Thanks for your replies.
When we are trying to install the openwisp server as discussed,we are using below playbook.yml
=============================================================
RUNNING HANDLER [openwisp.openwisp2-dev : reload supervisor] **********************************************************************************
changed: [139.59.18.30]
RUNNING HANDLER [openwisp.openwisp2-dev : remove celerybeat schedule] *************************************************************************
ok: [139.59.18.30]
TASK [openwisp.openwisp2-dev : migrate] *******************************************************************************************************
[WARNING]: Unable to use /var/www/.ansible/tmp as temporary directory, failing back to system: [Errno 13] Permission denied:
'/var/www/.ansible'
fatal: [139.59.18.30]: FAILED! => {"changed": false, "cmd": "./manage.py migrate --noinput", "msg": "\n:stderr: Traceback (most recent call last):\n File \"./manage.py\", line 10, in <module>\n execute_from_command_line(sys.argv)\n File \"/opt/openwisp2/env/lib/python3.7/site-packages/django/core/management/__init__.py\", line 419, in execute_from_command_line\n utility.execute()\n File \"/opt/openwisp2/env/lib/python3.7/site-packages/django/core/management/__init__.py\", line 395, in execute\n django.setup()\n File \"/opt/openwisp2/env/lib/python3.7/site-packages/django/__init__.py\", line 24, in setup\n apps.populate(settings.INSTALLED_APPS)\n File \"/opt/openwisp2/env/lib/python3.7/site-packages/django/apps/registry.py\", line 122, in populate\n app_config.ready()\n File \"/opt/openwisp2/env/lib/python3.7/site-packages/openwisp_controller/config/apps.py\", line 35, in ready\n self.__setmodels__()\n File \"/opt/openwisp2/env/lib/python3.7/site-packages/openwisp_controller/config/apps.py\", line 51, in __setmodels__\n 'subnet_division', 'SubnetDivisionRule'\n File \"/opt/openwisp2/env/lib/python3.7/site-packages/swapper/__init__.py\", line 80, in load_model\n \"Could not find {name}!\".format(name=join(app_label, model))\ndjango.core.exceptions.ImproperlyConfigured: Could not find subnet_division.SubnetDivisionRule!\n", "path": "/opt/openwisp2/env/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin", "syspath": ["/tmp/ansible_django_manage_payload_o7601lzv/ansible_django_manage_payload.zip", "/usr/lib/python36.zip", "/usr/lib/python3.6", "/usr/lib/python3.6/lib-dynload", "/usr/local/lib/python3.6/dist-packages", "/usr/lib/python3/dist-packages"]}
PLAY RECAP ************************************************************************************************************************************
139.59.18.30 : ok=79 changed=26 unreachable=0 failed=1 skipped=45 rescued=0 ignored=2
Appreciate your constant support.