Multi stage Docker file for image creation based on Alpine Linux, Tomcat native, OpenJDK JRE, and FFMPEG 4.x. WAR file has to be decompressed outside.

Dockerfile_1

# OpenJDK 12 alpine jdk/jre uses alpine 3.10.
# Visit https://github.com/AdoptOpenJDK/openjdk-docker/blob/master/12/jre/alpine/Dockerfile.hotspot.releases.full

######################################################################################################
FROM alpine:3.10 AS STAGING-TOMCAT

LABEL maintainer="fabri1983dockerid"

############# INSTALL NATIVE TOMCAT #############
ENV CATALINA_HOME=/opt/tomcat \
    TOMCAT_MAJOR="8" \
    TOMCAT_VERSION="8.5.43" \
    # default JVM installation when downloaded as a package
    TEMP_JAVA_HOME=/usr/lib/jvm/default-jvm
    
# Download OpenJDK 11 (12 is not available), Tomcat, and then Build tc-native
RUN apk add --no-cache --virtual .my-build-deps apr-dev openssl-dev openjdk11-jdk make g++ && \
    cd /tmp && \
    wget -O apache-tomcat.tar.gz http://archive.apache.org/dist/tomcat/tomcat-${TOMCAT_MAJOR}/v${TOMCAT_VERSION}/bin/apache-tomcat-${TOMCAT_VERSION}.tar.gz && \
    tar -C /opt -xf apache-tomcat.tar.gz && \
    ln -s /opt/apache-tomcat-$TOMCAT_VERSION $CATALINA_HOME && \
    cd $CATALINA_HOME/bin && \
    tar -xf tomcat-native.tar.gz && \
    rm -f tomcat-native.tar.gz && \
    cd tomcat-native-*-src/native && \
    ./configure --with-java-home=$TEMP_JAVA_HOME --prefix=$CATALINA_HOME && \
    make && \
    make install && \
    make clean && \
    rm -rf /tmp/* && \
    # Remove added packages
    apk del --purge .my-build-deps && \
    rm -rf /var/cache/apk/*

#################################################

################ MINIMAL TOMCAT #################
# Minimal Tomcat: remove all default webapps

RUN rm -rf \
  ${CATALINA_HOME}/webapps/ROOT \
  ${CATALINA_HOME}/webapps/docs \
  ${CATALINA_HOME}/webapps/examples \
  ${CATALINA_HOME}/webapps/host-manager \
  ${CATALINA_HOME}/webapps/manager
#################################################


######################################################################################################
FROM alpine:3.10 AS STAGING-WAR
ARG DEPENDENCIES=docker-workdir

LABEL maintainer="fabri1983dockerid"

################# STAGING WAR ###################
# Create target folder
RUN mkdir -p /staging/app/

# Stage dependencies and classes
COPY ${DEPENDENCIES}/META-INF             /staging/app/META-INF
COPY ${DEPENDENCIES}/WEB-INF              /staging/app/WEB-INF
COPY ${DEPENDENCIES}/general-error.jsp    /staging/app/
COPY ${DEPENDENCIES}/index.jsp            /staging/app/
COPY ${DEPENDENCIES}/log4j2.xml           /staging/app/
#################################################


######################################################################################################
FROM adoptopenjdk/openjdk12:alpine-jre
ARG API_NAME

LABEL maintainer="fabri1983dockerid"

ENV CATALINA_HOME=/opt/tomcat
    
ENV LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$CATALINA_HOME/lib

# Download ffmpeg as a package (last version always, otherwise you need to build from source)
# Download libs used by Tomcat native
RUN apk add --no-cache ffmpeg apr openssl && \
    rm -rf /var/cache/apk/*

# Copy from symbolic link created in previous image
COPY --from=STAGING-TOMCAT $CATALINA_HOME $CATALINA_HOME

# Copy staged files into Tomcat's webapp folder
COPY --from=STAGING-WAR /staging/app ${CATALINA_HOME}/webapps/${API_NAME}

EXPOSE 8080

ENTRYPOINT exec ${CATALINA_HOME}/bin/catalina.sh run