Docker - 02 创建镜像 Dockerfile 指令速查表

docker build 命令

参数 说明 示例
-f 指定 Dockerfile 位置 docker build -f /path/to/a/Dockerfile .
-t 指定镜像名称 docker build -t shykes/myapp:v1.1.2 .
-t -t 生成多个镜像 docker build -t shykes/myapp:v1.1.2 -t shykes/myapp:latest .

Dockerfile 指令速查表

命令 说明 示例
FROM 基于这个Image开始 FROM nginx:latest
ENV 环境变量 ENV localfile /usr/local/nginx
RUN 新层中执行命令 RUN /bin/bash -c 'source $HOME/.bashrc; echo $HOME'
LABEL 设置metadata LABEL version="1.0"
MAINTAINER 维护者 (deprecated) MAINTAINER ducafecat
EXPOSE 声明容器监听端口 EXPOSE 80 443
ADD 复制文件 ADD ./dist ${foo}/html
COPY 复制文件 COPY ./dist ${foo}/html
ENTRYPOINT 容器启动时执行指令 CMD ["ls"]
CMD 容器启动时执行指令默认值 CMD ["-la"]
VOLUME 挂载点 VOLUME ["/data"]
USER 指定操作用户 USER www
WORKDIR 设置工作目录 WORKDIR /path/to/workdir
ARG 设置参数 ARG user=www
ONBUILD 镜像被From时触发 ONBUILD RUN /bin/bash -c 'echo ONBUILD ...'
STOPSIGNAL 停止信号退出 STOPSIGNAL SIGTERM
HEALTHCHECK 检查容器的健康状况 HEALTHCHECK --interval=5m --timeout=3s CMD curl -f http://localhost/ exit 1
SHELL 覆盖默认shell SHELL ["powershell", "-command"]

.dockerignore 文件

参数 说明
#comment 忽略
/temp 纯文件/somedir/temporary.txt被排除,目录/somedir /temp也是如此。
//temp* /somedir/subdir/temporary.txt被排除。
temp? /tempa和/tempb被排除在外。
!README.md README.md 文件不会被排除

例子 - nginx 镜像

FROM debian:stretch-slim

LABEL maintainer="NGINX Docker Maintainers <docker-maint@nginx.com>"

ENV NGINX_VERSION 1.15.2-1~stretch
ENV NJS_VERSION   1.15.2.0.2.2-1~stretch

RUN set -x \
    && apt-get update \
    && apt-get install --no-install-recommends --no-install-suggests -y gnupg1 apt-transport-https ca-certificates \
    && \
    NGINX_GPGKEY=573BFD6B3D8FBC641079A6ABABF5BD827BD9BF62; \
    found=''; \
    for server in \
        ha.pool.sks-keyservers.net \
        hkp://keyserver.ubuntu.com:80 \
        hkp://p80.pool.sks-keyservers.net:80 \
        pgp.mit.edu \
    ; do \
        echo "Fetching GPG key $NGINX_GPGKEY from $server"; \
        apt-key adv --keyserver "$server" --keyserver-options timeout=10 --recv-keys "$NGINX_GPGKEY" && found=yes && break; \
    done; \
    test -z "$found" && echo >&2 "error: failed to fetch GPG key $NGINX_GPGKEY" && exit 1; \
    apt-get remove --purge --auto-remove -y gnupg1 && rm -rf /var/lib/apt/lists/* \
    && dpkgArch="$(dpkg --print-architecture)" \
    && nginxPackages=" \
        nginx=${NGINX_VERSION} \
        nginx-module-xslt=${NGINX_VERSION} \
        nginx-module-geoip=${NGINX_VERSION} \
        nginx-module-image-filter=${NGINX_VERSION} \
        nginx-module-njs=${NJS_VERSION} \
    " \
    && case "$dpkgArch" in \
        amd64|i386) \
# arches officialy built by upstream
            echo "deb https://nginx.org/packages/mainline/debian/ stretch nginx" >> /etc/apt/sources.list.d/nginx.list \
            && apt-get update \
            ;; \
        *) \
# we're on an architecture upstream doesn't officially build for
# let's build binaries from the published source packages
            echo "deb-src https://nginx.org/packages/mainline/debian/ stretch nginx" >> /etc/apt/sources.list.d/nginx.list \
            \
# new directory for storing sources and .deb files
            && tempDir="$(mktemp -d)" \
            && chmod 777 "$tempDir" \
# (777 to ensure APT's "_apt" user can access it too)
            \
# save list of currently-installed packages so build dependencies can be cleanly removed later
            && savedAptMark="$(apt-mark showmanual)" \
            \
# build .deb files from upstream's source packages (which are verified by apt-get)
            && apt-get update \
            && apt-get build-dep -y $nginxPackages \
            && ( \
                cd "$tempDir" \
                && DEB_BUILD_OPTIONS="nocheck parallel=$(nproc)" \
                    apt-get source --compile $nginxPackages \
            ) \
# we don't remove APT lists here because they get re-downloaded and removed later
            \
# reset apt-mark's "manual" list so that "purge --auto-remove" will remove all build dependencies
# (which is done after we install the built packages so we don't have to redownload any overlapping dependencies)
            && apt-mark showmanual | xargs apt-mark auto > /dev/null \
            && { [ -z "$savedAptMark" ] || apt-mark manual $savedAptMark; } \
            \
# create a temporary local APT repo to install from (so that dependency resolution can be handled by APT, as it should be)
            && ls -lAFh "$tempDir" \
            && ( cd "$tempDir" && dpkg-scanpackages . > Packages ) \
            && grep '^Package: ' "$tempDir/Packages" \
            && echo "deb [ trusted=yes ] file://$tempDir ./" > /etc/apt/sources.list.d/temp.list \
# work around the following APT issue by using "Acquire::GzipIndexes=false" (overriding "/etc/apt/apt.conf.d/docker-gzip-indexes")
#   Could not open file /var/lib/apt/lists/partial/_tmp_tmp.ODWljpQfkE_._Packages - open (13: Permission denied)
#   ...
#   E: Failed to fetch store:/var/lib/apt/lists/partial/_tmp_tmp.ODWljpQfkE_._Packages  Could not open file /var/lib/apt/lists/partial/_tmp_tmp.ODWljpQfkE_._Packages - open (13: Permission denied)
            && apt-get -o Acquire::GzipIndexes=false update \
            ;; \
    esac \
    \
    && apt-get install --no-install-recommends --no-install-suggests -y \
                        $nginxPackages \
                        gettext-base \
    && apt-get remove --purge --auto-remove -y apt-transport-https ca-certificates && rm -rf /var/lib/apt/lists/* /etc/apt/sources.list.d/nginx.list \
    \
# if we have leftovers from building, let's purge them (including extra, unnecessary build deps)
    && if [ -n "$tempDir" ]; then \
        apt-get purge -y --auto-remove \
        && rm -rf "$tempDir" /etc/apt/sources.list.d/temp.list; \
    fi

# forward request and error logs to docker log collector
RUN ln -sf /dev/stdout /var/log/nginx/access.log \
    && ln -sf /dev/stderr /var/log/nginx/error.log

EXPOSE 80

STOPSIGNAL SIGTERM

CMD ["nginx", "-g", "daemon off;"]

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