ci: add PPC docker build pipeline (#2)

This creates an image with hardcoded version of the contained mage for testing.

Afterwards a process needs to be defined to either pass the version onto the container whenever a release triggers it, or actually build from source.

Dockerfile

@@ -0,0 +1,50 @@
+# build xmage
+# currently fails due to mismatching versions. how did this build ever work?
+
+# FROM maven:3-jdk-8 AS builder
+
+# COPY . .
+# RUN ls -la  \
+#  && mvn clean install -DskipTests \ 
+#  && cd ./Mage.Client \
+#  && ls -la \
+#  && mvn package assembly:single \
+#  && cd ./Mage.Server \
+#  && ls -la \
+#  && mvn package assembly:single \
+#  && ls -la target \
+#  && unzip target/mage-server.zip -d xmage-server
+
+# instead of building, pull from current release
+FROM curlimages/curl AS builder
+
+WORKDIR /tmp
+
+RUN curl https://github.com/magefree/mage/releases/download/xmage_1.4.53V1/mage-full_1.4.53-dev_2024-08-16_15-45.zip -L -o xmage.zip \
+&& ls -la \
+&& unzip -q xmage.zip -d xmage
+
+FROM openjdk:8-jre
+
+ENV XMAGE_DOCKER_SERVER_ADDRESS="0.0.0.0" \
+    XMAGE_DOCKER_PORT="17171" \
+    XMAGE_DOCKER_SEONDARY_BIND_PORT="17179" \
+    XMAGE_DOCKER_MAX_SECONDS_IDLE="600" \
+    XMAGE_DOCKER_AUTHENTICATION_ACTIVATED="false" \
+    XMAGE_DOCKER_SERVER_NAME="mage-server"
+
+EXPOSE 17171 17179
+WORKDIR /xmage
+
+# from being built
+# COPY --from=builder /Utils/xmage-server .
+
+# from release
+COPY --from=builder tmp/xmage/xmage/mage-server /xmage/
+COPY dockerContainerStart.sh /xmage/
+
+RUN chmod +x \
+    /xmage/startServer.sh \
+    /xmage/dockerContainerStart.sh
+
+CMD [ "./dockerContainerStart.sh" ]