java running inside docker container cannot see environment variables

Question

I am new with Docker. I have a small Java application that I am trying to run inside Docker. I have created a Dockerfile to build the image.

My application is reading Environment Variables to know which database to connect to.

When running the command

docker run -d -p 80:80 occm -e "MYSQL_USER=user" -e "MYSQL_PASSWORD=password" -e "MYSQL_PORT=3306" -e "MYSQL_HOST=somehost"

and then enumerating all the variables using System.getenv, I dont see any of them. So I have added to the Docker file

ENV MYSQL_HOST=localhost

now when I run the container I see this variable, but I see it with the localhost value and not somehost.

What am I doing wrong?

Shahriar · Accepted Answer · 2018-02-12 16:26:41Z

6

The problem is how you are running your docker image.

$ docker run --help

Usage:  docker run [OPTIONS] IMAGE [COMMAND] [ARG...]

So, you are passing -e "..." -e "..." as command and arguments

You need to use -e as [OPTIONS].

$ docker run -d -p 80:80 -e "MYSQL_USER=user" -e "MYSQL_PASSWORD=password" -e "MYSQL_PORT=3306" -e "MYSQL_HOST=somehost" occm

answered Feb 12, 2018 at 16:13

Shahriar

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