName, groupName):
        os.chown(path, pwd.getpwnam(userName).pw_uid, grp.getgrnam(groupName).gr_gid)

    """
    Helper method to create a directory if not exists
    """
    def CreateDirectory(self, directoryPath):
        if os.path.exists(directoryPath) and os.path.isdir(directoryPath):
            pass
        else:
            os.makedirs(directoryPath)

    """
    Helper method to create a file if not exists
    """
    def CreateFile(self, filePath):
        if os.path.exists(filePath) and os.path.isfile(filePath):
            pass
        else:
            open(filePath, 'a').close()

    """
    Helper method to chmod any file/directory
    """
    def ChangeMod(self, path, permMask):
        os.chmod(path, permMask)

    """
    Helper method to configure config file with config object and initial values.
    """
    def SetupInitialConfigurationSettings(self):
        config = [{
            "LogicalContainerId": self.sid,
            "LogicalContainerOSUser": self.sidUser,
            "PropertyBag": dict(dbHostName= self.dbHostName, dbPort = self.dbPort, dbUser = self.dbUser, dbPasswordUtil = 'sh ' + self.getDbPasswordFile)
        }]
        with open(self.configFile, "w") as f:
            f.write(json.dumps(config, indent = 4, sort_keys = True))
        with open(self.getDbPasswordFile, "w") as f:
            f.write('#!/bin/bash\nsource ~/SYBASE.sh && unset LANG && ' + self.dbPasswordUtil)

if __name__ == '__main__':
    if os.getuid() != 0:
        print("This script requires admin rights. Please execute this script as root or with sudo.")
        sys.exit(1)

    parser = argparse.ArgumentParser(description='Configure a machine for running Azure Backup')
    # parser.add_argument('-u', dest='unattend', help='Run the script in unattend mode', action='store_true', default=False)
    parser.add_argument('--sid', help='The instance name of the ASE System')

    PreRegistration(parser.parse_args()).run()