Mongodb 3.4 on 64bit Ubuntu 16.04 mongodb-27017.sock ERROR - mongodb

Question

There are a few posts related Mongodb 3.2, but when I attempted to install 3.4 the startup does not occur. Instead an unusual error appears in the log file (shown at the very end of the listing).
Is this perhaps because of an older version that was installed?
I did do an apt-get remove and purge.
Can anybody suggest why the error appears?
I followed the steps below, as outlined here,
$ sudo apt-get remove mongodb*
$ sudo apt-get purge mongodb*
$ sudo rm -rf /usr/lib/mongodb
$ sudo rm -rf /usr/log/mongodb
$ sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 0C49F3730359A14518585931BC711F9BA15703C6
$ echo "deb [ arch=amd64,arm64 ] http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.4.list
$ sudo apt-get update
$ sudo apt-get install -y mongodb-org
..
..
E: There were unauthenticated packages and -y was used without --allow-unauthenticated
$ sudo apt-get install mongodb-org # removed -y to get it going
..
..
Setting up mongodb-org (3.4.2) ...
$ sudo chown -R mongodb:mongodb /var/log/mongodb
$ sudo chown -R mongodb:mongodb /var/lib/mongodb # modified ownership in view of what is stated on the mongodb installation note
$ # created the following file
$ cat /etc/systemd/system/mongod.service
[Unit]
Description=MongoDB Database Service 3.4
Wants=network.target
After=network.target
[Service]
User=mongodb
Group=mongodb
ExecStart=/usr/bin/mongod --quiet --config /etc/mongod.conf
StandardOutput=syslog
StandardError=syslog
[Install]
WantedBy=multi-user.target
# startup
$ sudo systemctl daemon-reload
$ sudo service mongod start
# nothing happens, I then viewed the log file and the following error appears:
$ cat /var/log/mongodb/mongod.log
2017-02-08T22:08:26.155+0000 I CONTROL [main] ***** SERVER RESTARTED *****
2017-02-08T22:08:26.159+0000 I CONTROL [initandlisten] MongoDB starting : pid=11384 port=27017 dbpath=/var/lib/mongodb 64-bit host=12g
2017-02-08T22:08:26.159+0000 I CONTROL [initandlisten] db version v3.4.2
2017-02-08T22:08:26.159+0000 I CONTROL [initandlisten] git version: 3f76e40c105fc223b3e5aac3e20dcd026b83b38b
2017-02-08T22:08:26.159+0000 I CONTROL [initandlisten] OpenSSL version: OpenSSL 1.0.2g 1 Mar 2016
2017-02-08T22:08:26.159+0000 I CONTROL [initandlisten] allocator: tcmalloc
2017-02-08T22:08:26.159+0000 I CONTROL [initandlisten] modules: none
2017-02-08T22:08:26.159+0000 I CONTROL [initandlisten] build environment:
2017-02-08T22:08:26.159+0000 I CONTROL [initandlisten] distmod: ubuntu1604
2017-02-08T22:08:26.159+0000 I CONTROL [initandlisten] distarch: x86_64
2017-02-08T22:08:26.159+0000 I CONTROL [initandlisten] target_arch: x86_64
2017-02-08T22:08:26.159+0000 I CONTROL [initandlisten] options: { config: "/etc/mongod.conf", net: { bindIp: "127.0.0.1", port: 27017 }, storage: { dbPath: "/var/lib/mongodb", journal: { enabled: true } }, systemLog: { destination: "file", logAppend: true, path: "/var/log/mongodb/mongod.log", quiet: true } }
2017-02-08T22:08:26.178+0000 E NETWORK [initandlisten] Failed to unlink socket file /tmp/mongodb-27017.sock Operation not permitted

Answer 1

Failed to unlink socket file /tmp/mongodb-27017.sock Operation not permitted
That means the mongod process was started by root user.So you can just remove the sock file or run this command to fix this issue :
sudo chown `whoami` /tmp/mongodb-*.sock
Make sure that the port you assign needs to be accessible and not blocked by your firewall and then just restart the mongod process.
The waiting for connections message in the console output indicates
that the mongod.exe process is running successfully.
You can check out Install MongoDB Community Edition on Ubuntu.
Hope this helps.

Answer 2

#mcgraddy, thanks, that was helpful indeed. Creating the directory and copying the service file was the answer.
$ sudo cp /etc/systemd/system/mongod.service /etc/systemd/system/mongodb.service
$ sudo mkdir -p /data/db
$ sudo chown -R $USER:$USER /data
I had to change ownership for /data.
Starting the service and viewing status shows everything is running as expected:
$ sudo service mongod start
$ sudo systemctl status mongodb
● mongodb.service - MongoDB Database Service
Loaded: loaded (/etc/systemd/system/mongodb.service; enabled; vendor preset:
Active: active (running) since Thu 2017-02-09 13:26:07 GMT; 9min ago
Main PID: 1184 (mongod)
CGroup: /system.slice/mongodb.service
└─1184 /usr/bin/mongod --quiet --config /etc/mongod.conf
Feb 09 13:26:07 systemd[1]: Started MongoDB Database Service.