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对于人脸检测的应用来说,OpenJDK的官方镜像是不够用的,因为用java实现人脸检测需要一个关键技术:javacv,在javacv运行过程中需要用到opencv的一些本地库,因此需要在运行环境中安装opencv
如下图所示,一个人脸检测应用自下而上由以下六部分构成,如果将底部的操作系统、JDK、OpenCV做成基础镜像就方便多了,咱们开发应用的时候只要需关注上面三层即可,而上面三层不就是个普通的maven工程吗?
之所以选择CentOS作为操作系统,是因为平时工作中最常用的就是它了
纵观OpenJDK官方的各种镜像,并没有发现CentOS作为操作系统的,因此自己动手吧,思路很简单:找到OpenJDK的Dockerfile文件,把它的基础镜像换成CentOS7.6即可
以下是Dockerfile的所有内容,可见核心是根据不同的操作系统下载文件然后安装,逻辑简单清晰就不多说了:
FROM centos:7.6.1810 RUN set -eux; \ yum install -y \ gzip \ tar \ binutils \ freetype fontconfig \ ; ENV JAVA_HOME /usr/java/openjdk-8 ENV PATH $JAVA_HOME/bin:$PATH # Default to UTF-8 file.encoding ENV LANG C.UTF-8 RUN set -eux; \ \ arch="$(objdump="$(command -v objdump)" && objdump --file-headers "$objdump" | awk -F '[:,]+[[:space:]]+' '$1 == "architecture" { print $2 }')"; \ case "$arch" in \ 'i386:x86-64') \ downloadUrl='https://github.com/AdoptOpenJDK/openjdk8-upstream-binaries/releases/download/jdk8u292-b10/OpenJDK8U-jdk_x64_linux_8u292b10.tar.gz'; \ ;; \ 'aarch64') \ downloadUrl='https://github.com/AdoptOpenJDK/openjdk8-upstream-binaries/releases/download/jdk8u292-b10/OpenJDK8U-jdk_aarch64_linux_8u292b10.tar.gz'; \ ;; \ *) echo >&2 "error: unsupported architecture: '$arch'"; exit 1 ;; \ esac; \ \ curl -fL -o openjdk.tgz "$downloadUrl"; \ curl -fL -o openjdk.tgz.asc "$downloadUrl.sign"; \ \ export GNUPGHOME="$(mktemp -d)"; \ # pre-fetch Andrew Haley's (the OpenJDK 8 and 11 Updates OpenJDK project lead) key so we can verify that the OpenJDK key was signed by it # (https://github.com/docker-library/openjdk/pull/322#discussion_r286839190) # we pre-fetch this so that the signature it makes on the OpenJDK key can survive "import-clean" in gpg gpg --batch --keyserver keyserver.ubuntu.com --recv-keys EAC843EBD3EFDB98CC772FADA5CD6035332FA671; \ # TODO find a good link for users to verify this key is right (https://mail.openjdk.java.net/pipermail/jdk-updates-dev/2019-April/000951.html is one of the only mentions of it I can find); perhaps a note added to https://adoptopenjdk.net/upstream.html would make sense? # no-self-sigs-only: https://salsa.debian.org/debian/gnupg2/commit/c93ca04a53569916308b369c8b218dad5ae8fe07 gpg --batch --keyserver keyserver.ubuntu.com --keyserver-options no-self-sigs-only --recv-keys CA5F11C6CE22644D42C6AC4492EF8D39DC13168F; \ gpg --batch --list-sigs --keyid-format 0xLONG CA5F11C6CE22644D42C6AC4492EF8D39DC13168F \ | tee /dev/stderr \ | grep '0xA5CD6035332FA671' \ | grep 'Andrew Haley'; \ gpg --batch --verify openjdk.tgz.asc openjdk.tgz; \ rm -rf "$GNUPGHOME"; \ \ mkdir -p "$JAVA_HOME"; \ tar --extract \ --file openjdk.tgz \ --directory "$JAVA_HOME" \ --strip-components 1 \ --no-same-owner \ ; \ rm openjdk.tgz*; \ \ rm -rf "$JAVA_HOME/jre/lib/security/cacerts"; \ # see "update-ca-trust" script which creates/maintains this cacerts bundle ln -sT /etc/pki/ca-trust/extracted/java/cacerts "$JAVA_HOME/jre/lib/security/cacerts"; \ \ # https://github.com/oracle/docker-images/blob/a56e0d1ed968ff669d2e2ba8a1483d0f3acc80c0/OracleJava/java-8/Dockerfile#L17-L19 ln -sfT "$JAVA_HOME" /usr/java/default; \ ln -sfT "$JAVA_HOME" /usr/java/latest; \ for bin in "$JAVA_HOME/bin/"*; do \ base="$(basename "$bin")"; \ [ ! -e "/usr/bin/$base" ]; \ alternatives --install "/usr/bin/$base" "$base" "$bin" 20000; \ done; \ \ # basic smoke test javac -version; \ java -version
写完之后执行docker build -t bolingcavalry/centos7.6-jdk8:0.0.1 .即可生成镜像,如果您有hub.docker.com的账号,还可以将其推送到中央仓库,给更多人使用
用history命令看看镜像内容,详情如下,合计五百多兆,已经不小了:
CN0014009475M:~ will$ docker history bolingcavalry/centos7.6-jdk8:0.0.1 IMAGE CREATED CREATED BY SIZE COMMENT a5dead4a6505 2 days ago /bin/sh -c set -eux; arch="$(objdump… 209MB <missing> 2 days ago /bin/sh -c #(nop) ENV LANG=C.UTF-8 0B <missing> 2 days ago /bin/sh -c #(nop) ENV PATH=/usr/java/openjd… 0B <missing> 2 days ago /bin/sh -c #(nop) ENV JAVA_HOME=/usr/java/o… 0B <missing> 2 days ago /bin/sh -c set -eux; yum install -y … 144MB <missing> 2 years ago /bin/sh -c #(nop) CMD ["/bin/bash"] 0B <missing> 2 years ago /bin/sh -c #(nop) LABEL org.label-schema.sc… 0B <missing> 2 years ago /bin/sh -c #(nop) ADD file:54b004357379717df… 202MB
docker pull bolingcavalry/centos7.6-jdk8:0.0.3
FROM bolingcavalry/centos7.6-jdk8:0.0.1 RUN echo "export LC_ALL=en_US.UTF-8" >> /etc/profile \ && source /etc/profile RUN set -eux; \ yum install -y \ make \ cmake \ gcc \ gcc-c++ \ gtk+-devel \ gimp-devel \ gimp-devel-tools \ gimp-help-browser \ zlib-devel \ libtiff-devel \ libjpeg-devel \ libpng-devel \ gstreamer-devel \ libavc1394-devel \ libraw1394-devel \ libdc1394-devel \ jasper-devel \ jasper-utils \ swig \ python \ libtool \ nasm \ build-essential \ ant \ unzip \ ; RUN set -eux; \ curl -fL -o opencv-3.4.3.zip https://codeload.github.com/opencv/opencv/zip/3.4.3; \ unzip opencv-3.4.3.zip; \ rm -rf opencv-3.4.3.zip; \ cd opencv-3.4.3; \ mkdir build; \ cd build; \ cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local ..; \ make; \ make install; \ cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -DBUILD_TESTS=OFF ..;\ make -j8; \ make install
CN0014009475M:~ will$ docker history bolingcavalry/opencv3.4.3:0.0.3 IMAGE CREATED CREATED BY SIZE COMMENT f0306d7a2594 2 days ago /bin/sh -c set -eux; curl -fL -o opencv-… 2.99GB <missing> 2 days ago /bin/sh -c set -eux; yum install -y … 638MB <missing> 2 days ago /bin/sh -c echo "export LC_ALL=en_US.UTF-8" … 1.84kB <missing> 2 days ago /bin/sh -c set -eux; arch="$(objdump… 209MB <missing> 2 days ago /bin/sh -c #(nop) ENV LANG=C.UTF-8 0B <missing> 2 days ago /bin/sh -c #(nop) ENV PATH=/usr/java/openjd… 0B <missing> 2 days ago /bin/sh -c #(nop) ENV JAVA_HOME=/usr/java/o… 0B <missing> 2 days ago /bin/sh -c set -eux; yum install -y … 144MB <missing> 2 years ago /bin/sh -c #(nop) CMD ["/bin/bash"] 0B <missing> 2 years ago /bin/sh -c #(nop) LABEL org.label-schema.sc… 0B <missing> 2 years ago /bin/sh -c #(nop) ADD file:54b004357379717df… 202MB
docker pull bolingcavalry/opencv3.4.3:0.0.3
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