官方安装说明文档：https://docs.docker.com/engine/install/centos/
安装yum-utils软件包（提供yum-config-manager 实用程序）并设置稳定的存储库。
yum install -y yum-utils yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
Step1.安装最新版本的Docker Engine和容器，或转到下一步以安装特定版本：
yum install docker-ce docker-ce-cli containerd.ioStep2.启动Docker
systemctl start docker使用ifconfig命令，会查看到多出来一张虚拟网卡，如下图所示
在容器中，启动服务基本上是基于镜像的。
参数解释：-it:交互式的 -d：到后台 -p:暴露到端口
冒号前面的80是用户访问的，后面的80是镜像服务启动的默认端口
–name起名，若没有起名，系统会自动起一个名字。
这种情况说明80端口被占用，冒号前面的80应该修改为其他端口，比如82.
这种情况说明web80名字刚刚被上面的操作占用了，我们把web80修改为web81.
这种情况表明httpd服务已经启动，暴露端口号为82，名称为web81.
**使用浏览器访问docker容器所在的计算机对应的ip地址，并输入端口号82，如能成功显示下图所示的页面，说明httpd服务成功运行。
我们再来再来启动一个httpd服务试试看吧！
设定暴露端口号为83，名称为83.
docker run -it -d -p 83:80 --name web83 httpd如您能看到下图所示的测试页面，则说明httpd服务启动正常。
进去之后可以执行一些简单的命令，但不能执行shell命令，比如vim(vi)命令。
查看效果
Step1.在删除容器之前，先停止容器：
docker stop web80Step2.查看web80的状态：
docker ps -aStep3.删除web80：
docker rm web80网页链接：http://hub.docker.com/
直接搜索需要查找的镜像名称即可，不需要注册账号。
可以看到，上图红框所示的是我们刚刚通过docker search httpd命令查找到的官方httpd镜像。
点进来之后，网页会提示通过什么命令来下载httpd镜像。
如何下载一个2.4.46版本的httpd镜像呢？
docker pull httpd:2.4.46查看现有的docker镜像：
docker images这些镜像存放在了容器里面
数据持久化的目的：为了把数据放在容器外面，而不是存储在容器内部。因为一旦容器被删除，数据也会跟着消失。
共享可以通过NFS服务实现。
-v参数可以把容器里面的目录和容器外面的目录进行映射。
/usr/local/apache2/htdocs/ 是容器里面的目录Step1.在根目录下创建目录
mkdir /web82Step2.创建一个html文件
vi /web82/index.html
wq保存退出
Step3.映射文件到web服务器
docker run -it -d -p 82:80 --name web82 -v /web82:/usr/local/apache2/htdocs/ httpd 模板：docker run -it -d -p 82:80 --name [自定义名称] -v /[本地目录]:[容器目录] [使用何种服务]查看效果，如下图
如果index.html的内容发生更改，只要直接刷新浏览器就可以看到最新的index页面。
vi /web82/index.html
查看Dockfile的语法：
***链接：***https://github.com/docker-library/httpd/blob/077141ee37fca63972292c562ec0f632d0f831b1/2.4/Dockerfile
参数解释：FROM debian:buster-slim 基于debian镜像
ENV:设置环境变量
RUN:运行命令
WORKDIR:工作目录
STOPSIGNAL:停止信号
EXPOSE：暴露的端口
CMD:容器启动的时候执行的命令
FROM debian:buster-slim # add our user and group first to make sure their IDs get assigned consistently, regardless of whatever dependencies get added #RUN groupadd -r www-data && useradd -r --create-home -g www-data www-data ENV HTTPD_PREFIX /usr/local/apache2 ENV PATH $HTTPD_PREFIX/bin:$PATH RUN mkdir -p "$HTTPD_PREFIX" \ && chown www-data:www-data "$HTTPD_PREFIX" WORKDIR $HTTPD_PREFIX # install httpd runtime dependencies # https://httpd.apache.org/docs/2.4/install.html#requirements RUN set -eux; \ apt-get update; \ apt-get install -y --no-install-recommends \ libaprutil1-ldap \ ; \ rm -rf /var/lib/apt/lists/* ENV HTTPD_VERSION 2.4.46 ENV HTTPD_SHA256 740eddf6e1c641992b22359cabc66e6325868c3c5e2e3f98faf349b61ecf41ea # https://httpd.apache.org/security/vulnerabilities_24.html ENV HTTPD_PATCHES="" # see https://httpd.apache.org/docs/2.4/install.html#requirements RUN set -eux; \ \ # mod_http2 mod_lua mod_proxy_html mod_xml2enc # https://anonscm.debian.org/cgit/pkg-apache/apache2.git/tree/debian/control?id=adb6f181257af28ee67af15fc49d2699a0080d4c savedAptMark="$(apt-mark showmanual)"; \ apt-get update; \ apt-get install -y --no-install-recommends \ bzip2 \ ca-certificates \ dirmngr \ dpkg-dev \ gcc \ gnupg \ libapr1-dev \ libaprutil1-dev \ libbrotli-dev \ libcurl4-openssl-dev \ libjansson-dev \ liblua5.2-dev \ libnghttp2-dev \ libpcre3-dev \ libssl-dev \ libxml2-dev \ make \ wget \ zlib1g-dev \ ; \ rm -r /var/lib/apt/lists/*; \ \ ddist() { \ local f="$1"; shift; \ local distFile="$1"; shift; \ local success=; \ local distUrl=; \ for distUrl in \ # https://issues.apache.org/jira/browse/INFRA-8753?focusedCommentId=14735394#comment-14735394 'https://www.apache.org/dyn/closer.cgi?action=download&filename=' \ # if the version is outdated (or we're grabbing the .asc file), we might have to pull from the dist/archive :/ https://www-us.apache.org/dist/ \ https://www.apache.org/dist/ \ https://archive.apache.org/dist/ \ ; do \ if wget -O "$f" "$distUrl$distFile" && [ -s "$f" ]; then \ success=1; \ break; \ fi; \ done; \ [ -n "$success" ]; \ }; \ \ ddist 'httpd.tar.bz2' "httpd/httpd-$HTTPD_VERSION.tar.bz2"; \ echo "$HTTPD_SHA256 *httpd.tar.bz2" | sha256sum -c -; \ \ # see https://httpd.apache.org/download.cgi#verify ddist 'httpd.tar.bz2.asc' "httpd/httpd-$HTTPD_VERSION.tar.bz2.asc"; \ export GNUPGHOME="$(mktemp -d)"; \ # $ docker run --rm buildpack-deps:buster-curl bash -c 'wget -qO- https://downloads.apache.org/httpd/KEYS | gpg --batch --import &> /dev/null && gpg --batch --list-keys --with-fingerprint --with-colons' | awk -F: '$1 == "pub" && $2 == "-" { pub = 1 } pub && $1 == "fpr" { fpr = $10 } $1 == "sub" { pub = 0 } pub && fpr && $1 == "uid" && $2 == "-" { print "#", $10; print "\t\t" fpr " \\"; pub = 0 }' for key in \ # Rodent of Unusual Size (DSA) <coar@ACM.Org> DE29FB3971E71543FD2DC049508EAEC5302DA568 \ # Rodent of Unusual Size <coar@ACM.Org> 13155B0E9E634F42BF6C163FDDBA64BA2C312D2F \ # Jim Jagielski <jim@apache.org> 8B39757B1D8A994DF2433ED58B3A601F08C975E5 \ # Dean Gaudet <dgaudet@apache.org> 31EE1A81B8D066548156D37B7D6DBFD1F08E012A \ # Cliff Woolley <jwoolley@apache.org> A10208FEC3152DD7C0C9B59B361522D782AB7BD1 \ # Cliff Woolley <jwoolley@virginia.edu> 3DE024AFDA7A4B15CB6C14410F81AA8AB0D5F771 \ # Graham Leggett <minfrin@apache.org> EB138C6AF0FC691001B16D93344A844D751D7F27 \ # Roy T. Fielding <fielding@gbiv.com> CBA5A7C21EC143314C41393E5B968010E04F9A89 \ # Justin R. Erenkrantz <jerenkrantz@apache.org> 3C016F2B764621BB549C66B516A96495E2226795 \ # Aaron Bannert <abannert@kuci.org> 937FB3994A242BA9BF49E93021454AF0CC8B0F7E \ # Brad Nicholes <bnicholes@novell.com> EAD1359A4C0F2D37472AAF28F55DF0293A4E7AC9 \ # Sander Striker <striker@apache.org> 4C1EADADB4EF5007579C919C6635B6C0DE885DD3 \ # Greg Stein <gstein@lyra.org> 01E475360FCCF1D0F24B9D145D414AE1E005C9CB \ # Andre Malo <nd@apache.org> 92CCEF0AA7DD46AC3A0F498BCA6939748103A37E \ # Erik Abele <erik@codefaktor.de> D395C7573A68B9796D38C258153FA0CD75A67692 \ # Astrid Kessler (Kess) <kess@kess-net.de> FA39B617B61493FD283503E7EED1EA392261D073 \ # Joe Schaefer <joe@sunstarsys.com> 984FB3350C1D5C7A3282255BB31B213D208F5064 \ # Stas Bekman <stas@stason.org> FE7A49DAA875E890B4167F76CCB2EB46E76CF6D0 \ # Paul Querna <chip@force-elite.com> 39F6691A0ECF0C50E8BB849CF78875F642721F00 \ # Colm MacCarthaigh <colm.maccarthaigh@heanet.ie> 29A2BA848177B73878277FA475CAA2A3F39B3750 \ # Ruediger Pluem <rpluem@apache.org> 120A8667241AEDD4A78B46104C042818311A3DE5 \ # Nick Kew <nick@webthing.com> 453510BDA6C5855624E009236D0BC73A40581837 \ # Philip M. Gollucci <pgollucci@p6m7g8.com> 0DE5C55C6BF3B2352DABB89E13249B4FEC88A0BF \ # Bojan Smojver <bojan@rexursive.com> 7CDBED100806552182F98844E8E7E00B4DAA1988 \ # Issac Goldstand <margol@beamartyr.net> A8BA9617EF3BCCAC3B29B869EDB105896F9522D8 \ # "Guenter Knauf" ("CODE SIGNING KEY") <fuankg@apache.org> 3E6AC004854F3A7F03566B592FF06894E55B0D0E \ # Jeff Trawick (CODE SIGNING KEY) <trawick@apache.org> 5B5181C2C0AB13E59DA3F7A3EC582EB639FF092C \ # Jim Jagielski (Release Signing Key) <jim@apache.org> A93D62ECC3C8EA12DB220EC934EA76E6791485A8 \ # Eric Covener <covener@apache.org> 65B2D44FE74BD5E3DE3AC3F082781DE46D5954FA \ # Yann Ylavic <ylavic@apache.org> 8935926745E1CE7E3ED748F6EC99EE267EB5F61A \ # Daniel Ruggeri (http\x3a//home.apache.org/~druggeri/) <druggeri@apache.org> B9E8213AEFB861AF35A41F2C995E35221AD84DFF \ # Daniel Ruggeri (http\x3a//home.apache.org/~druggeri/) <druggeri@apache.org> E3480043595621FE56105F112AB12A7ADC55C003 \ # Joe Orton (Release Signing Key) <jorton@apache.org> 93525CFCF6FDFFB3FD9700DD5A4B10AE43B56A27 \ ; do \ gpg --batch --keyserver ha.pool.sks-keyservers.net --recv-keys "$key"; \ done; \ gpg --batch --verify httpd.tar.bz2.asc httpd.tar.bz2; \ command -v gpgconf && gpgconf --kill all || :; \ rm -rf "$GNUPGHOME" httpd.tar.bz2.asc; \ \ mkdir -p src; \ tar -xf httpd.tar.bz2 -C src --strip-components=1; \ rm httpd.tar.bz2; \ cd src; \ \ patches() { \ while [ "$#" -gt 0 ]; do \ local patchFile="$1"; shift; \ local patchSha256="$1"; shift; \ ddist "$patchFile" "httpd/patches/apply_to_$HTTPD_VERSION/$patchFile"; \ echo "$patchSha256 *$patchFile" | sha256sum -c -; \ patch -p0 < "$patchFile"; \ rm -f "$patchFile"; \ done; \ }; \ patches $HTTPD_PATCHES; \ \ gnuArch="$(dpkg-architecture --query DEB_BUILD_GNU_TYPE)"; \ CFLAGS="$(dpkg-buildflags --get CFLAGS)"; \ CPPFLAGS="$(dpkg-buildflags --get CPPFLAGS)"; \ LDFLAGS="$(dpkg-buildflags --get LDFLAGS)"; \ ./configure \ --build="$gnuArch" \ --prefix="$HTTPD_PREFIX" \ --enable-mods-shared=reallyall \ --enable-mpms-shared=all \ # enable the same hardening flags as Debian # - https://salsa.debian.org/apache-team/apache2/blob/87db7de4e59683fb03e97900f078d06ef2292748/debian/rules#L19-21 # - https://salsa.debian.org/apache-team/apache2/blob/87db7de4e59683fb03e97900f078d06ef2292748/debian/rules#L115 --enable-pie \ CFLAGS="-pipe $CFLAGS" \ CPPFLAGS="$CPPFLAGS" \ LDFLAGS="-Wl,--as-needed $LDFLAGS" \ ; \ make -j "$(nproc)"; \ make install; \ \ cd ..; \ rm -r src man manual; \ \ sed -ri \ -e 's!^(\s*CustomLog)\s+\S+!\1 /proc/self/fd/1!g' \ -e 's!^(\s*ErrorLog)\s+\S+!\1 /proc/self/fd/2!g' \ -e 's!^(\s*TransferLog)\s+\S+!\1 /proc/self/fd/1!g' \ "$HTTPD_PREFIX/conf/httpd.conf" \ "$HTTPD_PREFIX/conf/extra/httpd-ssl.conf" \ ; \ \ # reset apt-mark's "manual" list so that "purge --auto-remove" will remove all build dependencies apt-mark auto '.*' > /dev/null; \ [ -z "$savedAptMark" ] || apt-mark manual $savedAptMark; \ find /usr/local -type f -executable -exec ldd '{}' ';' \ | awk '/=>/ { print $(NF-1) }' \ | sort -u \ | xargs -r dpkg-query --search \ | cut -d: -f1 \ | sort -u \ | xargs -r apt-mark manual \ ; \ apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \ \ # smoke test httpd -v # https://httpd.apache.org/docs/2.4/stopping.html#gracefulstop STOPSIGNAL SIGWINCH COPY httpd-foreground /usr/local/bin/ EXPOSE 80 CMD ["httpd-foreground"]swam（docker官方提供，比较简单）
k8s（kubernetes）：谷歌开源出来的，功能比较强大
yaml语言
这就是为什么启动完成容器后，什么都没做就可以访问那个容器。
