Install .NET 4

install_dotnet.py

def regsearch(regpath):
    r = wmi.Registry ()
    result, names = r.EnumKey (
      hDefKey=_winreg.HKEY_LOCAL_MACHINE,
      sSubKeyName="SOFTWARE\Microsoft\NET Framework Setup\NDP"
    )
    return names    
    
''' Confirm that .Net4 and the required security patch are installed
This is a really crappy check, we're pulling a list of .NET versions 
from the registry and checking the version number''' 
def dotnet():
    dotnetchk = 0
    names = regsearch("SOFTWARE\Microsoft\NET Framework Setup\NDP")
    for key in names:
        version = key.split('.')
        if version[0] == "v4":
            dotnetchk += 1
            break
    if dotnetchk == 0:
        downfile(workdir + "\\PreReqs\\", 'http://download.microsoft.com/download/9/5/A/95A9616B-7A37-4AF6-BC36-D6EA96C8DAAE/dotNetFx40_Full_x86_x64.exe')
        logging.info("Installing .NET 4")
        subprocess.check_call(workdir + "\\PreReqs\\dotNetFx40_Full_x86_x64.exe /norestart /quiet")
        logging.info(".NET 4 installed")
        downfile(workdir + "\\PreReqs\\", 'http://download.microsoft.com/download/1/3/C/13CB303A-1D97-41BC-ADAC-137CBC8FF59A/NDP40-KB2656351-x64.exe')
        logging.info("Installing .NET 4 Security Patch")
        subprocess.check_call(os.getcwd() + "\\PreReqs\\NDP40-KB2656351-x64.exe /norestart /quiet")
        logging.info(".Net 4 Security Patch Installed")
    else:
        logging.info(".Net 4 already installed, checking if security update is installed")
        hotfixchk = 0    
        names = regsearch("SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall")
        for hotfix in names:
            if "KB2656351" in hotfix:
                hotfixchk += 1
                break
        if hotfixchk > 0:
            downfile(workdir + "\\PreReqs\\", 'http://download.microsoft.com/download/1/3/C/13CB303A-1D97-41BC-ADAC-137CBC8FF59A/NDP40-KB2656351-x64.exe')
            subprocess.check_call(os.getcwd() + "\\PreReqs\\NDP40-KB2656351-x64.exe /norestart /quiet")
            logging.info(".Net 4 Security Patch successfully Installed")
        else:
            logging.info(".Net 4 Security Patch not needed!")
            
'''Download a file, if we get a text file we check if it's a META url redirect and handle it'''
def downfile(downdir, url):
    req = urllib2.Request(url)
    req.add_header('User-Agent', 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.9.0.3) Gecko/2008092417 Firefox/3.0.3')
    response = urllib2.urlopen(req)
    urlsplit = os.path.split(url)
    file_name = urlsplit[1]
    if response.info().getheader('Content-Type') == 'text/html':
        link=response.read()
        response.close()
        file_name = re.search('URL=(.*)">', link).group(1)
        url = urlsplit[0] + '/' + file_name
    if os.path.exists(downdir+file_name):
        logging.info(file_name + " exists, so why download it?")
    else:
        logging.info('Downloading ' + file_name)
        f = open(downdir+file_name, 'wb')
        u = urllib2.urlopen(url)
        meta = u.info()
        file_size = int(meta.getheaders("Content-Length")[0])
        print "Downloading: %s Bytes: %s" % (file_name, file_size)
        
        file_size_dl = 0
        block_sz = 8192
        while True:
            buffer = u.read(block_sz)
            if not buffer:
                break
        
            file_size_dl += len(buffer)
            f.write(buffer)
            status = r"%10d Bytes  [%3.2f%%]" % (file_size_dl, file_size_dl * 100. / file_size)
            status = status + chr(8)*(len(status)+1)
            print status,
        
        f.close()
    return file_name