Grails apps in docker, installation of spring-security plugins? - docker

Question

A newbie question regarding both Grails app running in Docker, and spring-security-ldap 2.0.1 plugin.
Currently I am running a local Grails apps (not in Docker), installation of spring-security-ldap 2.0.1 is pretty simple with mainly a added line in BuildConfig.groovy:
plugins {
compile ":spring-security-ldap:2.0.1"
}
After implemented the necessary user details and mapping classes, the first time running the Grails app, the installation of spring-security-ldap is automatically carried out and install a bunch of stuff under the
//src/target/work/plugins/spring-security-ldap-2.0.1/ folder, these are the things that drive the Ldap login support I supposed.
Now, if I were to move my Grails App into a docker container, what is the proper way to get this plugin installation done? Where to specify the resolution and installation of the plugin?
[Update 20180425]
NVM, I just tried it with my changed codes (specifying the LDAP plugins in BuildConfig.groovy), rebuilt the Docker images, and executed it and I can now see the auth login page. That means the plugin had been successfully resolved from external repo and built into the Docker image!
The problem now is, I am not able to log in with the test users:
org.springframework.security.authentication.InternalAuthenticationServiceException: localhost:389; nested exception is javax.naming.CommunicationException: localhost:389 [Root exception is java.net.ConnectException: Connection refused (Connection refused)]
It has to be about the opening the Docker in/out ports for my local OpenLdap. I will read a bit on Docker documentation for this.

Answer 1

First of all, create a war file using grails war. It will automatically add all the dependencies in the war file including spring-security-ldap. You don't have to worry about anything regarding dependency injection.
Afterward, you can follow these steps to create and run a docker image:
A) Creating Dockerfile
Create a file named Dockerfile in your project directory with the following content:
FROM tomcat:7.0.86-jre7
WORKDIR /usr/local/tomcat/bin
COPY <path/to/your-war-file> /usr/local/tomcat/webapp/<application-name>.war
CMD ["catalina.sh", "run"]
B) Creating an Image
Simply execute docker build -t <image name>:<image version> . This will create a docker image in your local docker engine.
C) Running the Container
Finally, start your application by executing docker run -p <port you wanna bind>:8080 <image name>:<image version>
If everything goes right, you can now access your application on the port you bound in docker run .. command.
Update
To answer your updated question, when you access localhost inside a container, it doesn't resolve to the localhost of the docker host machine. It resolves to the container itself. So, if you have something running on the host machine (OpenLDAP on port 389 in this case), you'll have to access this by using the IP of the host machine.
A better solution, in this case, is to run OpenLDAP in docker container also. That way, you can access OpenLDAP with its hostname and you won't have to change the IP if it changes.