# 指定所构建镜像的基础镜像
FROM debian:buster-slim

# 指定生成镜像的元数据标签信息
LABEL maintainer="NGINX Docker Maintainers <docker-maint@nginx.com>"

# 指定环境变量
ENV NGINX_VERSION   1.18.0
ENV NJS_VERSION     0.4.0
ENV PKG_RELEASE     1~buster

# 运行指定命令
RUN set -x \
# create nginx user/group first, to be consistent throughout docker variants
    && addgroup --system --gid 101 nginx \
    && adduser --system --disabled-login --ingroup nginx --no-create-home --home /nonexistent --gecos "nginx user" --shell /bin/false --uid 101 nginx \
    && apt-get update \
    && apt-get install --no-install-recommends --no-install-suggests -y gnupg1 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=${NGINX_VERSION}-${PKG_RELEASE} \
        nginx-module-xslt=${NGINX_VERSION}-${PKG_RELEASE} \
        nginx-module-geoip=${NGINX_VERSION}-${PKG_RELEASE} \
        nginx-module-image-filter=${NGINX_VERSION}-${PKG_RELEASE} \
        nginx-module-njs=${NGINX_VERSION}.${NJS_VERSION}-${PKG_RELEASE} \
    " \
    && case "$dpkgArch" in \
        amd64|i386) \
# arches officialy built by upstream
            echo "deb https://nginx.org/packages/debian/ buster 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/debian/ buster 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 \
                        $nginxPackages \
                        gettext-base \
                        curl \
    && apt-get remove --purge --auto-remove -y && rm -rf /var/lib/apt/lists/* /etc/apt/sources.list.d/nginx.list \
    \
# if we have leftovers from building, let's purge them (including extra, unnecessary build deps)
    && if [ -n "$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

# make default server listen on ipv6
RUN sed -i -E 's,listen       80;,listen       80;\n    listen  [::]:80;,' \
        /etc/nginx/conf.d/default.conf

# 指定镜像内服务所监听的端口
EXPOSE 80

# 指定所创建镜像启动的容器接收退出的信号值
STOPSIGNAL SIGTERM

# 指定启动容器时默认执行的命令
CMD ["nginx", "-g", "daemon off;"]

二、Dockerfile格式

Dockerfile的格式如下：

# Comment
INSTRUCTION arguments

# Comment
RUN echo 'we are running some # of cool things'

# direc \
tive=value

# directive=value1
# directive=value2
FROM ImageName

FROM ImageName
# directive=value

# About my dockerfile
# directive=value
FROM ImageName

# unknowndirective=value
# knowndirective=value

# syntax=docker/dockerfile
# syntax=docker/dockerfile:1.0
# syntax=docker.io/docker/dockerfile:1
# syntax=docker/dockerfile:1.0.0-experimental
# syntax=example.com/user/repo:tag@sha256:abcdef...

FROM microsoft/nanoserver
COPY testfile.txt c:\\
RUN dir c:\

# escape=`

FROM microsoft/nanoserver
COPY testfile.txt c:\
RUN dir c:\

FROM busybox
ENV foo /bar
WORKDIR ${foo}   # WORKDIR /bar
ADD . $foo       # ADD . /bar
COPY \$foo /quux # COPY $foo /quux

ENV abc=hello
ENV abc=bye def=$abc
ENV ghi=$abc

ARG  CODE_VERSION=latest
FROM base:${CODE_VERSION}
CMD  /code/run-app

FROM extras:${CODE_VERSION}
CMD  /code/run-extras

ARG VERSION=latest
FROM busybox:$VERSION
ARG VERSION
RUN echo $VERSION > image_version

LABEL "com.example.vendor"="ACME Incorporated"
LABEL com.example.label-with-value="foo"
LABEL version="1.0"
LABEL description="This text illustrates \
that label-values can span multiple lines."

LABEL multi.label1="value1" multi.label2="value2" other="value3"

LABEL multi.label1="value1" \
      multi.label2="value2" \
      other="value3"

LABEL maintainer="SvenDowideit@home.org.au"

EXPOSE 80/tcp
EXPOSE 80/udp

docker run -p 80:80/tcp -p 80:80/udp ...

ENV myName John Doe
ENV myDog Rex The Dog
ENV myCat fluffy

ENV myName="John Doe" myDog=Rex\ The\ Dog \
    myCat=fluffy

FROM microsoft/windowsservercore
# 在容器中创建Windows用户
RUN net user /add patrick
# 为后续命令设置用户名
USER patrick

WORKDIR /a
WORKDIR b
WORKDIR c
RUN pwd