2017级系统综合实践第2次实践作业

前言

上一次作业同学们实现了docker环境的安装和基本配置，已经能够从docker的官方镜像仓库中拉取镜像，初步实现了入门。然而，从官方仓库拉取的镜像是最简单的镜像，在实际应用中经常需要根据需求额外修改镜像，这就涉及到了镜像的定制。在docker中我们可以使用Dockerfile文件实现自定义镜像，本次作业需要完成2个Dockerfile编写实践，掌握编写Dockerfile文件的基本方法。

实现一个自定义的web容器服务

推荐apache或nginx，要求标明镜像作者信息，安装必要的工具以方便维护；设定你自己的web存放目录，安全起见，请将默认的监听端口80更改为你自定义的端口，并且声明暴露的端口，容器启动时，能直接进入web代码的存放目录。

获取Nginx镜像

查看是否安装了nginx

安装完成后，我们可以使用以下命令来运行 nginx 容器

可以通过浏览器可以直接访问 8080 端口的 nginx 服务

进入nginx容器并查看其配置信息

创建dockerfile

default.conf文件

dockerfile文件

index.html文件

三个文件都写好了之后，在该目录下运行构建镜像

其中，lqynginx是所要构建镜像的名称，.表示上下文，千万不能漏掉

验证查看lqynginx是否构建成功

启动lqynginx容器并映射端口

通过浏览器查看nginx网页（访问5039端口）

实现一个自定义的数据库容器服务

可选择Mysql，Mariadb等，要求标明镜像作者信息，为了方便维护，需要能够查看容器内的配置信息，包括但不限于网络、应用配置文件等。在环境变量中设置好数据库的root密码且不允许空密码登录，创建一个测试数据库，指定用户名和密码。

从镜像库中获取mysql:5.7镜像并查看

创建mysql文件夹

创建dockerfile

#基础镜像
FROM mysql:5.7
#维护人信息
MAINTAINER LQY
#设置免密登录
ENV MYSQL_ALLOW_EMPTY_PASSWORD yes
#经所需文件放到容器中
COPY setup.sh /home/liqingyu/mysql/setup.sh
COPY schema.sql /home/liqingyu/mysql/schema.sql
COPY privileges.sql /home/liqingyu/mysql/privileges.sql
#设置容器启动是执行的命令
CMD ["sh", "/home/liqingyu/mysql/setup.sh"]

编写容器启动脚本setup.sh：

#!/bin/bash
set -e
#查看mysql服务的状态，方便调试，这条语句可以删除
echo `service mysql status`

echo '1.启动mysql...'
#启动mysql
service mysql start
sleep 3
echo `service mysql status`

echo '2.开始导入数据...'
#导入数据
mysql < /mysql/schema.sql
echo '3.导入数据完毕...'

sleep 3
echo `service mysql status`

#重新设置mysql密码
echo '4.开始修改密码...'
mysql < /home/liqingyu/mysql/privileges.sql
echo '5.修改密码完毕...'

echo `service mysql status`
echo 'mysql容器启动完毕，且数据导入成功'

tail -f /dev/null

创建需要导入数据的mysql脚本命令schema.sql：

-- 创建数据库
create database `docker_mysql` default character set utf8 collate utf8_general_ci;
 
use docker_mysql;
 
-- 建表
DROP TABLE IF EXISTS test;
 
CREATE TABLE test (
 `id` bigint(20) NOT NULL,
 `name` varchar(255) DEFAULT ""
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
 
-- 插入数据
INSERT INTO test (`id`, `name`)
VALUES
  (031702539,'lqy');

创建mysql权限设置命令privileges.sql：

use mysql;
select host,user from user;
-- 因为mysql版本是5.7，因此新建用户为如下命令：
create user docker identified by '123456';
--将docker_mysql数据库的权限授权给创建的lqy用户，密码为123456:
grant all on docker_mysql.* to docker@'%' identified by '123456' with grant option;
-- 这一条命令一定要有：
flush privileges;

【注】dockerfile、setup.sh、schema.sql、privileges.sql这四个文件都放在主目录下的mysql文件下

构建镜像

运行容器 ，将端口映射到3306

到目前为止，除了文件配置出错外，我做的还算顺利吧，但是后面因为Ubuntu的硬盘容量满了的问题导致我创建的容器一直闪退，所以在此处提醒后来的同学--创建虚拟机给的硬盘容量一定要大一点！(50G左右差不多吧)

运行成功之后执行exec进入容器

sudo docker exec -it be30f8159b6b /bin/bash

使用docker用户登陆

mysql -u docker -p (这里的docker和你配置文件privileges.sql中的名字相关，不一定是docker)

切换至docker_mysql数据库：

use docker_mysql

查询user表并exit退出mysql

查看容器配置信息

sudo docker inspect [容器ID]

[
    {
        "Id": "a1eb1491689b515e4496ae1b105b2edbf647a8efbe1f3798b0c36f97f7a61667",
        "Created": "2020-04-23T04:23:27.565452688Z",
        "Path": "docker-entrypoint.sh",
        "Args": [
            "sh",
            "/home/liqingyu/mysql/setup.sh"
        ],
        "State": {
            "Status": "running",
            "Running": true,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 5983,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2020-04-23T04:23:28.683887516Z",
            "FinishedAt": "0001-01-01T00:00:00Z"
        },
        "Image": "sha256:0f2319941fa25c668ad5c8e7c05c87151fde17e11811396beda3885c399c2e47",
        "ResolvConfPath": "/var/lib/docker/containers/a1eb1491689b515e4496ae1b105b2edbf647a8efbe1f3798b0c36f97f7a61667/resolv.conf",
        "HostnamePath": "/var/lib/docker/containers/a1eb1491689b515e4496ae1b105b2edbf647a8efbe1f3798b0c36f97f7a61667/hostname",
        "HostsPath": "/var/lib/docker/containers/a1eb1491689b515e4496ae1b105b2edbf647a8efbe1f3798b0c36f97f7a61667/hosts",
        "LogPath": "/var/lib/docker/containers/a1eb1491689b515e4496ae1b105b2edbf647a8efbe1f3798b0c36f97f7a61667/a1eb1491689b515e4496ae1b105b2edbf647a8efbe1f3798b0c36f97f7a61667-json.log",
        "Name": "/lqymysql",
        "RestartCount": 0,
        "Driver": "overlay2",
        "Platform": "linux",
        "MountLabel": "",
        "ProcessLabel": "",
        "AppArmorProfile": "docker-default",
        "ExecIDs": null,
        "HostConfig": {
            "Binds": null,
            "ContainerIDFile": "",
            "LogConfig": {
                "Type": "json-file",
                "Config": {}
            },
            "NetworkMode": "default",
            "PortBindings": {
                "3306/tcp": [
                    {
                        "HostIp": "",
                        "HostPort": "3306"
                    }
                ]
            },
            "RestartPolicy": {
                "Name": "no",
                "MaximumRetryCount": 0
            },
            "AutoRemove": false,
            "VolumeDriver": "",
            "VolumesFrom": null,
            "CapAdd": null,
            "CapDrop": null,
            "Capabilities": null,
            "Dns": [],
            "DnsOptions": [],
            "DnsSearch": [],
            "ExtraHosts": null,
            "GroupAdd": null,
            "IpcMode": "private",
            "Cgroup": "",
            "Links": null,
            "OomScoreAdj": 0,
            "PidMode": "",
            "Privileged": false,
            "PublishAllPorts": false,
            "ReadonlyRootfs": false,
            "SecurityOpt": null,
            "UTSMode": "",
            "UsernsMode": "",
            "ShmSize": 67108864,
            "Runtime": "runc",
            "ConsoleSize": [
                0,
                0
            ],
            "Isolation": "",
            "CpuShares": 0,
            "Memory": 0,
            "NanoCpus": 0,
            "CgroupParent": "",
            "BlkioWeight": 0,
            "BlkioWeightDevice": [],
            "BlkioDeviceReadBps": null,
            "BlkioDeviceWriteBps": null,
            "BlkioDeviceReadIOps": null,
            "BlkioDeviceWriteIOps": null,
            "CpuPeriod": 0,
            "CpuQuota": 0,
            "CpuRealtimePeriod": 0,
            "CpuRealtimeRuntime": 0,
            "CpusetCpus": "",
            "CpusetMems": "",
            "Devices": [],
            "DeviceCgroupRules": null,
            "DeviceRequests": null,
            "KernelMemory": 0,
            "KernelMemoryTCP": 0,
            "MemoryReservation": 0,
            "MemorySwap": 0,
            "MemorySwappiness": null,
            "OomKillDisable": false,
            "PidsLimit": null,
            "Ulimits": null,
            "CpuCount": 0,
            "CpuPercent": 0,
            "IOMaximumIOps": 0,
            "IOMaximumBandwidth": 0,
            "MaskedPaths": [
                "/proc/asound",
                "/proc/acpi",
                "/proc/kcore",
                "/proc/keys",
                "/proc/latency_stats",
                "/proc/timer_list",
                "/proc/timer_stats",
                "/proc/sched_debug",
                "/proc/scsi",
                "/sys/firmware"
            ],
            "ReadonlyPaths": [
                "/proc/bus",
                "/proc/fs",
                "/proc/irq",
                "/proc/sys",
                "/proc/sysrq-trigger"
            ]
        },
        "GraphDriver": {
            "Data": {
                "LowerDir": "/var/lib/docker/overlay2/f57fc1aca42e95defd6ae63cd0b689a6b09380709479023c2efebf4ab5df1a80-init/diff:/var/lib/docker/overlay2/a72503b2d56f07e287248338284c59596b495ebcc289c163f5d351ed2f2037b5/diff:/var/lib/docker/overlay2/2669451c3ccb7d60a3c071aefd62d00ad18dfa2f1ad45637b54ff4bc605597d7/diff:/var/lib/docker/overlay2/9561ec6d28c7a3a20827e7861b938a5ddeb49c6b77fdbc87f87ce3421ef85ffb/diff:/var/lib/docker/overlay2/314cfa96c36595f4ea24bb776b4e0afe809121a24fa09e20a0e1d29662658dc9/diff:/var/lib/docker/overlay2/47f83d6cf79fb3aaee1d9029dab9599ce534ce4c35bb38367eba05b3935bfd56/diff:/var/lib/docker/overlay2/fd39211c1f8b20c2f8204d75760ca778ad4f4655d89be7a920027b4378a2c49a/diff:/var/lib/docker/overlay2/73cf12fbecf0b395144e4cdcc1afa40f3f97a3fdc241f1d6a0a617dd7c503b88/diff:/var/lib/docker/overlay2/82e5208794a275ab8b83980a1cccc4ed07c2220053e2a3fc10c568288eba182a/diff:/var/lib/docker/overlay2/732b5139f7be03f107c92b17341f7d006d3b3fe230238d262ca9becfc6347faa/diff:/var/lib/docker/overlay2/ecb0f6e3c27d1ba78b8028437f542068ce9649a3f45a6b2f5db0213dde8a384d/diff:/var/lib/docker/overlay2/8e6bfa7e49c719773127fb4d16c35fde164dd2476e6d7aeb3b99a5b67b761ec0/diff:/var/lib/docker/overlay2/2bc0d9f29c00d6f293d6ae1c7ecd4055840bcfcdca2993f087754b55435b5f98/diff:/var/lib/docker/overlay2/76486d9cf91e95e107d0bea5bc81bfaf3760cd1e6486d53266aaddcba0c2a2a4/diff:/var/lib/docker/overlay2/1e827476cfaeb5d2cac109fb88afb8ade2338ab276c2f7321477b1b1592bc74a/diff",
                "MergedDir": "/var/lib/docker/overlay2/f57fc1aca42e95defd6ae63cd0b689a6b09380709479023c2efebf4ab5df1a80/merged",
                "UpperDir": "/var/lib/docker/overlay2/f57fc1aca42e95defd6ae63cd0b689a6b09380709479023c2efebf4ab5df1a80/diff",
                "WorkDir": "/var/lib/docker/overlay2/f57fc1aca42e95defd6ae63cd0b689a6b09380709479023c2efebf4ab5df1a80/work"
            },
            "Name": "overlay2"
        },
        "Mounts": [
            {
                "Type": "volume",
                "Name": "4d78089b0786945199e0f154e11a1cea89a1142bb93e10ad6b3e0474fb4a3a42",
                "Source": "/var/lib/docker/volumes/4d78089b0786945199e0f154e11a1cea89a1142bb93e10ad6b3e0474fb4a3a42/_data",
                "Destination": "/var/lib/mysql",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            }
        ],
        "Config": {
            "Hostname": "a1eb1491689b",
            "Domainname": "",
            "User": "",
            "AttachStdin": false,
            "AttachStdout": false,
            "AttachStderr": false,
            "ExposedPorts": {
                "3306/tcp": {},
                "33060/tcp": {}
            },
            "Tty": false,
            "OpenStdin": false,
            "StdinOnce": false,
            "Env": [
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
                "GOSU_VERSION=1.12",
                "MYSQL_MAJOR=5.7",
                "MYSQL_VERSION=5.7.29-1debian10",
                "MYSQL_ALLOW_EMPTY_PASSWORD=yes"
            ],
            "Cmd": [
                "sh",
                "/mysql/setup.sh"
            ],
            "Image": "lrmysql",
            "Volumes": {
                "/var/lib/mysql": {}
            },
            "WorkingDir": "",
            "Entrypoint": [
                "docker-entrypoint.sh"
            ],
            "OnBuild": null,
            "Labels": {}
        },
        "NetworkSettings": {
            "Bridge": "",
            "SandboxID": "904dcddd6885b32d231a0bd99cacc00c564e96797ced1f7fe133c76b098d77ba",
            "HairpinMode": false,
            "LinkLocalIPv6Address": "",
            "LinkLocalIPv6PrefixLen": 0,
            "Ports": {
                "3306/tcp": [
                    {
                        "HostIp": "0.0.0.0",
                        "HostPort": "3306"
                    }
                ],
                "33060/tcp": null
            },
            "SandboxKey": "/var/run/docker/netns/904dcddd6885",
            "SecondaryIPAddresses": null,
            "SecondaryIPv6Addresses": null,
            "EndpointID": "3ec448f16281c20febead242d6955351e7c2bde675e3c17bd4c3ab41baba8cd7",
            "Gateway": "172.17.0.1",
            "GlobalIPv6Address": "",
            "GlobalIPv6PrefixLen": 0,
            "IPAddress": "172.17.0.3",
            "IPPrefixLen": 16,
            "IPv6Gateway": "",
            "MacAddress": "02:42:ac:11:00:03",
            "Networks": {
                "bridge": {
                    "IPAMConfig": null,
                    "Links": null,
                    "Aliases": null,
                    "NetworkID": "5130acc46901ae45589989f722bf423a183cb280a2982f88c15c1eb085161508",
                    "EndpointID": "3ec448f16281c20febead242d6955351e7c2bde675e3c17bd4c3ab41baba8cd7",
                    "Gateway": "172.17.0.1",
                    "IPAddress": "172.17.0.3",
                    "IPPrefixLen": 16,
                    "IPv6Gateway": "",
                    "GlobalIPv6Address": "",
                    "GlobalIPv6PrefixLen": 0,
                    "MacAddress": "02:42:ac:11:00:03",
                    "DriverOpts": null
                }
            }
        }
    }
]

总结

因为配置文件写错，还有硬盘空间不足的问题（在进入数据库后面那一部分，借用了几张其他同学的截图），我耽误了不少时间，但是也对docker的各项指令和原理加深了印象。
还有就是
执行docker logs lqymysql命令查看出错也蛮关键的，可以节省大量改错的实践
最后 谢谢各位前辈们为不辞辛劳，身先士卒，为我们踩了无数的坑，谢谢你们！希望这种优良传统一直保持下去。