Conteneuriser une application JAVA (pour l'instant, une doc publique permettant de rationnaliser les devs externes)

create.sh

docker build -t sipf/CODENAME:VERSION .

docker-entrypoint.sh

#!/bin/bash
set -e

# usage: file_env VAR [DEFAULT]
#    ie: file_env 'XYZ_DB_PASSWORD' 'example'
# (will allow for "$XYZ_DB_PASSWORD_FILE" to fill in the value of
#  "$XYZ_DB_PASSWORD" from a file, especially for Docker's secrets feature)
file_env() {
	local var="$1"
	local fileVar="${var}_FILE"
	local def="${2:-}"
	if [[ "${!var:-}" ]] && [[ "${!fileVar:-}" ]]; then
		echo >&2 "error: both $var and $fileVar are set (but are exclusive)"
		exit 1
	fi
	local val="$def"
	if [[ "${!var:-}" ]]; then
		val="${!var}"
	elif [[ "${!fileVar:-}" ]]; then
		val="$(< "${!fileVar}")"
	fi
    export "$var"="$val"
	unset "$fileVar"
}

file_env SPRING_DATASOURCE_URL
file_env SPRING_DATASOURCE_USERNAME
file_env SPRING_DATASOURCE_PASSWORD

file_env SECURITY_OAUTH2_CLIENT_CLIENTID
file_env SECURITY_OAUTH2_CLIENT_CLIENTSECRET

exec java $JAVA_OPTS \
    -Dfile.encoding=UTF-8 \
    -Dspring.main.banner-mode=OFF \
    -XX:+UnlockExperimentalVMOptions \
    -XX:+UseCGroupMemoryLimitForHeap \
    -XshowSettings:vm \
    -Djava.security.egd=file:/dev/./urandom \
    -jar /opt/app/app.jar

Dockerfile

FROM govpf/maven:3.6-jdk-8 AS build
WORKDIR /opt/app/
COPY . .
RUN mvn -B package -DskipTests

FROM govpf/openjdk:8-jre

# Build-time metadata as defined at http://label-schema.org
ARG BUILD_DATE
ARG VCS_REF
ARG VERSION
LABEL org.label-schema.build-date=$BUILD_DATE \
      org.label-schema.name="CODENAME" \
      org.label-schema.description="DESCRIPTION" \
      org.label-schema.url="https://URL" \
      org.label-schema.vcs-ref=$VCS_REF \
      org.label-schema.vcs-url="https://gitlab.gov.pf/CODENAME" \
      org.label-schema.vendor="SIPF" \
      org.label-schema.version=$VERSION \
      org.label-schema.schema-version="1.0"

# JRE fails to load fonts if there are no standard fonts in the image; DejaVu is a good choice,
# see https://github.com/docker-library/openjdk/issues/73#issuecomment-207816707
RUN apk add --update ttf-dejavu && rm -rf /var/cache/apk/*

WORKDIR /opt/app
COPY --from=build /opt/app/target/*.jar app.jar
COPY docker-entrypoint.sh /opt/app/docker-entrypoint.sh

ENV JAVA_OPTS="-XX:MinRAMPercentage=50.0 -XX:MaxRAMPercentage=80.0"

ENTRYPOINT ["/opt/app/docker-entrypoint.sh"]