Node init fails on debian9 and ubuntu18

root@deb91-qe:/tmp# /opt/couchbase/bin/couchbase-cli node-init -c localhost -u Administrator -p password;

/opt/couchbase/bin/couchbase-cli: 4: cd: can't cd to /opt/couchbase/bin/../lib/python

Installing Python 3 - one moment...

sh: 0: Can't open /opt/couchbase/bin/../lib/python/cbpy-installer.sh

/opt/couchbase/bin/couchbase-cli: 25: exec: /root/Library/Python/couchbase-py/7.0.0-py4/bin/python3: not found

root@deb91-qe:/tmp# /opt/couchbase/bin/couchbase-cli node-init -c localhost -u Administrator -p password;

ERROR: Unable to connect to host at http://localhost:8091: HTTPConnectionPool(host='localhost', port=8091): Max retries exceeded with url: /nodeInit (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7fa5621cd828>: Failed to establish a new connection: [Errno 111] Connection refused'

dpkg --purge couchbase-server; kill -9 `ps -ef |egrep couchbase|cut -f3 -d' '`; 

rm /var/lib/dpkg/info/couchbase-server.*; 

rm -rf /opt/couchbase/;

apt-get update;

cd /tmp;

rm -rf *upgrade-from;

dpkg -i couchbase-server-enterprise_7.0.0-4756-debian9_amd64.deb

sed -i 's/export PATH/export PATH\nexport CBFT_ENV_OPTIONS=bleveMaxResultWindow=10000000/' /opt/couchbase/bin/couchbase-server; grep bleveMaxResultWindow=10000000 /opt/couchbase/bin/couchbase-server > /dev/null && echo 1 || echo 0;

/opt/couchbase/bin/couchbase-cli node-init -c localhost -u Administrator -p password;