feat: solely handle single terminating signal for now

Dockerfile

@@ -0,0 +1,64 @@
+FROM rust:1.70-alpine3.18 AS builder
+
+ARG DI_VER=1.2.5
+
+WORKDIR /app
+
+COPY . ./
+
+RUN apk add --no-cache build-base unzip curl && \
+    curl -Lo - "https://github.com/Yelp/dumb-init/archive/refs/tags/v${DI_VER}.tar.gz" | tar -xzf - && \
+    cd "dumb-init-${DI_VER}" && \
+    make SHELL=/bin/sh && \
+    mv dumb-init ..
+
+RUN cargo build && \
+    [ "$(readelf -d target/debug/alex | grep NEEDED | wc -l)" = 0 ]
+
+
+# We use ${:-} instead of a default value because the argument is always passed
+# to the build, it'll just be blank most likely
+FROM eclipse-temurin:17-jre-alpine
+
+# Build arguments
+ARG MC_VERSION=1.19.4
+ARG PAPERMC_VERSION=545
+
+RUN addgroup -Sg 1000 paper && \
+    adduser -SHG paper -u 1000 paper
+
+# Create worlds and config directory
+WORKDIR /app
+RUN mkdir -p worlds config/cache backups
+
+# Download server file
+ADD "https://papermc.io/api/v2/projects/paper/versions/$MC_VERSION/builds/$PAPERMC_VERSION/downloads/paper-$MC_VERSION-$PAPERMC_VERSION.jar" server.jar
+
+# Make sure the server user can access all necessary folders
+RUN chown -R paper:paper /app
+
+# Store the cache in an anonymous volume, which means it won't get stored in the other volumes
+VOLUME /app/config/cache
+VOLUME /app/backups
+
+COPY --from=builder /app/dumb-init /bin/dumb-init
+COPY --from=builder /app/target/debug/alex /bin/alex
+
+RUN chmod +x /bin/alex
+
+# Default value to keep users from eating up all ram accidentally
+ENV ALEX_XMS=1024 \
+    ALEX_XMX=2048 \
+    ALEX_JAR=/app/server.jar \
+    ALEX_CONFIG_DIR=/app/config \
+    ALEX_WORLD_DIR=/app/worlds \
+    ALEX_BACKUPS_DIR=/app/backups \
+    ALEX_SERVER_VERSION="${MC_VERSION}-${PAPERMC_VERSION}"
+
+# Document exposed ports
+EXPOSE 25565
+
+# Switch to non-root user
+USER paper:paper
+
+ENTRYPOINT ["/bin/alex", "paper"]