I am currently creating a Java program that uses a MongoDB database and I am storing the connection information in a properties file.
But my project is opensource on GitHub and I cannot store the connection information in the properties file.
And so I wanted to ask you if it is possible to give the login information from docker run.
example : docker run registry/image -args db.password=psw db.username=user
I have seen solutions in stackoverflow but all solutions use Spring features, but my project does not use Spring framework.
We have multiple solutions for this:
Create a file with the properties syntax:
//secret-file.txt
db.password=psw
db.username=user
With this file create a docker secret in your docker :
$ docker secret create test-secret secret-file.txt
And use this with the java library docker-secrets in your java program :
Map<String, String> secrets = DockerSecrets.loadFromFile("test-secret");
System.out.println(secrets.get("db.password")) // readonly
For more example, look here.
Set the environment variables in the docker with -e argument :
$ docker run -e DB_PASSWORD=pwd -e DB_USERNAME=user registry/image:tag
And use these variables with System::getenv in your java program :
System.out.println(System.getenv("DB_PASSWORD"))
This solution depends on your base image that was used to create your Docker container.
Give VM Arguments to the docker run command :
$ docker run -e JAVA_OPTS="-Ddb.password=pwd -Ddb.username=user" registry/image:tag
And use these variables with System::getProperty in your java program :
System.out.println(System.getProperty("db.password"))
Give arguments to docker run command :
It is important to give the arguments after declaring the image.
$ docker run registry/image:tag pwd user
And use these arguments with main method in your java program :
public static void main(String[] args) {
System.out.println("The password: " + args[0]);
System.out.println("The username: " + args[1]);
}
For better handling of arguments, you can use the Apache's commons-cli java library or use a another library.
if you are hosting this application on AWS an option is using Secrets Manager which has an integration start project for Spring - How to integrate AWS Secret Manager with Spring Boot Application