loading docker container from existing project, mongo will not connect to database Ubuntu 18.04 - mongodb

Question

At first I had a problem where the mongod service stopped working altogether. Thereupon I completely uninstalled mongodb and reinstalled it and followed instructions per this thread: https://askubuntu.com/questions/921753/failed-to-start-mongod-service-unit-mongod-service-not-found
This caused the mongod service to finally start.
In order for it to work, I also had to follow instructions from this thread:
mongo - couldn't connect to server 127.0.0.1:27017
So far this configuration has worked only 1 time and that was after I followed the instructions to remove the .lock file in the mongod directory and then repair mongod.
I also tried to remove the sock file like stated here: MongoDB Failing to Start - ***aborting after fassert() failure
Full project reset
Then I tried just disconnecting the project entirely; close nodemon for backend, exit ng serve on frontend, stop and remove mongo docker container... And tried again. Here is my step-by-step process after everything should have been fixed:
Restart mongod service
sudo service mongod restart
Restart frontend (executed from frontend directory)
ng serve frontend
Restart backend (executed from backend directory)
npx nodemon backend
Restart mongo container (executed from deploy directory, mongo is the docker container name, I'm building it from existing provided deploy script)
sudo docker-compose up -d mongo
sudo docker ps -a # check container was created and is running
Debugging information:
sudo service mongod status
Loaded: loaded (/lib/systemd/system/mongod.service; enabled; vendor preset:
Active: active (running) since Thu 2020-01-09 11:21:43 CET; 3min 40s ago
Docs: https://docs.mongodb.org/manual
Main PID: 17242 (mongod)
CGroup: /system.slice/mongod.service
└─17242 /usr/bin/mongod --config /etc/mongod.conf
janv. 09 11:21:43 junior-LIFEBOOK-E752 systemd[1]: Started MongoDB Database Server
sudo mongod2020-01-09T11:25:45.983+0100 I CONTROL [main] Automatically disabling TLS 1.0, to force-enable TLS 1.0 specify --sslDisabledProtocols 'none'
2020-01-09T11:25:45.987+0100 I CONTROL [initandlisten] MongoDB starting : pid=17727 port=27017 dbpath=/data/db 64-bit host=junior-LIFEBOOK-E752
2020-01-09T11:25:45.987+0100 I CONTROL [initandlisten] db version v4.2.2
2020-01-09T11:25:45.987+0100 I CONTROL [initandlisten] git version: a0bbbff6ada159e19298d37946ac8dc4b497eadf
2020-01-09T11:25:45.987+0100 I CONTROL [initandlisten] OpenSSL version: OpenSSL 1.1.1d 10 Sep 2019
2020-01-09T11:25:45.987+0100 I CONTROL [initandlisten] allocator: tcmalloc
2020-01-09T11:25:45.987+0100 I CONTROL [initandlisten] modules: none
2020-01-09T11:25:45.987+0100 I CONTROL [initandlisten] build environment:
2020-01-09T11:25:45.987+0100 I CONTROL [initandlisten] distmod: ubuntu1804
2020-01-09T11:25:45.987+0100 I CONTROL [initandlisten] distarch: x86_64
2020-01-09T11:25:45.987+0100 I CONTROL [initandlisten] target_arch: x86_64
2020-01-09T11:25:45.987+0100 I CONTROL [initandlisten] options: {}
2020-01-09T11:25:45.987+0100 E STORAGE [initandlisten] Failed to set up listener: SocketException: Address already in use
2020-01-09T11:25:45.987+0100 I CONTROL [initandlisten] now exiting
2020-01-09T11:25:45.987+0100 I CONTROL [initandlisten] shutting down with code:48
sudo mongo
connecting to: mongodb://127.0.0.1:27017/?compressors=disabled&gssapiServiceName=mongodb
Implicit session: session { "id" : UUID("8e813fc2-049c-440d-83ce-0b1d8516c4d0") }
MongoDB server version: 4.2.2
Server has startup warnings:
2020-01-09T11:21:43.352+0100 I STORAGE [initandlisten]
2020-01-09T11:21:43.352+0100 I STORAGE [initandlisten] ** WARNING: Using the XFS filesystem is strongly recommended with the WiredTiger storage engine
2020-01-09T11:21:43.352+0100 I STORAGE [initandlisten] ** See http://dochub.mongodb.org/core/prodnotes-filesystem
2020-01-09T11:21:44.848+0100 I CONTROL [initandlisten]
2020-01-09T11:21:44.848+0100 I CONTROL [initandlisten] ** WARNING: Access control is not enabled for the database.
2020-01-09T11:21:44.848+0100 I CONTROL [initandlisten] ** Read and write access to data and configuration is unrestricted.
2020-01-09T11:21:44.848+0100 I CONTROL [initandlisten]
Enable MongoDB's free cloud-based monitoring service, which will then receive and display
metrics about your deployment (disk utilization, CPU, operation statistics, etc).
The monitoring data will be available on a MongoDB website with a unique URL accessible to you
and anyone you share the URL with. MongoDB may use this information to make product
improvements and to suggest MongoDB products and deployment options to you.
To enable free monitoring, run the following command: db.enableFreeMonitoring()
To permanently disable this reminder, run the following command: db.disableFreeMonitoring()
So something weird is happening here, it doesn't find the database from the project and I have no clue why. As far as I can see, it creates a new database including my system details.
How can I fix this please and connect to the project database? I can't move further until I do.

Answer 1

it's been resolved. First I found out I didn't need to have the mongod service running locally because mongo was already included in the docker container. But actually this wasn't a database issue at all. There were a few things going wrong like there was a proxy but the command had been changed to execute the connection, endpoints were on localhost but weren't supposed to be, and the content I was expecting to see had been hidden by a careless push from another developer. Fun times! But we can move on now. Thanks to the people who tried to help!