bugfix: Adds tip to maven-integration section to use containers for e… (

#497)

* bugfix: Adds tip to maven-integration section to use containers for exercise, and adds example Dockerfiles and docker compose files to examples directory

* chore: linting

* chore: fixed reversed link

docs/6-release-management/6.2.2-maven-integration.md

@@ -37,6 +37,10 @@ Here are two ways of doing this.
 
 This section is designed to give you an introduction into how Maven interacts with Nexus and how to use Maven in GitHub Actions.
 
+## Tips
+
+Use containerization for the following exercise, see [examples](https://github.com/liatrio/devops-bootcamp/tree/master/examples/ch6/Dev-Containers).
+
 1. Fork the following repos:
    - [spring-petclinic](https://github.com/liatrio/spring-petclinic)
    - [joda-time](https://github.com/JodaOrg/joda-time)

examples/ch6/Dev-Containers/Dockerfile.joda

@@ -0,0 +1,16 @@
+# FROM ubuntu:22.04
+FROM --platform=linux/amd64 ubuntu:22.04
+ARG DEBIAN_FRONTEND=noninteractive
+RUN apt-get update && apt-get upgrade -y  && \
+apt-get install bash -y && \
+apt-get install sudo -y && \
+apt-get install git -y && \
+apt-get install vim -y && \
+apt-get install openjdk-8-jdk -y && \
+apt-get install maven -y && \
+useradd -ms /bin/bash JODA && usermod -aG sudo JODA && \
+echo '%sudo ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers
+WORKDIR /home/joda-time
+COPY /joda-time /home/joda-time/
+RUN chown -R JODA:JODA /home/joda-time
+USER JODA

examples/ch6/Dev-Containers/Dockerfile.nexus

@@ -0,0 +1,18 @@
+FROM ubuntu:20.04
+# Create the "nexus" user and group
+RUN addgroup --system nexus && adduser --system --ingroup nexus nexus
+# Create the /opt/nexus directory with the correct permissions
+RUN mkdir -p /opt/nexus
+# Install required packages and download Nexus
+RUN apt-get update && \
+    apt-get upgrade -y && \
+    apt-get install wget openjdk-8-jdk -y && \
+    wget https://download.sonatype.com/nexus/3/nexus-3.64.0-04-unix.tar.gz -P /opt/nexus/
+# Move and extract Nexus files
+RUN tar -xvf /opt/nexus/nexus-3.64.0-04-unix.tar.gz -C /opt/nexus/ && \
+    rm -f /opt/nexus/nexus-3.64.0-04-unix.tar.gz
+# Set ownership for the Nexus installation directory
+RUN chown -R nexus:nexus /opt/nexus
+# EXPOSE 8081
+USER nexus
+ENTRYPOINT ["/opt/nexus/nexus-3.64.0-04/bin/nexus", "run"]

examples/ch6/Dev-Containers/Dockerfile.springpetclinic

@@ -0,0 +1,16 @@
+# FROM ubuntu:22.04
+FROM --platform=linux/amd64 ubuntu:22.04
+ARG DEBIAN_FRONTEND=noninteractive
+RUN apt-get update && apt-get upgrade -y  && \
+apt-get install bash -y && \
+apt-get install sudo -y && \
+apt-get install git -y && \
+apt-get install vim -y && \
+apt-get install openjdk-17-jdk -y && \
+apt-get install maven -y && \
+useradd -ms /bin/bash SPC && usermod -aG sudo SPC && \
+echo '%sudo ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers
+WORKDIR /home/spring-petclinic
+COPY /spring-petclinic /home/spring-petclinic/
+RUN chown -R SPC:SPC /home/spring-petclinic
+USER SPC

examples/ch6/Dev-Containers/docker-compose.yml

@@ -0,0 +1,21 @@
+version: "3.8"
+services:
+  jodatime:
+    container_name: jodatime
+    build:
+      dockerfile: Dockerfile.joda
+  springpetclinic:
+    container_name: springpetclinic
+    build:
+      dockerfile: Dockerfile.springpetclinic
+  nexusserver:
+    container_name: nexusserver
+    build: 
+      dockerfile: Dockerfile.nexus
+    ports:
+      - "8081:8081"
+    volumes:
+      - nexus:/opt/nexus
+      - nexus:/nexus-data
+volumes:
+  nexus: