PodMan容器技术

容器 

容器技术

软件应用通常依赖于运行时环境提供的系统库、配置文件或服务。传统上，软件应用的运行时环境安装 在物理主机或虚拟机上运行的操作系统中。

然后，管理员在操作系统上安装应用依赖项。 在RHEL中，诸如 RPM 等打包系统可协助管理员管理相关依赖项。安装 httpd 软件包时，RPM 系统会确 保同时安装该软件包的正确库和其他依赖项。

以传统方式部署的软件应用的主要弊端时这些依赖项会受到运行时环境的束缚。应用需要的支持软件的 版本可能比操作系统提供的软件更旧或更新。

同样，同一系统上的两个应用可能需要同一软件互不兼容 的不同版本。 解决这些冲突的方式之一是将应用打包并作为容器进行部署。容器是由一个或多个与系统其余部分隔离 的进程组成的集合。软件容器是打包应用以简化其部署和管理的一种方式。

以实体集装箱为例，集装箱是打包和装运货物的标准方式。它作为一个箱子进行标记、装载、卸载，以 及从一个位置运输到另一个位置。集装箱中的内容与其他集装箱的内容隔离，因此互不影响。这些基本 原则也适用于软件容器。 RHEL 通过运用以下核心技术来支持容器：

• 用于资源管理的控制组（cgroup）
• 用于进程隔离的命名空间（namespace）
• 加强安全边界的SELinux 和 Secomp（安全计算模式）

Rootless 和 Rootful 容器

        在容器主机上，你可以 root 用户或普通非特权用户身份运行容器。由特权用户运行的容器称为 Rootful 容器。由非特权用户运行的容器称为 Rootless 容器。 Rootless 容器不允许使用通常为特权用户保留的系统资源，例如访问受限目录，或在受限端口（1024以 下的端口）上发布网络服务。此功能可防止潜在攻击者获取容器主机上的 root 权限。 

容器管理工具

RHEL 提供了一组容器工具，可用于在单一服务器上运行多个容器。

• podman 管理容器和容器镜像
• skopeo 检查、复制、删除和签署镜像
• buildah 创建容器镜像

这些工具与开放容器项目（OCI）兼容。借助这些工具，你可以管理由兼容 OCI 的容器引擎（如 Podman 或 Docker）创建的任何 Linux 容器。这些工具专门设计用于在单节点容器主机上的 RHEL 下运 行容器。

部署容器

Podman 实用程序 Podman 是来自 container-tools 元数据包的全功能容器引擎，用于管理开放容器计划容器和镜像。 podman 实用程序的运作不使用守护进程，因此开发人员无需系统上的特权用户账户来启动和停止容 器。Podman 提供多个子命令来与容器和镜像交互。以下列表显示了一些使用的子命令。

安装容器使用工具

# dnf install container-tools -y
# dnf info container-tools

从注册表下载容器镜像文件

[root@service ~]#  podman info
host:
  arch: amd64
  buildahVersion: 1.33.5
  cgroupControllers:
  - cpuset
  - cpu
  - io
  - memory
  - hugetlb
  - pids
  - rdma
  - misc
  cgroupManager: systemd
  cgroupVersion: v2
  conmon:
    package: conmon-2.1.10-1.el9.x86_64
    path: /usr/bin/conmon
    version: 'conmon version 2.1.10, commit: 5c6ed42ed821d0a028d0006e6f9c8a69ae0806ab'
  cpuUtilization:
    idlePercent: 75.99
    systemPercent: 6.7
    userPercent: 17.3
  cpus: 2
  databaseBackend: sqlite
  distribution:
    distribution: rhel
    version: "9.1"
  eventLogger: journald
  freeLocks: 2048
  hostname: service
  idMappings:
    gidmap: null
    uidmap: null
  kernel: 5.14.0-162.6.1.el9_1.x86_64
  linkmode: dynamic
  logDriver: journald
  memFree: 232144896
  memTotal: 1828413440
  networkBackend: netavark
  networkBackendInfo:
    backend: netavark
    dns:
      package: aardvark-dns-1.9.0-1.el9.x86_64
      path: /usr/libexec/podman/aardvark-dns
      version: aardvark-dns 1.9.0
    package: netavark-1.10.3-1.el9.x86_64
    path: /usr/libexec/podman/netavark
    version: netavark 1.10.3
  ociRuntime:
    name: crun
    package: crun-1.14.3-1.el9.x86_64
    path: /usr/bin/crun
    version: |-
      crun version 1.14.3
      commit: 1961d211ba98f532ea52d2e80f4c20359f241a98
      rundir: /run/user/0/crun
      spec: 1.0.0
      +SYSTEMD +SELINUX +APPARMOR +CAP +SECCOMP +EBPF +CRIU +YAJL
  os: linux
  pasta:
    executable: ""
    package: ""
    version: ""
  remoteSocket:
    exists: false
    path: /run/podman/podman.sock
  security:
    apparmorEnabled: false
    capabilities: CAP_CHOWN,CAP_DAC_OVERRIDE,CAP_FOWNER,CAP_FSETID,CAP_KILL,CAP_NET_BIND_SERVICE,CAP_SETFCAP,CAP_SETGID,CAP_SETPCAP,CAP_SETUID,CAP_SYS_CHROOT
    rootless: false
    seccompEnabled: true
    seccompProfilePath: /usr/share/containers/seccomp.json
    selinuxEnabled: true
  serviceIsRemote: false
  slirp4netns:
    executable: /usr/bin/slirp4netns
    package: slirp4netns-1.2.3-1.el9.x86_64
    version: |-
      slirp4netns version 1.2.3
      commit: c22fde291bb35b354e6ca44d13be181c76a0a432
      libslirp: 4.4.0
      SLIRP_CONFIG_VERSION_MAX: 3
      libseccomp: 2.5.2
  swapFree: 3140481024
  swapTotal: 4001361920
  uptime: 0h 24m 14.00s
  variant: ""
plugins:
  authorization: null
  log:
  - k8s-file
  - none
  - passthrough
  - journald
  network:
  - bridge
  - macvlan
  - ipvlan
  volume:
  - local
registries:
  search:
  - registry.access.redhat.com
  - registry.redhat.io
  - docker.io
store:
  configFile: /etc/containers/storage.conf
  containerStore:
    number: 0
    paused: 0
    running: 0
    stopped: 0
  graphDriverName: overlay
  graphOptions:
    overlay.mountopt: nodev,metacopy=on
  graphRoot: /var/lib/containers/storage
  graphRootAllocated: 17060331520
  graphRootUsed: 8712081408
  graphStatus:
    Backing Filesystem: xfs
    Native Overlay Diff: "false"
    Supports d_type: "true"
    Supports shifting: "false"
    Supports volatile: "true"
    Using metacopy: "true"
  imageCopyTmpDir: /var/tmp
  imageStore:
    number: 0
  runRoot: /run/containers/storage
  transientStore: false
  volumePath: /var/lib/containers/storage/volumes
version:
  APIVersion: 4.9.3-dev
  Built: 1707216158
  BuiltTime: Tue Feb  6 18:42:38 2024
  GitCommit: ""
  GoVersion: go1.21.3
  Os: linux
  OsArch: linux/amd64
  Version: 4.9.3-dev

 搜索镜像

[root@service ~]# podman search python
NAME                                                                                         DESCRIPTION
registry.access.redhat.com/ubi8/python-27                                                    Platform for building and running Python 2.7...
registry.access.redhat.com/ubi8/python-36                                                    Platform for building and running Python 3.6...
registry.access.redhat.com/ubi8/python-38                                                    Platform for building and running Python 3.8...
registry.access.redhat.com/ubi8/python-39                                                    Platform for building and running Python 3.9...
registry.access.redhat.com/ubi9/python-39                                                    rhcc_registry.access.redhat.com_ubi9/python-...
registry.access.redhat.com/ubi9/python-311                                                   rhcc_registry.access.redhat.com_ubi9/python-...
registry.access.redhat.com/openshift3/python-33-rhel7                                        Python 3.3 platform for building and running...
registry.access.redhat.com/ubi8/python-311                                                   rhcc_registry.access.redhat.com_ubi8/python-...
registry.access.redhat.com/rhscl/python-35-rhel7                                             Python 3.5 platform for building and running...
registry.access.redhat.com/rhscl/python-27-rhel7                                             Python 2.7 platform for building and running...
registry.access.redhat.com/rhscl/python-34-rhel7                                             Python 3.4 platform for building and running...
registry.access.redhat.com/rhscl/python-36-rhel7                                             Python 3.6 available as container is a base...
registry.access.redhat.com/ubi7/python-27                                                    Python 2.7 platform for building and running...
registry.access.redhat.com/ubi7/python-36                                                    Platform for building and running Python 3.6...
registry.access.redhat.com/ubi7/python-38                                                    Python 3.8 platform for building and running...
registry.access.redhat.com/codeready-workspaces/stacks-python                                "Red Hat CodeReady Workspaces- Python Stack...
registry.access.redhat.com/codeready-workspaces-beta/stacks-python                           Red Hat CodeReady Workspaces- Python Stack c...
registry.access.redhat.com/rhel7-atomic                                                      Red Hat Enterprise Linux Atomic Image is a m...
registry.access.redhat.com/rhel7/rhel-atomic                                                 Red Hat Enterprise Linux Atomic Image is a m...
registry.access.redhat.com/rhel-atomic                                                       Red Hat Enterprise Linux Atomic Image is a m...
registry.access.redhat.com/rhel7-minimal                                                     Red Hat Enterprise Linux Minimal Image is a...
registry.access.redhat.com/rhel-minimal                                                      Red Hat Enterprise Linux Minimal Image is a...
registry.access.redhat.com/rhel7-rhel-minimal                                                Red Hat Enterprise Linux Minimal Image is a...
registry.access.redhat.com/rhscl/s2i-base-rhel7                                              Base image delivers all the essential librar...
registry.access.redhat.com/ubi8/s2i-base                                                     Base image with essential libraries and tool...
registry.redhat.io/rhel8/python-27                                                           Python 2.7 available as container is a base...
registry.redhat.io/rhel8/python-36                                                           Python 3.6 available as container is a base...
registry.redhat.io/ubi8/python-27                                                            Platform for building and running Python 2.7...
registry.redhat.io/ubi8/python-36                                                            Platform for building and running Python 3.6...
registry.redhat.io/ubi8/python-38                                                            Platform for building and running Python 3.8...
registry.redhat.io/rhel8/python-38                                                           Platform for building and running Python 3.8...
registry.redhat.io/rhel8/python-39                                                           Platform for building and running Python 3.9...
registry.redhat.io/ubi8/python-39                                                            Platform for building and running Python 3.9...
registry.redhat.io/rhel9/python-39                                                           rhcc_registry.access.redhat.com_rhel9/python...
registry.redhat.io/ubi9/python-39                                                            rhcc_registry.access.redhat.com_ubi9/python-...
registry.redhat.io/rhel8/python-311                                                          rhcc_registry.access.redhat.com_rhel8/python...
registry.redhat.io/rhel9/python-311                                                          rhcc_registry.access.redhat.com_rhel9/python...
registry.redhat.io/ubi9/python-311                                                           rhcc_registry.access.redhat.com_ubi9/python-...
registry.redhat.io/openshift3/python-33-rhel7                                                Python 3.3 platform for building and running...
registry.redhat.io/ubi8/python-311                                                           rhcc_registry.access.redhat.com_ubi8/python-...
registry.redhat.io/ansible-automation-platform-21/ansible-python-base-rhel8                  Base python container for ansible-builder
registry.redhat.io/ansible-automation-platform-23/ansible-python-base-rhel8                  rhcc_registry.access.redhat.com_ansible-auto...
registry.redhat.io/ansible-automation-platform-23/ansible-python-toolkit-rhel8               rhcc_registry.access.redhat.com_ansible-auto...
registry.redhat.io/ansible-automation-platform-24/ansible-python-base-rhel9                  rhcc_registry.access.redhat.com_ansible-auto...
registry.redhat.io/ansible-automation-platform-24/ansible-python-toolkit-rhel9               rhcc_registry.access.redhat.com_ansible-auto...
registry.redhat.io/ansible-automation-platform-20-early-access/ansible-python-base-rhel8     Base python container for ansible-builder
registry.redhat.io/ansible-automation-platform-20-early-access/ansible-python-toolkit-rhel8  Python builder container for ansible-builder
registry.redhat.io/ansible-automation-platform-21/ansible-python-toolkit-rhel8               Python builder container for ansible-builder
registry.redhat.io/ansible-automation-platform-22/ansible-python-base-rhel8                  rhcc_registry.access.redhat.com_ansible-auto...
registry.redhat.io/ansible-automation-platform-22/ansible-python-toolkit-rhel8               rhcc_registry.access.redhat.com_ansible-auto...
docker.io/library/python                                                                     Python is an interpreted, interactive, objec...
docker.io/library/hylang                                                                     Hy is a Lisp dialect that translates express...
docker.io/library/pypy                                                                       PyPy is a fast, compliant alternative implem...
docker.io/bitnami/python                                                                     Bitnami Python Docker Image
docker.io/cimg/python                                                                        
docker.io/okteto/python                                                                      
docker.io/appdynamics/python-agent-init                                                      AppDynamics Repository for Python agent inst...
docker.io/rapidfort/python-chromedriver                                                      
docker.io/intel/python                                                                       
docker.io/pachyderm/python-build                                                             
docker.io/pachyderm/python-sdk-ci-testing                                                    
docker.io/airbyte/python-connector-base                                                      
docker.io/clearlinux/python                                                                  Python programming interpreted language with...
docker.io/faucet/python3                                                                      Python3 docker image for amd64
docker.io/openwhisk/python3action                                                            Apache OpenWhisk runtime for Python 3 Action...
docker.io/openwhisk/python2action                                                            Apache OpenWhisk runtime for Python v2 Actio...
docker.io/mirantis/python-operations-api                                                     https://mirantis.jira.com/browse/IT-40189
docker.io/opensuse/python                                                                    openSUSE base image with python
docker.io/submitty/python                                                                    Official Repository for Submitty Python Imag...
docker.io/okteto/python-fastapi                                                              
docker.io/fnndsc/python-poetry                                                               Python Poetry
docker.io/ubuntu/python                                                                      A chiselled Ubuntu rock with the Python runt...
docker.io/pipelinecomponents/python-safety                                                   Safety by pyup.io for Python in a container...
docker.io/openwhisk/python3aiaction                                                          Apache OpenWhisk runtime for Python 3 Action...
docker.io/okteto/python-job-launcher

下载镜像

[root@service ~]# podman pull docker.io/library/python
Trying to pull docker.io/library/python:latest...
Getting image source signatures
Copying blob e1aa7eb23da8 done   | 
Copying blob 7bb465c29149 done   | 
Copying blob 49b40be4436e done   | 
Copying blob 2b9b41aaa3c5 done   | 
Copying blob c558fac597f8 done   | 
Copying blob 11402150a57e done   | 
Copying blob 297428e82567 done   | 
Copying blob 28e810024ad5 done   | 
Copying config a3aef63c6c done   | 
Writing manifest to image destination
a3aef63c6c1029222ff635a72a0fcaddba1fd7a26abdf2491ace8eb3c654471e

查看镜像

[root@service ~]# podman images
REPOSITORY                TAG         IMAGE ID      CREATED      SIZE
docker.io/library/python  latest      a3aef63c6c10  4 weeks ago  1.04 GB

从容器文件创建容器镜像

[root@service ~]# vim Containerfile
FROM registry.access.redhat.com/ubi9/ubi:latest
RUN dnf install -y python39
CMD ["/bin/bash","-c","sleep infinity"]

[root@service ~]# podman build -t python39:1.0 .
STEP 1/3: FROM registry.access.redhat.com/ubi9/ubi:latest
Trying to pull registry.access.redhat.com/ubi9/ubi:latest...
Getting image source signatures
Checking if image destination supports signatures
Copying blob 1153e061da4e done   | 
Copying config 8d2a8803cf done   | 
Writing manifest to image destination
Storing signatures
STEP 2/3: RUN dnf install -y python39
Updating Subscription Management repositories.
Unable to read consumer identity
 
This system is not registered with an entitlement server. You can use subscription-manager to register.
 
Red Hat Universal Base Image 9 (RPMs) - BaseOS  118 kB/s | 515 kB     00:04    
Red Hat Universal Base Image 9 (RPMs) - AppStre 683 kB/s | 1.8 MB     00:02    
Red Hat Universal Base Image 9 (RPMs) - CodeRea  67 kB/s | 192 kB     00:02    
Package python3-3.9.18-1.el9_3.1.x86_64 is already installed.
Dependencies resolved.
Nothing to do.
Complete!
--> bf856a94a83f
STEP 3/3: CMD ["/bin/bash","-c","sleep infinity"]
COMMIT python39:1.0
--> 0274d417a217
Successfully tagged localhost/python39:1.0
0274d417a21704d9e66aec64b1a0f9934ae822e776704044523e12eb1db5063c

查看镜像

[root@service ~]# podman images
REPOSITORY                           TAG         IMAGE ID      CREATED        SIZE
localhost/python39                   1.0         0274d417a217  9 seconds ago  225 MB
registry.access.redhat.com/ubi9/ubi  latest      8d2a8803cfca  8 days ago     219 MB
docker.io/library/python             latest      a3aef63c6c10  4 weeks ago    1.04 GB

运行容器

[root@service ~]# podman create --name python39 localhost/python39:1.0 
2cf96e0ccbcbcceb66664cb5e93414e8f1f0163b44352c2f3b652ff2e95b9855
[root@service ~]# podman ps
CONTAINER ID  IMAGE       COMMAND     CREATED     STATUS      PORTS       NAMES
[root@service ~]# podman ps -a
CONTAINER ID  IMAGE                   COMMAND               CREATED        STATUS      PORTS       NAMES
2cf96e0ccbcb  localhost/python39:1.0  /bin/bash -c slee...  9 seconds ago  Created                 python39
[root@service ~]# podman start python39
python39
[root@service ~]# podman ps
CONTAINER ID  IMAGE                   COMMAND               CREATED         STATUS         PORTS       NAMES
2cf96e0ccbcb  localhost/python39:1.0  /bin/bash -c slee...  46 seconds ago  Up 17 seconds              python39

删除容器

[root@service ~]# podman stop python39
WARN[0010] StopSignal SIGTERM failed to stop container python39 in 10 seconds, resorting to SIGKILL 
python39
 
[root@service ~]# podman ps
CONTAINER ID  IMAGE       COMMAND     CREATED     STATUS      PORTS       NAMES
[root@service ~]# podman ps -a
CONTAINER ID  IMAGE                   COMMAND               CREATED        STATUS                       PORTS       NAMES
2cf96e0ccbcb  localhost/python39:1.0  /bin/bash -c slee...  2 minutes ago  Exited (137) 32 seconds ago              python39
 
[root@service ~]# podman rm python39
python39
[root@service ~]# podman rmi localhost/python39:1.0 
Untagged: localhost/python39:1.0
Deleted: 0274d417a21704d9e66aec64b1a0f9934ae822e776704044523e12eb1db5063c
Deleted: bf856a94a83f1f433aa54190152d11556e24bb105876eb8342947358a420b203