Mongodb on debian docker image - unable to stand - mongodb

Question

Good evening.
I'm noobie in docker and try to learn it a little bit. Currently writing simple java application integrated with mongodb, but I stuck on dockerfile. Basically the problem is with mongodb start. Here is my docker file:
FROM debian:buster-slim
# Install necessary libs
RUN apt-get update && apt-get install -y apt-utils wget gnupg gnupg2 curl
# Install mongodb
RUN wget -qO - https://www.mongodb.org/static/pgp/server-4.2.asc | apt-key add -
RUN echo "deb [ arch=amd64 ] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/4.2 multiverse" | tee /etc/apt/sources.list.d/mongodb-org-4.2.list
RUN apt-get update
RUN apt-get install -y mongodb-org
RUN systemctl enable mongod.service
RUN service mongod start
# Install jre 11
RUN apt-get install -y openjdk-11-jre
Here is the terminal output (only last step):
Setting up mongodb-org-shell (4.2.1) ...
Setting up mongodb-org-tools (4.2.1) ...
Setting up mongodb-org-mongos (4.2.1) ...
Setting up mongodb-org (4.2.1) ...
Removing intermediate container 7491080bfe9f
---> bbcf5b2ccb13
Step 7/11 : RUN service mongod start
---> Running in 46a66989ade2
mongod: unrecognized service
The command '/bin/sh -c service mongod start' returned a non-zero code: 1
Funny think is that I followed an official mongodb installation guide:
Mongodb installation on debian
During installation on 'real' debian/ubuntu machine it works.
It also doesn't work when tried to build docker image from official mongodb image from docker hub, I mean FROM mongo:4.2-bionic
After login to container and try to run mongo it returns:
root#8cc1d270a262:~# mongo
MongoDB shell version v4.2.0
connecting to: mongodb://127.0.0.1:27017/?compressors=disabled&gssapiServiceName=mongodb
2019-10-23T20:39:44.728+0000 E QUERY [js] Error: couldn't connect to server 127.0.0.1:27017, connection attempt failed: SocketException: Error connecting to 127.0.0.1:27017 :: caused by :: Connection refused :
connect#src/mongo/shell/mongo.js:341:17
#(connect):2:6
2019-10-23T20:39:44.729+0000 F - [main] exception: connect failed
2019-10-23T20:39:44.729+0000 E - [main] exiting with code 1
I expected that, cause mongo is unable to stand... Somehow.
Any ideas?

Answer 1

So, it seems when trying to follow the instructions to install MongoDB on Debian the SysVInit files are not created and error message mongod: unrecognized service. So a basic question: Does a docker container really need daemon control with either SysVInit or systemd? I don't think it really needs it, and my reason is because the container itself has a single purpose - to host the database. The container should always have the database engine running. With this philosophy in mind, I altered the Dockerfile to include an ENTRYPOINT that starts the mongod instead of relying on any daemon management system.
In order for the MongoDB database to be available outside the container I adjusted the mongod.conf file to bind to all network adapters by using bindIp: 0.0.0.0 instead of bindIp: 127.0.0.1. I also expose port 27017 in the Dockerfile. This means if you have MongoDB installed and running on the host computer using the default port 27107 that process will need to be halted to yield the port to the Docker container.
I was getting some errors in the container around the debconf stuff so I set it non-interactive as well. The installation of java was giving me fits, so I commented it out. If you need java on this container this will still need to be worked out.
Dockerfile:
FROM debian:buster-slim
RUN echo 'debconf debconf/frontend select Noninteractive' | debconf-set-selections
# Install necessary libs
RUN apt-get update && apt-get install -y apt-utils wget gnupg gnupg2 curl
# Install mongodb
RUN wget -qO - https://www.mongodb.org/static/pgp/server-4.2.asc | apt-key add -
RUN echo "deb [ arch=amd64 ] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/4.2 multiverse" | tee /etc/apt/sources.list.d/mongodb-org-4.2.list
RUN apt-get update
RUN apt-get install -y mongodb-org
# BIND TO ALL ADAPTERS IN CONTAINER
RUN sed -i "s,\\(^[[:blank:]]*bindIp:\\) .*,\\1 0.0.0.0," /etc/mongod.conf
# Install jre 11
# RUN "apt-get install -y openjdk-11-jre"
EXPOSE 27017
ENTRYPOINT ["/usr/bin/mongod", "-f", "/etc/mongod.conf"]
Build:
To build the Docker image issue the following command...
docker build --tag mongodb .
(notice the period in the command - it is required).
Run:
To create a docker container, use the run command.
docker run --publish 27017:27017 --name mongodb -d mongodb
Notice the --publish to map host port 27017 to container port 27017. Notice the --name to name the container for easier reference if we need to get a bash shell inside the container. Run -d for detached mode so it runs in the background, and finally refer to the image named mongodb.
Connect:
Assuming MongoDB is installed on the host too the mongo shell binary will be available. Issue a mongo shell command...
mongo
No other parameters are needed. The installation of MongoDB in the container does not have authorization enabled and so does not ask for a username or password. The default port of 27107 is used by the container and mapped by the docker engine. Localhost is used by default.
Get BASH shell of container:
If you want to get a BASH shell inside of the container issue the following command...
docker exec -it mongodb bash

Answer 2

Try to run mongodb docker container and connect to it using mongo client before building custom images:
docker run --name some-mongo -e MONGO_INITDB_ROOT_USERNAME=mongoadmin -e MONGO_INITDB_ROOT_PASSWORD=secret -d mongo
docker exec -it some-mongo bash
mongo -u mongoadmin -p secret --authenticationDatabase admin