Docker镜像、容器管理-笔记2

镜像操作

镜像（image）是Docker三大核心概念中最为重要的，自Docker诞生之日起“镜像”就是相关社区最为热门的关键词。 Docker运行容器前需要本地存在对应的镜像，如果镜像没保存在本地，Docker会尝试先从默认镜像仓库下载（默认使用Docker Hub公共注册服务器的仓库），用户也可以通过配置，使用自定义的镜像仓库。

1、镜像搜索

通过docker search image_name命令搜索镜像。通常较为常用的参数有

--automated=true|false：仅显示自动创建的镜像，默认为否；
--no-trunc=true|false：输出信息不截断显示，默认为否；
-s, --stars=X：根据镜像的星级进行搜索

比如搜索centos镜像，星级为10或者以上。从左到右，显示依次为：镜像名、描述、星级、是否为官方、是否为自动创建。

2、拉取镜像

通过docker pull images_name:tag即可拉取需要的镜像。默认的tag（标签是latest）

如拉取一个httpd的镜像（这里我不指定tag标签，默认就是latest，会显示拉取的进度）

执行docker images可以查看到现有的镜像（里面有刚刚获取的httpd镜像）

3、查看镜像信息

通过docker inspect images_name可以查看某个镜像的信息

[root@centos7f ~]# docker inspect httpd
[
    {
        "Id": "sha256:11426a19f1a28d6491041aef1e1a7a2dcaa188d0165ae495de7d8fc1bf3e164f",
        "RepoTags": [
            "httpd:latest"
        ],
        "RepoDigests": [
            "httpd@sha256:8c84e065bdf72b4909bd55a348d5e91fe265e08d6b28ed9104bfdcac9206dcc8"
        ],
        "Parent": "",
        "Comment": "",
        "Created": "2018-07-31T16:49:48.488308431Z",
        "Container": "8d9716b97c51721cce2f7450eea9622ec9d97c8760098550f7f1cf8cddd94061",
        "ContainerConfig": {
            "Hostname": "8d9716b97c51",
            "Domainname": "",
            "User": "",
            "AttachStdin": false,
            "AttachStdout": false,
            "AttachStderr": false,
            "ExposedPorts": {
                "80/tcp": {}
            },
            "Tty": false,
            "OpenStdin": false,
            "StdinOnce": false,
            "Env": [
                "PATH=/usr/local/apache2/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
                "HTTPD_PREFIX=/usr/local/apache2",
                "NGHTTP2_VERSION=1.18.1-1",
                "OPENSSL_VERSION=1.0.2l-1~bpo8+1",
                "HTTPD_VERSION=2.4.34",
                "HTTPD_SHA256=fa53c95631febb08a9de41fd2864cfff815cf62d9306723ab0d4b8d7aa1638f0",
                "HTTPD_PATCHES=",
                "APACHE_DIST_URLS=https://www.apache.org/dyn/closer.cgi?action=download&filename= \thttps://www-us.apache.org/dist/ \thttps://www.apache.org/dist/ \thttps://archive.apache.org/dist/"
            ],
            "Cmd": [
                "/bin/sh",
                "-c",
                "#(nop) ",
                "CMD [\"httpd-foreground\"]"
            ],
            "ArgsEscaped": true,
            "Image": "sha256:c237180f28409d28401f1f634e784c940bb89d15e4de5db35ca5f320aed423b2",
            "Volumes": null,
            "WorkingDir": "/usr/local/apache2",
            "Entrypoint": null,
            "OnBuild": [],
            "Labels": {}
        },
        "DockerVersion": "17.06.2-ce",
        "Author": "",
        "Config": {
            "Hostname": "",
            "Domainname": "",
            "User": "",
            "AttachStdin": false,
            "AttachStdout": false,
            "AttachStderr": false,
            "ExposedPorts": {
                "80/tcp": {}
            },
            "Tty": false,
            "OpenStdin": false,
            "StdinOnce": false,
            "Env": [
                "PATH=/usr/local/apache2/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
                "HTTPD_PREFIX=/usr/local/apache2",
                "NGHTTP2_VERSION=1.18.1-1",
                "OPENSSL_VERSION=1.0.2l-1~bpo8+1",
                "HTTPD_VERSION=2.4.34",
                "HTTPD_SHA256=fa53c95631febb08a9de41fd2864cfff815cf62d9306723ab0d4b8d7aa1638f0",
                "HTTPD_PATCHES=",
                "APACHE_DIST_URLS=https://www.apache.org/dyn/closer.cgi?action=download&filename= \thttps://www-us.apache.org/dist/ \thttps://www.apache.org/dist/ \thttps://archive.apache.org/dist/"
            ],
            "Cmd": [
                "httpd-foreground"
            ],
            "ArgsEscaped": true,
            "Image": "sha256:c237180f28409d28401f1f634e784c940bb89d15e4de5db35ca5f320aed423b2",
            "Volumes": null,
            "WorkingDir": "/usr/local/apache2",
            "Entrypoint": null,
            "OnBuild": [],
            "Labels": null
        },
        "Architecture": "amd64",
        "Os": "linux",
        "Size": 177559099,
        "VirtualSize": 177559099,
        "GraphDriver": {
            "Data": {
                "LowerDir": "/var/lib/docker/overlay2/e8a7d936a146f00002daad342da591eb4ff3c52b94361f62fe160949668df94f/diff:/var/lib/docker/overlay2/0497e7522cf60cc840d184f1f75a88e45fccedeb50f9685c72ba2f4e0334843b/diff:/var/lib/docker/overlay2/a71b868c28231bfcf73126a5df47157182b0414243f282a198770a22eea3713a/diff:/var/lib/docker/overlay2/e243b6e4b235b79969aff4fca1ba8521d1c7fc505c77d7d07d7ab52e95d960da/diff:/var/lib/docker/overlay2/dfa918fa4630779aaa319c0c833c9bf6b40d237e77a32b3e79574b843b78bff1/diff:/var/lib/docker/overlay2/5c0c1f37210838240c1e6aaa7a0ac2abee872450025d89df4a719cd2aeea21f4/diff",
                "MergedDir": "/var/lib/docker/overlay2/91f6e0aabf12bcdd5628447fabc919f0039f5e7bd7153382cad6ef413ccd5ed0/merged",
                "UpperDir": "/var/lib/docker/overlay2/91f6e0aabf12bcdd5628447fabc919f0039f5e7bd7153382cad6ef413ccd5ed0/diff",
                "WorkDir": "/var/lib/docker/overlay2/91f6e0aabf12bcdd5628447fabc919f0039f5e7bd7153382cad6ef413ccd5ed0/work"
            },
            "Name": "overlay2"
        },
        "RootFS": {
            "Type": "layers",
            "Layers": [
                "sha256:dd1eb1fd7e08dc9bda0cbea31a89196c453cb218bea80ce64eeb19fadc98d262",
                "sha256:f6ff89d562dc5b83d425e3a8768a580f4f7cde78f4b73e1f0adb3fd417c0a846",
                "sha256:611673f0c323fcac4130e893672e60d6b53a6e7c5b5890139f734d7f6e9dd6bc",
                "sha256:74e07a1c6b076bad4d917bde97391a7a565409445ace712ff6f26ae4f04b5b33",
                "sha256:94519f51ae61e88862ce4cb142d17a2bf4cf2f4aa36b286e0933f423c1939cff",
                "sha256:dcaeabd68175a017bd22be178535663ba9576eca061067f252039523527f424b",
                "sha256:28eaf9ee6b41f5f72eecbef3f09474a496bcb5cfefd718a1865cf74733a6def0"
            ]
        },
        "Metadata": {
            "LastTagTime": "0001-01-01T00:00:00Z"
        }
    }
]

注意：docker inspect输出的是json格式的信息

如：下面两条命令输出了httpd镜像开放了80端口、使用的是amd64的架构

4、删除镜像

使用docker rmi images_name命令

第一条命令没有执行成功，因为基于这个镜像上存在一个容器。通过-f选项可强制删除这个镜像，强制删除后，容器也将被删除，所以-f选项需谨慎使用。

5、创建一个镜像

commit方法：可根据一个容器创建一个镜像

下图中我首先启动了一个镜像，然后使用commit方法创建一个镜像叫httpd_server、tag是01。通过docker images可以查看到我创建的镜像

commit的参数：

-a指定创建镜像的author（作者）

-m提交消息

基于模板导入的方法

这里有很多docker的模板供下载http://download.openvz.org/template/precreated/（下载速度很慢，不是很建议这么做）

下载完了，可以执行

cat 模板 | docker import - images_name：tag

这样你就能通过模板创建了一个镜像。

书写Dockerfile创建模板（建议做法）

详细操作请关注后面的博客

6、存出和载入镜像

存出

通过docker save命令可以存出一个镜像，通过这个命令可以将同样的环境给开发、运维、测试使用，避免了一些因为工作环境带了的麻烦

载入

为了验证效果我将原有的jdeathe/centos-ssh删除了，然后载入刚刚存出的centos.tar。载入的命令为docker load < images.tar

7、上传镜像到docker hub

首先你需要注册有个docker hub的账号

注册地址https://hub.docker.com

执行docker login即可登录

想要上传到你的docker hub账户内，首先要给镜像打标签。记住标签打的是自己的hub账号名，然后跟上仓库名，tag。如果你的docker hub没有这个仓库，会自动创建该仓库。

然后直接push打了标签的镜像即可

这里给大家看一下结果

容器操作

查看你的容器

docker ps命令可以查看你当前运行的容器，而docker ps -a或者docker ps --all可以查看所有容器 

创建容器

docker create images_name:tag可以创建一个容器。这里创建容器会随机给一个容器名称，很不利于管理，但是注意在创建容器时docker会返还给你一个容器的ID。

启动容器

docker start container_name/container_id

新建的同时启动容器

执行docker run images_name可以根据一个镜像创建一个容器并运行。

下图中，我用run命令基于jdeathe/centos-ssh运行了一个容器，然后让容器执行了echo "hello,I'm running"命令。然后容器会自动停止运行

守护态运行容器

我们在使用docker容器的时候大多时候都会让docker一直运行提供应用服务的，很少会让他运行执行一个命令就直接关闭。docker run -itd可以让容器在docker的回台运行，提供服务。

进入/连接容器

通过上面的命令让容器在后台运行了，所以连接容器执行命令是需要的

通过docker exec -it container_name /bin/bash 命令即可连接到正在运行的容器

显示容器的信息

[root@centos7f ~]# docker inspect 002b96bb30a9
[
    {
        "Id": "002b96bb30a92e73b71b9430e9ddef168ed0e098a5a7bb460fb04b4ca0286c3b",
        "Created": "2018-08-18T13:31:18.963206183Z",
        "Path": "/bin/bash",
        "Args": [],
        "State": {
            "Status": "running",
            "Running": true,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 114840,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2018-08-18T13:31:19.305350229Z",
            "FinishedAt": "0001-01-01T00:00:00Z",
            "Health": {
                "Status": "unhealthy",
                "FailingStreak": 39,
                "Log": [
                    {
                        "Start": "2018-08-18T21:31:40.692311294+08:00",
                        "End": "2018-08-18T21:31:40.780482004+08:00",
                        "ExitCode": 1,
                        "Output": ""
                    },
                    {
                        "Start": "2018-08-18T21:31:41.301262289+08:00",
                        "End": "2018-08-18T21:31:41.388515509+08:00",
                        "ExitCode": 1,
                        "Output": ""
                    },
                    {
                        "Start": "2018-08-18T21:31:41.910073234+08:00",
                        "End": "2018-08-18T21:31:41.997176118+08:00",
                        "ExitCode": 1,
                        "Output": ""
                    },
                    {
                        "Start": "2018-08-18T21:31:42.518304445+08:00",
                        "End": "2018-08-18T21:31:42.605189606+08:00",
                        "ExitCode": 1,
                        "Output": ""
                    },
                    {
                        "Start": "2018-08-18T21:31:43.127178763+08:00",
                        "End": "2018-08-18T21:31:43.21354527+08:00",
                        "ExitCode": 1,
                        "Output": ""
                    }
                ]
            }
        },
        "Image": "sha256:563e45ee6e1243335785f558dbb566791e5ac5bd293aafc5c75e5b0743eaa888",
        "ResolvConfPath": "/var/lib/docker/containers/002b96bb30a92e73b71b9430e9ddef168ed0e098a5a7bb460fb04b4ca0286c3b/resolv.conf",
        "HostnamePath": "/var/lib/docker/containers/002b96bb30a92e73b71b9430e9ddef168ed0e098a5a7bb460fb04b4ca0286c3b/hostname",
        "HostsPath": "/var/lib/docker/containers/002b96bb30a92e73b71b9430e9ddef168ed0e098a5a7bb460fb04b4ca0286c3b/hosts",
        "LogPath": "/var/lib/docker/containers/002b96bb30a92e73b71b9430e9ddef168ed0e098a5a7bb460fb04b4ca0286c3b/002b96bb30a92e73b71b9430e9ddef168ed0e098a5a7bb460fb04b4ca0286c3b-json.log",
        "Name": "/cocky_ptolemy",
        "RestartCount": 0,
        "Driver": "overlay2",
        "Platform": "linux",
        "MountLabel": "",
        "ProcessLabel": "",
        "AppArmorProfile": "",
        "ExecIDs": [
            "02039efcbf2bb4b4b8f1a88187144ef13fe3873035efe13dff00b3afcdeb1059"
        ],
        "HostConfig": {
            "Binds": null,
            "ContainerIDFile": "",
            "LogConfig": {
                "Type": "json-file",
                "Config": {}
            },
            "NetworkMode": "default",
            "PortBindings": {},
            "RestartPolicy": {
                "Name": "no",
                "MaximumRetryCount": 0
            },
            "AutoRemove": false,
            "VolumeDriver": "",
            "VolumesFrom": null,
            "CapAdd": null,
            "CapDrop": null,
            "Dns": [],
            "DnsOptions": [],
            "DnsSearch": [],
            "ExtraHosts": null,
            "GroupAdd": null,
            "IpcMode": "shareable",
            "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,
            "DiskQuota": 0,
            "KernelMemory": 0,
            "MemoryReservation": 0,
            "MemorySwap": 0,
            "MemorySwappiness": null,
            "OomKillDisable": false,
            "PidsLimit": 0,
            "Ulimits": null,
            "CpuCount": 0,
            "CpuPercent": 0,
            "IOMaximumIOps": 0,
            "IOMaximumBandwidth": 0,
            "MaskedPaths": [
                "/proc/acpi",
                "/proc/kcore",
                "/proc/keys",
                "/proc/latency_stats",
                "/proc/timer_list",
                "/proc/timer_stats",
                "/proc/sched_debug",
                "/proc/scsi",
                "/sys/firmware"
            ],
            "ReadonlyPaths": [
                "/proc/asound",
                "/proc/bus",
                "/proc/fs",
                "/proc/irq",
                "/proc/sys",
                "/proc/sysrq-trigger"
            ]
        },
        "GraphDriver": {
            "Data": {
                "LowerDir": "/var/lib/docker/overlay2/3cda10e35c399bd1362edc91b9d1ae9b27a76c198aaf9407b06fe3ebc521d200-init/diff:/var/lib/docker/overlay2/53a5b0930c3c8500d36135247d0820d14ab9249c07df1e745dc61fdf9829f638/diff:/var/lib/docker/overlay2/c8e5e31d4c76e171e86a8ac1b88d7a76798d6588b45c9eee8f9430fa0eb72681/diff:/var/lib/docker/overlay2/6b67f4e966ab81cee54f1c2b2438ca1dcb49aaa600fa724acdf9fc2b32e2ad36/diff:/var/lib/docker/overlay2/27fa1c8e7cfc942ee5df37b210ce9020ef9dc1439bd114e915183e0a8a731b6a/diff:/var/lib/docker/overlay2/5b946c5b08c008f219caa0703770d3a0bae213b07346a30d00db4c3aaaaec3d0/diff:/var/lib/docker/overlay2/2f939ad9a322e1471b17693fa89936d341a04359dbc5e2ac155e888b15b5e0e9/diff:/var/lib/docker/overlay2/f47a7753c7d4889dc79fa7edf005733d816eafcdbb60d83f6e1fcb551117e408/diff:/var/lib/docker/overlay2/e5af324a45dc5c414841328ef55e3ee3aed7738c100de81a06887c9abfae43e8/diff:/var/lib/docker/overlay2/b992eefb82fb8035c96de66a66def764b09c8a24b4b977817cf6545476a6cc07/diff:/var/lib/docker/overlay2/b97cd8b38d9f15c08bcd4c1589e8a0c8f8d617429986d61713a7b96183cdcc25/diff:/var/lib/docker/overlay2/392aa202ea4b1eb42b229082ee607d827cc42933e2507f5dc50f6d67f84f9331/diff:/var/lib/docker/overlay2/bbb0e0b3b6a8da11ffb6c7825f87f87b18cf3310a7ab1d64020abb037c6d4807/diff:/var/lib/docker/overlay2/16d8286164ccebe3b1b43d266519ced560165833e33bbc49150ff4384306e39a/diff:/var/lib/docker/overlay2/b3ba97cbdaac36a329b4349e13a7875de424b24363b39f86ac84883db5199a2d/diff",
                "MergedDir": "/var/lib/docker/overlay2/3cda10e35c399bd1362edc91b9d1ae9b27a76c198aaf9407b06fe3ebc521d200/merged",
                "UpperDir": "/var/lib/docker/overlay2/3cda10e35c399bd1362edc91b9d1ae9b27a76c198aaf9407b06fe3ebc521d200/diff",
                "WorkDir": "/var/lib/docker/overlay2/3cda10e35c399bd1362edc91b9d1ae9b27a76c198aaf9407b06fe3ebc521d200/work"
            },
            "Name": "overlay2"
        },
        "Mounts": [],
        "Config": {
            "Hostname": "002b96bb30a9",
            "Domainname": "",
            "User": "",
            "AttachStdin": false,
            "AttachStdout": false,
            "AttachStderr": false,
            "ExposedPorts": {
                "22/tcp": {}
            },
            "Tty": true,
            "OpenStdin": true,
            "StdinOnce": false,
            "Env": [
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
                "SSH_AUTHORIZED_KEYS=",
                "SSH_AUTOSTART_SSHD=true",
                "SSH_AUTOSTART_SSHD_BOOTSTRAP=true",
                "SSH_CHROOT_DIRECTORY=%h",
                "SSH_INHERIT_ENVIRONMENT=false",
                "SSH_SUDO=ALL=(ALL) ALL",
                "SSH_USER=app-admin",
                "SSH_USER_FORCE_SFTP=false",
                "SSH_USER_HOME=/home/%u",
                "SSH_USER_ID=500:500",
                "SSH_USER_PASSWORD=",
                "SSH_USER_PASSWORD_HASHED=false",
                "SSH_USER_SHELL=/bin/bash"
            ],
            "Cmd": [
                "/bin/bash"
            ],
            "Healthcheck": {
                "Test": [
                    "CMD",
                    "/usr/bin/healthcheck"
                ],
                "Interval": 500000000,
                "Timeout": 1000000000,
                "Retries": 5
            },
            "Image": "jdeathe/centos-ssh",
            "Volumes": null,
            "WorkingDir": "",
            "Entrypoint": null,
            "OnBuild": null,
            "Labels": {
                "build-date": "20170911",
                "install": "docker run --rm --privileged --volume /:/media/root jdeathe/centos-ssh:2.3.2 /usr/sbin/scmi install --chroot=/media/root --name=${NAME} --tag=2.3.2 --setopt='--volume {{NAME}}.config-ssh:/etc/ssh'",
                "license": "GPLv2",
                "maintainer": "James Deathe <[email protected]>",
                "name": "CentOS Base Image",
                "org.deathe.description": "CentOS-7 7.4.1708 x86_64 - SCL, EPEL and IUS Repositories / Supervisor / OpenSSH.",
                "org.deathe.license": "MIT",
                "org.deathe.name": "centos-ssh",
                "org.deathe.release": "jdeathe/centos-ssh:2.3.2",
                "org.deathe.url": "https://github.com/jdeathe/centos-ssh",
                "org.deathe.vendor": "jdeathe",
                "org.deathe.version": "2.3.2",
                "uninstall": "docker run --rm --privileged --volume /:/media/root jdeathe/centos-ssh:2.3.2 /usr/sbin/scmi uninstall --chroot=/media/root --name=${NAME} --tag=2.3.2 --setopt='--volume {{NAME}}.config-ssh:/etc/ssh'",
                "vendor": "CentOS"
            }
        },
        "NetworkSettings": {
            "Bridge": "",
            "SandboxID": "a28e769b9df4b9bba2c502c27a363bf69c0dc0127186d4287325239ef60cd2ed",
            "HairpinMode": false,
            "LinkLocalIPv6Address": "",
            "LinkLocalIPv6PrefixLen": 0,
            "Ports": {
                "22/tcp": null
            },
            "SandboxKey": "/var/run/docker/netns/a28e769b9df4",
            "SecondaryIPAddresses": null,
            "SecondaryIPv6Addresses": null,
            "EndpointID": "7458b19a71f455028c46a21b9b723639bea102556b1aa2e69a0964af2556671a",
            "Gateway": "172.17.0.1",
            "GlobalIPv6Address": "",
            "GlobalIPv6PrefixLen": 0,
            "IPAddress": "172.17.0.2",
            "IPPrefixLen": 16,
            "IPv6Gateway": "",
            "MacAddress": "02:42:ac:11:00:02",
            "Networks": {
                "bridge": {
                    "IPAMConfig": null,
                    "Links": null,
                    "Aliases": null,
                    "NetworkID": "7d4f6f5d62534239375305abc5e17709845a269f4dbb52d36b115b559963f594",
                    "EndpointID": "7458b19a71f455028c46a21b9b723639bea102556b1aa2e69a0964af2556671a",
                    "Gateway": "172.17.0.1",
                    "IPAddress": "172.17.0.2",
                    "IPPrefixLen": 16,
                    "IPv6Gateway": "",
                    "GlobalIPv6Address": "",
                    "GlobalIPv6PrefixLen": 0,
                    "MacAddress": "02:42:ac:11:00:02",
                    "DriverOpts": null
                }
            }
        }
    }
]

导出导入容器

首先导出一个容器

将容器导入到镜像

删除一个容器

通过docker rm container_name可以删除一个未运行的镜像，加上-f选项可以强制删除一个运行的镜像。

常用操作方法小结

1、docker run -itd --name centos001 jdeathe/centos-ssh /bin/bash

该命令可以让一个容器后台运行并未这个起名叫做centos001。

2、docker run -it --name centos002 

该命令可以运行一个容器，但是不是后台守护态。所以会直接连接进入该容器，可直接进行操作，直接执行exit退出该容器后，该容器就会停止。如果想退出，但是不停止容器，可以执行ctrl+p,然后紧跟着执行ctrl+q，让容器在退出后保持运行。