dockerfile – Make Me Engineer

How to create a Mongo Docker Image with default collections and data?

June 14, 2023 by Tarik

The problem was that information could not be saved on /db/data, so I’ve created a solution creating my own data directory. # Parent Dockerfile https://github.com/docker-library/mongo/blob/982328582c74dd2f0a9c8c77b84006f291f974c3/3.0/Dockerfile FROM mongo:latest # Modify child mongo to use /data/db2 as dbpath (because /data/db wont persist the build) RUN mkdir -p /data/db2 \ && echo “dbpath = /data/db2” > /etc/mongodb.conf \ … Read more

Docker container doesn’t expose ports when –net=host is mentioned in the docker run command

June 11, 2023 by Tarik

I was confused by this answer. Apparently my docker image should be reachable on port 8080. But it wasn’t. Then I read https://docs.docker.com/network/host/ To quote The host networking driver only works on Linux hosts, and is not supported on Docker for Mac, Docker for Windows, or Docker EE for Windows Server. That’s rather annoying as … Read more

Single file volume mounted as directory in Docker

June 7, 2023 by Tarik

Maybe that’s clear in the answers above… but it took me some time to figure it out in my case. The underlying reason causing the file being shared with -v to appear as a directory instead of a file is that Docker could not find the file on the host. So Docker creates a new … Read more

Docker: Using –password via the CLI is insecure. Use –password-stdin

June 7, 2023 by Tarik

How to cache the RUN npm install instruction when docker build a Dockerfile

June 6, 2023 by Tarik

Ok so I found this great article about efficiency when writing a docker file. This is an example of a bad docker file adding the application code before running the RUN npm install instruction: FROM ubuntu RUN echo “deb http://archive.ubuntu.com/ubuntu precise main universe” > /etc/apt/sources.list RUN apt-get update RUN apt-get -y install python-software-properties git build-essential … Read more

Dockerfile build – possible to ignore error?

June 6, 2023 by Tarik

Sure. Docker is just responding to the error codes returned by the RUN shell scripts in the Dockerfile. If your Dockerfile has something like: RUN make You could replace that with: RUN make; exit 0 This will always return a 0 (success) exit code. The disadvantage here is that your image will appear to build … Read more

How to name Dockerfiles

June 5, 2023 by Tarik

[Please read the full answer]Don’t change the name of the dockerfile if you want to use the autobuilder at hub.docker.com. Don’t use an extension for docker files, leave it null. File name should just be: (no extension at all) Dockerfile However, now you can name dockerfiles like, test1.Dockerfile $ docker build -f dockerfiles/test1.Dockerfile -t test1_app … Read more

How to convert a Spring-Boot web service into a Docker image?

June 4, 2023 by Tarik

When you run a Docker container, all the ports, which any application happen to listen on within it, are not published by default. In order to publish a port, you need to specify it while running the container using your image. For all the details on how to do it, you can check the “EXPOSE” … Read more

Multiple commands on docker ENTRYPOINT

May 23, 2023 by Tarik

In case you want to run many commands at entrypoint, the best idea is to create a bash file. For example commands.sh like this #!/bin/bash mkdir /root/.ssh echo “Something” cd tmp ls … And then, in your DockerFile, set entrypoint to commands.sh file (that execute and run all your commands inside) COPY commands.sh /scripts/commands.sh RUN … Read more

Use docker run command to pass arguments to CMD in Dockerfile

May 22, 2023 by Tarik

Make sure your Dockerfile declares an environment variable with ENV: ENV environment default_env_value ENV cluster default_cluster_value The ENV <key> <value> form can be replaced inline. Then you can pass an environment variable with docker run. Note that each variable requires a specific -e flag to run. docker run -p 9000:9000 -e environment=dev -e cluster=0 -d … Read more