OpenVZ template conversion fails: def writeconfig(configfile, configtext, configmode=0644)

Symptoms 

Conversion of OpenVZ template fails:

CONFIG_TEXT: File "/usr/libexec/ovz-template-converter", line 36
def writeconfig(configfile, configtext, configmode=0644):
^
SyntaxError: invalid token

Cause

Convertion script is not adopted for python36.

Resolution

1. Connect to OpenVZ node via SSH
2. Rename the script /usr/libexec/ovz-template-converter:

   # mv /usr/libexec/ovz-template-converter{,.orig}

3. Replace the script /usr/libexec/ovz-template-converter with the one from attachment:

   # cd /usr/libexec/
   # rm -f ovz-template-converter
   # wget -O ovz-template-converter https://raw.githubusercontent.com/solusvm-support/svm_patches/master/ovz-template-converter.patched
   # chmod +x /usr/libexec/ovz-template-converter

4. Install the package python36-pip:

   # yum install python36-pip

5. Install configobj module:

   # pip3 install configobj