既然目标是定制满足自己需要的dockerfile，那么就来看看mysql的dockerfile长什么样。
dockerfile选择的是 https://github.com/mysql/mysql-docker/blob/mysql-server/5.7/Dockerfile
原因是这个比较短（捂脸）
关于dockerfile中的各种命令，可以查看官方文档，或者参考这篇： https://www.cnblogs.com/jie-fang/p/7927643.html
1 # Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved. 2 # 3 # This program is free software; you can redistribute it and/or modify 4 # it under the terms of the GNU General Public License as published by 5 # the Free Software Foundation; version 2 of the License. 6 # 7 # This program is distributed in the hope that it will be useful, 8 # but WITHOUT ANY WARRANTY; without even the implied warranty of 9 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 10 # GNU General Public License for more details. 11 # 12 # You should have received a copy of the GNU General Public License 13 # along with this program; if not, write to the Free Software 14 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 15 FROM oraclelinux:7-slim 16 17 ARG MYSQL_SERVER_PACKAGE_URL=https://repo.mysql.com/yum/mysql-5.7-community/docker/x86_64/mysql-community-server-minimal-5.7.23-1.el7.x86_64.rpm 18 ARG MYSQL_SHELL_PACKAGE_URL=https://repo.mysql.com/yum/mysql-tools-community/el/7/x86_64/mysql-shell-8.0.12-1.el7.x86_64.rpm 19 20 # Install server 21 RUN rpmkeys --import https://repo.mysql.com/RPM-GPG-KEY-mysql 22 && yum install -y $MYSQL_SERVER_PACKAGE_URL $MYSQL_SHELL_PACKAGE_URL libpwquality 23 && yum clean all 24 && mkdir /docker-entrypoint-initdb.d 25 26 VOLUME /var/lib/mysql 27 28 COPY docker-entrypoint.sh /entrypoint.sh 29 COPY healthcheck.sh /healthcheck.sh 30 ENTRYPOINT ["/entrypoint.sh"] 31 HEALTHCHECK CMD /healthcheck.sh 32 EXPOSE 3306 33060 33 CMD ["mysqld"]
咱们一行一行看。
FROM oraclelinux:7-slim
15行，这里是oracle自己的linux，不过看后面使用的是yum，我们自己配置的时候大概可以用centos代替。
ARG MYSQL_SERVER_PACKAGE_URL=https://repo.mysql.com/yum/mysql-5.7-community/docker/x86_64/mysql-community-server-minimal-5.7.23-1.el7.x86_64.rpm ARG MYSQL_SHELL_PACKAGE_URL=https://repo.mysql.com/yum/mysql-tools-community/el/7/x86_64/mysql-shell-8.0.12-1.el7.x86_64.rpm
17和18两行，定义了两个变量用来指向接下来需要用的rpm包的地址。
RUN rpmkeys --import https://repo.mysql.com/RPM-GPG-KEY-mysql && yum install -y $MYSQL_SERVER_PACKAGE_URL $MYSQL_SHELL_PACKAGE_URL libpwquality && yum clean all && mkdir /docker-entrypoint-initdb.d
21～24行，这里安装了mysql包。如果我们进行简化的话，rpmkeys和libpwquality都可以省略掉。
VOLUME /var/lib/mysql COPY docker-entrypoint.sh /entrypoint.sh COPY healthcheck.sh /healthcheck.sh ENTRYPOINT ["/entrypoint.sh"] HEALTHCHECK CMD /healthcheck.sh
26～31行，这里复制了需要的脚本文件，重点是entrypoint.sh。healthcheck如果进行简化的话也可以省略掉。
EXPOSE 3306 33060
32行规定了向主机暴露的端口号。如果不需要的话可以省略。另外注意，并不是expose了就可以用，还是需要在run的时候进行端口映射。
CMD ["mysqld"]
最后33行是dockerfile执行的启动命令（的参数）。
根据上面的分析，我们自己的dockerfile的mysql部分，大概应该是这样的：
FROM centos:7.2.1511 ARG MYSQL_SERVER_PACKAGE_URL=https://repo.mysql.com/yum/mysql-5.7-community/docker/x86_64/mysql-community-server-minimal-5.7.23-1.el7.x86_64.rpm ARG MYSQL_SHELL_PACKAGE_URL=https://repo.mysql.com/yum/mysql-tools-community/el/7/x86_64/mysql-shell-8.0.12-1.el7.x86_64.rpm RUN yum install -y --nogpgcheck $MYSQL_SERVER_PACKAGE_URL $MYSQL_SHELL_PACKAGE_URL COPY docker-entrypoint.sh /entrypoint.sh ENTRYPOINT ["/entrypoint.sh"] CMD ["mysqld"]
然后就可以先试试看了：
shell> docker build -t mysql_basic . Sending build context to Docker daemon 10.24kB Step 1/7 : FROM centos:7.2.1511 ---> ddc0fb7d7a72 Step 2/7 : ARG MYSQL_SERVER_PACKAGE_URL=https://repo.mysql.com/yum/mysql-5.7-community/docker/x86_64/mysql-community-server-minimal-5.7.23-1.el7.x86_64.rpm ---> Running in 3ff12f470551 Removing intermediate container 3ff12f470551 ---> a544211d9806 Step 3/7 : ARG MYSQL_SHELL_PACKAGE_URL=https://repo.mysql.com/yum/mysql-tools-community/el/7/x86_64/mysql-shell-8.0.12-1.el7.x86_64.rpm ---> Running in fa793935528a Removing intermediate container fa793935528a ---> ecc70ab46823 Step 4/7 : RUN yum install -y --nogpgcheck $MYSQL_SERVER_PACKAGE_URL $MYSQL_SHELL_PACKAGE_URL ---> Running in 6f3dd9f850f2 Loaded plugins: fastestmirror Examining /var/tmp/yum-root-2ratBJ/mysql-community-server-minimal-5.7.23-1.el7.x86_64.rpm: mysql-community-server-minimal-5.7.23-1.el7.x86_64 Marking /var/tmp/yum-root-2ratBJ/mysql-community-server-minimal-5.7.23-1.el7.x86_64.rpm to be installed Examining /var/tmp/yum-root-2ratBJ/mysql-shell-8.0.12-1.el7.x86_64.rpm: mysql-shell-8.0.12-1.el7.x86_64 Marking /var/tmp/yum-root-2ratBJ/mysql-shell-8.0.12-1.el7.x86_64.rpm to be installed Resolving Dependencies --> Running transaction check ---> Package mysql-community-server-minimal.x86_64 0:5.7.23-1.el7 will be installed --> Processing Dependency: libaio.so.1(LIBAIO_0.1)(64bit) for package: mysql-community-server-minimal-5.7.23-1.el7.x86_64 Determining fastest mirrors * base: mirror.hmc.edu * extras: mirror.nodesdirect.com * updates: mirror.teklinks.com --> Processing Dependency: libaio.so.1(LIBAIO_0.4)(64bit) for package: mysql-community-server-minimal-5.7.23-1.el7.x86_64 --> Processing Dependency: libnuma.so.1(libnuma_1.1)(64bit) for package: mysql-community-server-minimal-5.7.23-1.el7.x86_64 --> Processing Dependency: libnuma.so.1(libnuma_1.2)(64bit) for package: mysql-community-server-minimal-5.7.23-1.el7.x86_64 --> Processing Dependency: libaio.so.1()(64bit) for package: mysql-community-server-minimal-5.7.23-1.el7.x86_64 --> Processing Dependency: libnuma.so.1()(64bit) for package: mysql-community-server-minimal-5.7.23-1.el7.x86_64 ---> Package mysql-shell.x86_64 0:8.0.12-1.el7 will be installed --> Running transaction check ---> Package libaio.x86_64 0:0.3.109-13.el7 will be installed ---> Package numactl-libs.x86_64 0:2.0.9-7.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved ================================================================================ Package Arch Version Repository Size ================================================================================ Installing: mysql-community-server-minimal x86_64 5.7.23-1.el7 /mysql-community-server-minimal-5.7.23-1.el7.x86_64 67 M mysql-shell x86_64 8.0.12-1.el7 /mysql-shell-8.0.12-1.el7.x86_64 25 M Installing for dependencies: libaio x86_64 0.3.109-13.el7 base 24 k numactl-libs x86_64 2.0.9-7.el7 base 29 k Transaction Summary ================================================================================ Install 2 Packages (+2 Dependent packages) Total size: 92 M Total download size: 54 k Installed size: 92 M Downloading packages: -------------------------------------------------------------------------------- Total 33 kB/s | 54 kB 00:01 Running transaction check Running transaction test Transaction test succeeded Running transaction Installing : numactl-libs-2.0.9-7.el7.x86_64 1/4 Installing : libaio-0.3.109-13.el7.x86_64 2/4 Installing : mysql-community-server-minimal-5.7.23-1.el7.x86_64 3/4 Installing : mysql-shell-8.0.12-1.el7.x86_64 4/4 Verifying : mysql-community-server-minimal-5.7.23-1.el7.x86_64 1/4 Verifying : libaio-0.3.109-13.el7.x86_64 2/4 Verifying : numactl-libs-2.0.9-7.el7.x86_64 3/4 Verifying : mysql-shell-8.0.12-1.el7.x86_64 4/4 Installed: mysql-community-server-minimal.x86_64 0:5.7.23-1.el7 mysql-shell.x86_64 0:8.0.12-1.el7 Dependency Installed: libaio.x86_64 0:0.3.109-13.el7 numactl-libs.x86_64 0:2.0.9-7.el7 Complete! Removing intermediate container 6f3dd9f850f2 ---> e118192698af Step 5/7 : COPY docker-entrypoint.sh /entrypoint.sh ---> 1aab375ae211 Step 6/7 : ENTRYPOINT ["/entrypoint.sh"] ---> Running in 4c99517c3da0 Removing intermediate container 4c99517c3da0 ---> 54f44871daeb Step 7/7 : CMD ["mysqld"] ---> Running in f534cb3d8f0e Removing intermediate container f534cb3d8f0e ---> dc0ae9f1dc87 Successfully built dc0ae9f1dc87 Successfully tagged mysql_basic:latest
看看image
shell> docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
mysql_basic latest dc0ae9f1dc87 About a minute ago 400MB
跑起来看看
shell> docker run -d --name mysqlbasic mysql_basic shell> docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES a7efdfdaa91d mysql_basic "/entrypoint.sh mysq…" 5 seconds ago Up 3 seconds mysqlbasic
再看看docker里面的情况
docker exec -it mysqlbasic bash [root@a7efdfdaa91d /]# mysql ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)
哈哈access denied。上一篇说过的，第一次密码是随机生成的。那么我们来拿密码试试。
shell> docker logs mysqlbasic [Entrypoint] MySQL Docker Image 5.7.23-1.1.7 [Entrypoint] No password option specified for new database. [Entrypoint] A random onetime password will be generated. [Entrypoint] Initializing database [Entrypoint] Database initialized Warning: Unable to load '/usr/share/zoneinfo/iso3166.tab' as time zone. Skipping it. Warning: Unable to load '/usr/share/zoneinfo/zone.tab' as time zone. Skipping it. [Entrypoint] GENERATED ROOT PASSWORD: 0D0horOvZOHufUpuvAr0L]UkOBX3 [Entrypoint] ignoring /docker-entrypoint-initdb.d/* [Entrypoint] Server shut down [Entrypoint] Setting root user as expired. Password will need to be changed before database can be used. [Entrypoint] MySQL init process done. Ready for start up. [Entrypoint] Starting MySQL 5.7.23-1.1.7 [root@a7efdfdaa91d /]# mysql -uroot -p Enter password: Welcome to the MySQL monitor. Commands end with ; or g. Your MySQL connection id is 6 Server version: 5.7.23 Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or 'h' for help. Type 'c' to clear the current input statement. mysql>
成功的登录了root账号。这样，我们就把dockerfile里关键的部分提取出来，并且可以正常的build和run了。
接下来的问题，我们不能每次都先找随机生成的密码，然后再登录。所以我们要把mysql的初始化和启动服务的过程搞清楚。这样才能根据自己的要求进行修改。
接下来是下一篇的内容了！
PS：其实这种方法是有其本身的问题的……比如，很多时候，我们并不要把docker扔到后台运行，而是直接在前台运行一个bash。
那么我们来试试刚才build的image。
shell> docker run -it --name mysqlbasic mysql_basic /bin/bash [Entrypoint] MySQL Docker Image 5.7.23-1.1.7 [root@4e2ee3952247 /]# mysql ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
首先，我们和刚才用docker logs打出的log对比一下，发现这里Entrypoint只有一行。看来前后台的docker启动方式有一些不同。
那么这种不同导致了什么区别呢？尝试一下mysql。哎呀居然报了错误。
看来需要仔细研究一下entrypoint.sh到底干了什么。（就是下一篇的内容了！）