Hi Bence, In addition to your comment: On the other hand the train release is still supposed to work with python2, so that maybe a workaround until calico makes the changes mentioned by Neil above. Looks like there is no workarounds for calico beginning from Stein! The other hand is to wait ages for calico python3 support or try to find the alternatives. In May 2020 we already will have Ussuri and Calico is still not in Stein. I tried to install Stein or Train and I see that neutron is already based python3. You have some proper way/guyide how you can install neutron in stein release by using python2.7? Stein and Train components are essentially written on python3 in those releases. Looks like its nothing to do with the components which are already written on python3 on those releases. I asked today the community about that, let's wait a few days for the answer: https://ask.openstack.org/en/question/125627/is-it-possible-to-install-openstack-stein-or-train-with-python-27-and-not-default-python3/ Meanwhile you can see some notes about it: TRAIN https://wrestlingpenguins.wordpress.com/2019/10/23/openstack-train-for-ubuntu-18-04-lts/ STEIN https://javacruft.wordpress.com/2019/04/17/openstack-stein-for-ubuntu-18-04-lts/ Rocky is the last guy who still based on python2.7 code. ROCKY https://wrestlingpenguins.wordpress.com/2018/09/07/openstack-rocky-for-ubuntu-18-04-lts/ From the research found: 1. While running neutron installation on stein it uses python3 packages: add-apt-repository cloud-archive:stein root@qtor-ctr101:~# apt install neutron-server Reading package lists... Done Building dependency tree Reading state information... Done The following additional packages will be installed: alembic docutils-common ieee-data ipset javascript-common libipset3 libjbig0 libjpeg-turbo8 libjpeg8 libjs-jquery libjs-sphinxdoc libjs-underscore liblcms2-2 libpaper-utils libpaper1 libtiff5 libwebp6 libwebpdemux2 libwebpmux3 neutron-common neutron-plugin-ml2 pycadf-common python-babel-localedata python-pastedeploy-tpl python3-alembic python3-amqp python3-anyjson python3-appdirs python3-asn1crypto python3-babel python3-blinker python3-bs4 python3-cachetools python3-certifi python3-cffi python3-cffi-backend python3-chardet python3-cliff python3-cmd2 python3-contextlib2 python3-crypto python3-cryptography python3-dateutil python3-debtcollector python3-decorator python3-deprecation python3-designateclient python3-distutils python3-dnspython python3-docutils python3-dogpile.cache python3-eventlet python3-extras python3-fasteners python3-fixtures python3-funcsigs python3-futurist python3-greenlet python3-html5lib python3-httplib2 python3-idna python3-iso8601 python3-jinja2 python3-jmespath python3-json-pointer python3-jsonpatch python3-jsonschema python3-jwt python3-keyring python3-keyrings.alt python3-keystoneauth1 python3-keystoneclient python3-keystonemiddleware python3-kombu python3-lib2to3 python3-linecache2 python3-logutils python3-lxml python3-mako python3-markupsafe python3-memcache python3-migrate python3-mimeparse python3-monotonic python3-msgpack python3-munch python3-netaddr python3-netifaces python3-neutron python3-neutron-lib python3-neutronclient python3-novaclient python3-oauthlib python3-olefile python3-openssl python3-openstacksdk python3-openvswitch python3-os-client-config python3-os-ken python3-os-service-types python3-os-traits python3-os-xenapi python3-osc-lib python3-oslo.cache python3-oslo.concurrency python3-oslo.config python3-oslo.context python3-oslo.db python3-oslo.i18n python3-oslo.log python3-oslo.messaging python3-oslo.middleware python3-oslo.policy python3-oslo.privsep python3-oslo.reports python3-oslo.rootwrap python3-oslo.serialization python3-oslo.service python3-oslo.upgradecheck python3-oslo.utils python3-oslo.versionedobjects python3-osprofiler python3-ovsdbapp python3-paramiko python3-paste python3-pastedeploy python3-pastescript python3-pbr python3-pecan python3-pil python3-pkg-resources python3-ply python3-posix-ipc python3-prettytable python3-psutil python3-pyasn1 python3-pycadf python3-pycparser python3-pygments python3-pyinotify python3-pymysql python3-pyparsing python3-pyperclip python3-pyroute2 python3-repoze.lru python3-requests python3-requestsexceptions python3-rfc3986 python3-roman python3-routes python3-secretstorage python3-setproctitle python3-setuptools python3-simplegeneric python3-simplejson python3-singledispatch python3-six python3-sortedcontainers python3-sqlalchemy python3-sqlalchemy-ext python3-sqlparse python3-statsd python3-stevedore python3-tempita python3-tenacity python3-testresources python3-testscenarios python3-testtools python3-tinyrpc python3-traceback2 python3-tz python3-unicodecsv python3-unittest2 python3-urllib3 python3-vine python3-waitress python3-webencodings python3-webob python3-webtest python3-wrapt python3-yaml sgml-base xml-core Suggested packages: apache2 | lighttpd | httpd liblcms2-utils python3-editor python-amqp-doc python-blinker-doc python3-dev python-cliff-doc python-crypto-doc python-cryptography-doc python3-cryptography-vectors python-debtcollector-doc docutils-doc fonts-linuxlibertine | ttf-linux-libertine texlive-lang-french texlive-latex-base texlive-latex-recommended python-eventlet-doc python-funcsigs-doc python-futurist-doc python-greenlet-doc python-greenlet-dev python3-greenlet-dbg python3-genshi python-jinja2-doc gnome-keyring libkf5wallet-bin gir1.2-gnomekeyring-1.0 python-keystoneauth1-doc python3-requests-kerberos python-kombu-doc python3-boto python3-django python3-pymongo python3-redis python3-lxml-dbg python-lxml-doc python3-beaker python-mako-doc memcached python-migrate-doc ipython3 python-netaddr-docs python-neutron-lib-doc python-openssl-doc python3-openssl-dbg python-openstacksdk-doc python-os-client-config-doc python-os-service-types-doc python-os-traits-doc python-os-xenapi-doc python-osc-lib-doc python-oslo.cache-doc python-oslo.concurrency-doc python-oslo.log-doc python3-confluent-kafka python-oslo.middleware-doc python-oslo.policy-doc python-oslo.privsep-doc python-oslo.reports-doc python-oslo.service-doc python-oslo.versionedobjects-doc python-ovsdbapp-doc python3-gssapi httpd-wsgi libapache2-mod-python libapache2-mod-scgi libjs-mochikit python3-cherrypy3 python-pecan-doc python-pil-doc python3-pil-dbg python-ply-doc python-psutil-doc ttf-bitstream-vera python-pyinotify-doc python-pymysql-doc python-pyparsing-doc python-pyroute2-doc python3-socks python-secretstorage-doc python-setuptools-doc python-sortedcontainers-doc python-sqlalchemy-doc python3-psycopg2 python3-mysqldb python3-fdb python-sqlparse-doc python-tenacity-doc python-testtools-doc python-tinyrpc-doc python-waitress-doc python-webob-doc python-webtest-doc sgml-base-doc debhelper The following NEW packages will be installed: alembic docutils-common ieee-data ipset javascript-common libipset3 libjbig0 libjpeg-turbo8 libjpeg8 libjs-jquery libjs-sphinxdoc libjs-underscore liblcms2-2 libpaper-utils libpaper1 libtiff5 libwebp6 libwebpdemux2 libwebpmux3 neutron-common neutron-plugin-ml2 neutron-server pycadf-common python-babel-localedata python-pastedeploy-tpl python3-alembic python3-amqp python3-anyjson python3-appdirs python3-asn1crypto python3-babel python3-blinker python3-bs4 python3-cachetools python3-certifi python3-cffi python3-cffi-backend python3-chardet python3-cliff python3-cmd2 python3-contextlib2 python3-crypto python3-cryptography python3-dateutil python3-debtcollector python3-decorator python3-deprecation python3-designateclient python3-distutils python3-dnspython python3-docutils python3-dogpile.cache python3-eventlet python3-extras python3-fasteners python3-fixtures python3-funcsigs python3-futurist python3-greenlet python3-html5lib python3-httplib2 python3-idna python3-iso8601 python3-jinja2 python3-jmespath python3-json-pointer python3-jsonpatch python3-jsonschema python3-jwt python3-keyring python3-keyrings.alt python3-keystoneauth1 python3-keystoneclient python3-keystonemiddleware python3-kombu python3-lib2to3 python3-linecache2 python3-logutils python3-lxml python3-mako python3-markupsafe python3-memcache python3-migrate python3-mimeparse python3-monotonic python3-msgpack python3-munch python3-netaddr python3-netifaces python3-neutron python3-neutron-lib python3-neutronclient python3-novaclient python3-oauthlib python3-olefile python3-openssl python3-openstacksdk python3-openvswitch python3-os-client-config python3-os-ken python3-os-service-types python3-os-traits python3-os-xenapi python3-osc-lib python3-oslo.cache python3-oslo.concurrency python3-oslo.config python3-oslo.context python3-oslo.db python3-oslo.i18n python3-oslo.log python3-oslo.messaging python3-oslo.middleware python3-oslo.policy python3-oslo.privsep python3-oslo.reports python3-oslo.rootwrap python3-oslo.serialization python3-oslo.service python3-oslo.upgradecheck python3-oslo.utils python3-oslo.versionedobjects python3-osprofiler python3-ovsdbapp python3-paramiko python3-paste python3-pastedeploy python3-pastescript python3-pbr python3-pecan python3-pil python3-pkg-resources python3-ply python3-posix-ipc python3-prettytable python3-psutil python3-pyasn1 python3-pycadf python3-pycparser python3-pygments python3-pyinotify python3-pymysql python3-pyparsing python3-pyperclip python3-pyroute2 python3-repoze.lru python3-requests python3-requestsexceptions python3-rfc3986 python3-roman python3-routes python3-secretstorage python3-setproctitle python3-setuptools python3-simplegeneric python3-simplejson python3-singledispatch python3-six python3-sortedcontainers python3-sqlalchemy python3-sqlalchemy-ext python3-sqlparse python3-statsd python3-stevedore python3-tempita python3-tenacity python3-testresources python3-testscenarios python3-testtools python3-tinyrpc python3-traceback2 python3-tz python3-unicodecsv python3-unittest2 python3-urllib3 python3-vine python3-waitress python3-webencodings python3-webob python3-webtest python3-wrapt python3-yaml sgml-base xml-core 0 upgraded, 184 newly installed, 0 to remove and 95 not upgraded. Need to get 16.3 MB/21.9 MB of archives. After this operation, 140 MB of additional disk space will be used. 2. While running neutron installation on rocky it uses python2.7 packages: add-apt-repository cloud-archive:stein --remove add-apt-repository cloud-archive:rocky root@qtor-ctr101:~# apt install neutron-server Reading package lists... Done Building dependency tree Reading state information... Done The following additional packages will be installed: alembic docutils-common docutils-doc formencode-i18n ieee-data ipset javascript-common libipset3 libjbig0 libjpeg-turbo8 libjpeg8 libjs-jquery libjs-sphinxdoc libjs-underscore liblcms2-2 libpaper-utils libpaper1 libtiff5 libwebp6 libwebpdemux2 libwebpmux3 neutron-common neutron-plugin-ml2 pycadf-common python-alembic python-amqp python-anyjson python-appdirs python-babel python-babel-localedata python-blinker python-bs4 python-cachetools python-ceilometerclient python-certifi python-cffi python-chardet python-cliff python-cmd2 python-concurrent.futures python-contextlib2 python-dateutil python-debtcollector python-decorator python-deprecation python-designateclient python-dnspython python-docutils python-dogpile.cache python-eventlet python-extras python-fasteners python-fixtures python-formencode python-funcsigs python-functools32 python-futurist python-greenlet python-html5lib python-httplib2 python-iso8601 python-jinja2 python-jmespath python-json-pointer python-jsonpatch python-jsonschema python-jwt python-keystoneauth1 python-keystoneclient python-keystonemiddleware python-kombu python-linecache2 python-logutils python-lxml python-mako python-markupsafe python-memcache python-migrate python-mimeparse python-mock python-monotonic python-msgpack python-munch python-netaddr python-netifaces python-neutron python-neutron-lib python-neutronclient python-novaclient python-oauthlib python-olefile python-openid python-openssl python-openstacksdk python-openvswitch python-os-client-config python-os-service-types python-os-xenapi python-osc-lib python-oslo.cache python-oslo.concurrency python-oslo.config python-oslo.context python-oslo.db python-oslo.i18n python-oslo.log python-oslo.messaging python-oslo.middleware python-oslo.policy python-oslo.privsep python-oslo.reports python-oslo.rootwrap python-oslo.serialization python-oslo.service python-oslo.utils python-oslo.versionedobjects python-osprofiler python-ovsdbapp python-paramiko python-paste python-pastedeploy python-pastedeploy-tpl python-pastescript python-pbr python-pecan python-pil python-ply python-posix-ipc python-prettytable python-psutil python-pyasn1 python-pycadf python-pycparser python-pygments python-pyinotify python-pymysql python-pyparsing python-pyperclip python-pyroute2 python-repoze.lru python-requests python-requestsexceptions python-rfc3986 python-roman python-routes python-ryu python-scgi python-simplegeneric python-simplejson python-singledispatch python-sortedcontainers python-sqlalchemy python-sqlalchemy-ext python-sqlparse python-statsd python-stevedore python-tempita python-tenacity python-testresources python-testscenarios python-testtools python-tinyrpc python-traceback2 python-tz python-unicodecsv python-unittest2 python-urllib3 python-vine python-waitress python-weakrefmethod python-webencodings python-webob python-webtest python-wrapt python-yaml python3-alembic python3-dateutil python3-mako python3-markupsafe python3-pkg-resources python3-six python3-sqlalchemy python3-sqlalchemy-ext sgml-base xml-core Suggested packages: apache2 | lighttpd | httpd liblcms2-utils python-editor python-amqp-doc python-blinker-doc python-ceilometerclient-doc python-cliff-doc python-debtcollector-doc fonts-linuxlibertine | ttf-linux-libertine texlive-lang-french texlive-latex-base texlive-latex-recommended python-eventlet-doc python-egenix-mxdatetime python-funcsigs-doc python-futurist-doc python-greenlet-doc python-greenlet-dev python-greenlet-dbg python-genshi python-jinja2-doc python-keystoneauth1-doc python-requests-kerberos python-beanstalkc python-boto python-couchdb python-django python-kombu-doc python-pika python-pymongo python-redis python-lxml-dbg python-lxml-doc python-beaker python-mako-doc memcached python-migrate-doc python-mock-doc ipython python-netaddr-docs python-neutron-lib-doc python-openssl-doc python-openssl-dbg python-openstacksdk-doc python-os-client-config-doc python-os-service-types-doc python-os-xenapi-doc python-osc-lib-doc python-oslo.cache-doc python-oslo.concurrency-doc python-oslo.log-doc python-kafka python-zmq python-oslo.middleware-doc python-oslo.policy-doc python-oslo.privsep-doc python-oslo.reports-doc python-oslo.service-doc python-oslo.versionedobjects-doc python-ovsdbapp-doc python-gssapi httpd-wsgi libapache2-mod-python libapache2-mod-scgi libjs-mochikit python-pastewebkit python-cheetah python-cherrypy python-flup python-pecan-doc python-pil-doc python-pil-dbg python-ply-doc python-psutil-doc ttf-bitstream-vera python-pyinotify-doc python-pymysql-doc python-pyparsing-doc python-pyroute2-doc python-socks python-ryu-doc python-sortedcontainers-doc python-sqlalchemy-doc python-psycopg2 python-pymysql python-fdb python-pymssql python-sqlparse-doc python-tenacity-doc python-testtools-doc python-twisted python-tinyrpc-doc python-ntlm python-waitress-doc python-webob-doc python-webtest-doc python-pyquery python3-editor python3-beaker python3-setuptools python3-psycopg2 python3-mysqldb python3-fdb sgml-base-doc debhelper The following NEW packages will be installed: alembic docutils-common docutils-doc formencode-i18n ieee-data ipset javascript-common libipset3 libjbig0 libjpeg-turbo8 libjpeg8 libjs-jquery libjs-sphinxdoc libjs-underscore liblcms2-2 libpaper-utils libpaper1 libtiff5 libwebp6 libwebpdemux2 libwebpmux3 neutron-common neutron-plugin-ml2 neutron-server pycadf-common python-alembic python-amqp python-anyjson python-appdirs python-babel python-babel-localedata python-blinker python-bs4 python-cachetools python-ceilometerclient python-certifi python-cffi python-chardet python-cliff python-cmd2 python-concurrent.futures python-contextlib2 python-dateutil python-debtcollector python-decorator python-deprecation python-designateclient python-dnspython python-docutils python-dogpile.cache python-eventlet python-extras python-fasteners python-fixtures python-formencode python-funcsigs python-functools32 python-futurist python-greenlet python-html5lib python-httplib2 python-iso8601 python-jinja2 python-jmespath python-json-pointer python-jsonpatch python-jsonschema python-jwt python-keystoneauth1 python-keystoneclient python-keystonemiddleware python-kombu python-linecache2 python-logutils python-lxml python-mako python-markupsafe python-memcache python-migrate python-mimeparse python-mock python-monotonic python-msgpack python-munch python-netaddr python-netifaces python-neutron python-neutron-lib python-neutronclient python-novaclient python-oauthlib python-olefile python-openid python-openssl python-openstacksdk python-openvswitch python-os-client-config python-os-service-types python-os-xenapi python-osc-lib python-oslo.cache python-oslo.concurrency python-oslo.config python-oslo.context python-oslo.db python-oslo.i18n python-oslo.log python-oslo.messaging python-oslo.middleware python-oslo.policy python-oslo.privsep python-oslo.reports python-oslo.rootwrap python-oslo.serialization python-oslo.service python-oslo.utils python-oslo.versionedobjects python-osprofiler python-ovsdbapp python-paramiko python-paste python-pastedeploy python-pastedeploy-tpl python-pastescript python-pbr python-pecan python-pil python-ply python-posix-ipc python-prettytable python-psutil python-pyasn1 python-pycadf python-pycparser python-pygments python-pyinotify python-pymysql python-pyparsing python-pyperclip python-pyroute2 python-repoze.lru python-requests python-requestsexceptions python-rfc3986 python-roman python-routes python-ryu python-scgi python-simplegeneric python-simplejson python-singledispatch python-sortedcontainers python-sqlalchemy python-sqlalchemy-ext python-sqlparse python-statsd python-stevedore python-tempita python-tenacity python-testresources python-testscenarios python-testtools python-tinyrpc python-traceback2 python-tz python-unicodecsv python-unittest2 python-urllib3 python-vine python-waitress python-weakrefmethod python-webencodings python-webob python-webtest python-wrapt python-yaml python3-alembic python3-dateutil python3-mako python3-markupsafe python3-pkg-resources python3-six python3-sqlalchemy python3-sqlalchemy-ext sgml-base xml-core Note: I tried to remove python3 it doesn't help. 3. To switch between openstack repos it require to install software-properties-common package and it also installs python3 itself root@qtor-ctr101:~# apt install software-properties-common Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: accountsservice alembic apport-symptoms bc command-not-found-data docutils-common docutils-doc formencode-i18n gdisk gir1.2-harfbuzz-0.0 icu-devtools ieee-data ipset javascript-common libaccountsservice0 libglib2.0-bin libgraphite2-3 libgraphite2-dev libharfbuzz-gobject0 libharfbuzz-icu0 libharfbuzz0b libicu-le-hb0 libiculx60 libipset3 libjbig0 libjpeg-turbo8 libjpeg8 libjs-jquery libjs-sphinxdoc libjs-underscore liblcms2-2 libpaper-utils libpaper1 libpcre16-3 libpcre3-dev libpcre32-3 libpcrecpp0v5 libselinux1-dev libsepol1-dev libtiff5 libusb-1.0-0 libwebp6 libwebpdemux2 libwebpmux3 linux-headers-4.15.0-55 linux-headers-4.15.0-55-generic linux-image-4.15.0-55-generic linux-modules-4.15.0-55-generic neutron-common neutron-plugin-ml2 pycadf-common python-alembic python-amqp python-anyjson python-appdirs python-babel python-babel-localedata python-blinker python-bs4 python-cachetools python-ceilometerclient python-certifi python-cffi python-chardet python-cliff python-cmd2 python-concurrent.futures python-contextlib2 python-dateutil python-debtcollector python-decorator python-deprecation python-designateclient python-dnspython python-docutils python-dogpile.cache python-eventlet python-extras python-fasteners python-fixtures python-formencode python-funcsigs python-functools32 python-futurist python-greenlet python-html5lib python-httplib2 python-iso8601 python-jinja2 python-jmespath python-json-pointer python-jsonpatch python-jsonschema python-jwt python-keystoneauth1 python-keystoneclient python-keystonemiddleware python-kombu python-linecache2 python-logutils python-lxml python-mako python-markupsafe python-memcache python-migrate python-mimeparse python-mock python-monotonic python-msgpack python-munch python-netaddr python-netifaces python-neutron python-neutron-fwaas python-neutron-lib python-neutronclient python-novaclient python-oauthlib python-olefile python-openid python-openssl python-openstacksdk python-openvswitch python-os-client-config python-os-service-types python-os-xenapi python-osc-lib python-oslo.cache python-oslo.concurrency python-oslo.config python-oslo.context python-oslo.db python-oslo.i18n python-oslo.log python-oslo.messaging python-oslo.middleware python-oslo.policy python-oslo.privsep python-oslo.reports python-oslo.rootwrap python-oslo.serialization python-oslo.service python-oslo.utils python-oslo.versionedobjects python-osprofiler python-ovsdbapp python-paramiko python-paste python-pastedeploy python-pastedeploy-tpl python-pastescript python-pbr python-pecan python-pika python-pika-pool python-pil python-ply python-positional python-posix-ipc python-prettytable python-psutil python-pyasn1 python-pycadf python-pycparser python-pygments python-pyinotify python-pymysql python-pyparsing python-pyperclip python-pyroute2 python-repoze.lru python-requests python-requestsexceptions python-retrying python-rfc3986 python-roman python-routes python-ryu python-scgi python-simplegeneric python-simplejson python-singledispatch python-sqlalchemy python-sqlalchemy-ext python-sqlparse python-statsd python-stevedore python-tempita python-tenacity python-testtools python-tinyrpc python-traceback2 python-tz python-unicodecsv python-unittest2 python-urllib3 python-vine python-waitress python-weakrefmethod python-webencodings python-webob python-webtest python-wrapt python-yaml python3-alembic python3-dateutil python3-mako python3-markupsafe python3-pkg-resources python3-six python3-sqlalchemy run-one sgml-base xml-core Use 'apt autoremove' to remove them. The following additional packages will be installed: lsb-release python3-apt python3-dbus python3-gi python3-software-properties unattended-upgrades Suggested packages: lsb python3-apt-dbg python-apt-doc python-dbus-doc python3-dbus-dbg bsd-mailx default-mta | mail-transport-agent needrestart The following NEW packages will be installed: lsb-release python3-apt python3-dbus python3-gi python3-software-properties software-properties-common unattended-upgrades 0 upgraded, 7 newly installed, 0 to remove and 92 not upgraded. Need to get 0 B/477 kB of archives. After this operation, 2,554 kB of additional disk space will be used.