[docker] Update root Dockerfile and run-in-docker

This update allows the root Dockerfile to be used as a development
container and updates run-in-docker.sh to use the same entrypoint script
while maintaining backward compatibility for anyone who has scripted
mappings to /gen and /root/.m2/repository.

Dockerfile

@@ -1,16 +1,22 @@
 FROM jimschubert/8-jdk-alpine-mvn:1.0
 
+ENV GEN_DIR /opt/swagger-codegen
+
+RUN set -x && \
+    apk add --no-cache bash
+
 RUN mkdir /opt
 
-ADD . /opt/swagger-codegen
+ADD . ${GEN_DIR}
+
+VOLUME  ${MAVEN_HOME}/.m2/repository
+
+WORKDIR ${GEN_DIR}
 
-WORKDIR /opt/swagger-codegen
+RUN mvn -am -pl "modules/swagger-codegen-cli" package
 
-RUN mvn -am -pl "modules/swagger-codegen-cli" package && \
-    mv /opt/swagger-codegen/modules/swagger-codegen-cli/target/swagger-codegen-cli.jar /opt/swagger-codegen/swagger-codegen-cli.jar && \
-    mvn clean && \
-    rm -rf ${MAVEN_HOME}/.m2/repository
+COPY docker-entrypoint.sh /usr/local/bin/
 
-ENTRYPOINT ["java", "-jar", "/opt/swagger-codegen/swagger-codegen-cli.jar"]
+ENTRYPOINT ["docker-entrypoint.sh"]
 
-CMD ["help"]
+CMD ["build"]

docker-entrypoint.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+# GEN_DIR allows to share the entrypoint between Dockerfile and run-in-docker.sh (backward compatible)
+GEN_DIR=${GEN_DIR:-/opt/swagger-codegen}
+JAVA_OPTS=${JAVA_OPTS:-"-Xmx1024M -DloggerPath=conf/log4j.properties"}
+
+codegen="${GEN_DIR}/modules/swagger-codegen-cli/target/swagger-codegen-cli.jar"
+
+case "$1" in
+    generate|help|langs|meta|config-help)
+        # If ${GEN_DIR} has been mapped elsewhere from default, and that location has not been built
+        if [[ ! -f "${codegen}" ]]; then
+            (cd ${GEN_DIR} && exec mvn -am -pl "modules/swagger-codegen-cli" package)
+        fi
+        command=$1
+        shift
+        exec java ${JAVA_OPTS} -jar ${codegen} ${command} "$@"
+        ;;
+    *)  # Any other commands, e.g. docker run imagename ls -la or docker run -it imagename /bin/bash
+        exec "$@"
+        ;;
+esac

run-in-docker.sh

@@ -1,34 +1,16 @@
 #!/bin/bash
-set -e
-cd "$(dirname $BASH_SOURCE)"
+set -exo pipefail
 
-maven_cache_repo="$HOME/.m2/repository"
-myname="$(basename $BASH_SOURCE)"
+cd "$(dirname ${BASH_SOURCE})"
 
-if [ "$1" = "mvn" ]; then
-        cmd="$1"
-        shift
-        args="$@"
-else
-        jar="modules/swagger-codegen-cli/target/swagger-codegen-cli.jar"
-        
-        # Check if project is built
-        if [ ! -f "$jar" ]; then
-                echo "ERROR File not found: $jar"
-                echo "ERROR Did you forget to './$myname mvn package'?"
-                exit 1
-        fi
-        
-        cmd="java -jar /gen/$jar"
-        args="$@"
-fi
+maven_cache_repo="${HOME}/.m2/repository"
 
-mkdir -p "$maven_cache_repo"
+mkdir -p "${maven_cache_repo}"
 
-set -x
-
-docker run -it \
+docker run --rm -it \
         -w /gen \
+        -e GEN_DIR=/gen \
         -v "${PWD}:/gen" \
         -v "${maven_cache_repo}:/root/.m2/repository" \
-        maven:3-jdk-7 $cmd $args
+        --entrypoint /gen/docker-entrypoint.sh \
+        maven:3-jdk-7 "$@"