轻量级容器引擎iSula简介

墨蓝 2022-12-24 11:55 711阅读 0赞

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdW1pYW9jbg_size_16_color_FFFFFF_t_70_pic_center]  
iSula是一种生活在中南美洲亚马逊丛林的蚂蚁，被称为子弹蚁，据说被咬一口像被子弹打过一样疼，华为开源的容器引擎就使用这种强大的昆虫的名字，iSula是使用MuLan协议下使用C和C++开发的一种轻量级的容器，支持ARM和X86等体系架构，相较于Go语言实现的Docker的容器运行时，iSula的底层开销更小，是被设计用来在IOT等场景下的容器运行时。

# 基本信息 #

iSula的基本信息如下所示：

<table> 
 <thead> 
  <tr> 
   <th>项目</th> 
   <th>说明</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>使用说明</td> 
   <td><a href="https://openeuler.org/zh/docs/20.09/docs/Container/iSula%E5%AE%B9%E5%99%A8%E5%BC%95%E6%93%8E.html" rel="nofollow">iSula使用官方链接</a></td> 
  </tr> 
  <tr> 
   <td>开源/闭源</td> 
   <td>开源</td> 
  </tr> 
  <tr> 
   <td>开源协议</td> 
   <td>MulanPSL-2.0</td> 
  </tr> 
  <tr> 
   <td>开发语言</td> 
   <td>C/C++</td> 
  </tr> 
  <tr> 
   <td>代码管理地址</td> 
   <td>https://gitee.com/openeuler/iSulad</td> 
  </tr> 
  <tr> 
   <td>下载地址</td> 
   <td>https://gitee.com/openeuler/iSulad/releases</td> 
  </tr> 
  <tr> 
   <td>当前版本</td> 
   <td>2.0.7（2020/11/23）</td> 
  </tr> 
 </tbody> 
</table>

# iSula架构 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdW1pYW9jbg_size_16_color_FFFFFF_t_70_pic_center 1]  
从中可以看到这样几个特点：

*  对于HASEN的特定支持以及对于Kubernetes的CRI的通用性支持
 *  除了CLI还有GRPC和REST两种内部通信方式
 *  Engine中也是氛围Image管理和运行时管理，前者通过Content服务和Rootfs服务来完成后者通过Execution服务来支持
 *  服务的具体实现都是通过Plugin的模式来进行

# 事前准备 #

事前安装openEuler，本文以目前最新版本20.09为例进行说明

*  Linux内核版本

[root@liumiaocn ~]# uname -a
    Linux liumiaocn 4.19.140-2009.4.0.0048.oe1.x86_64 #1 SMP Thu Sep 24 09:39:46 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
    [root@liumiaocn ~]#

*  openEuler版本

[root@liumiaocn ~]# cat /etc/openEuler-release 
    openEuler release 20.09
    [root@liumiaocn ~]#

*  openEuler的简介与安装准备可参看：https://liumiaocn.blog.csdn.net/article/details/110255783

# 整体说明 #

> 今年openEuler峰会有个主题是“openEuler与centOS无关”，为什么有这个疑问，就是很多使用者可能会觉得好像再使用centOS的错觉，实际上Linux发行版大同小异，内核相同在此基础上开发者直接使用较多的往往是yum或者dnf这样包管理工具，而这些不同的发型版有的时候使用的都是相同的，比如systemd。而对于iSula，同样的主题可能是“iSula与docker无关”，抛开这个到底是什么，初学者或者初用者可以考虑两条基本原则：
> 
>  *  像使用centOS那样使用openEuler，碰到不一致的情况参看openEuler使用文档
>  *  像使用docker一样使用iSula，碰到不一致的情况参看iSula的使用文档

# 安装iSula #

这里直接使用OpenEuler提供的repo源进行安装，执行命令如下所示：

> 执行命令：yum install iSulad

[root@liumiaocn ~]# yum install iSulad
    OS                                                                                                      5.3 kB/s | 3.8 kB     00:00    
    everything                                                                                              5.7 kB/s | 3.8 kB     00:00    
    EPOL                                                                                                    4.5 kB/s | 2.9 kB     00:00    
    debuginfo                                                                                               5.8 kB/s | 3.8 kB     00:00    
    source                                                                                                  5.8 kB/s | 3.8 kB     00:00    
    Dependencies resolved.
    ========================================================================================================================================
     Package                          Architecture           Version                                               Repository          Size
    ========================================================================================================================================
    Installing:
     iSulad                           x86_64                 2.0.5-20200923.100811.git275398ce.oe1                 OS                 2.6 M
    Installing dependencies:
     c-ares                           x86_64                 1.16.1-1.oe1                                          OS                  96 k
     clibcni                          x86_64                 2.0.3-20200904.104745.git413e6757.oe1                 OS                  37 k
     emacs-filesystem                 noarch                 1:26.3-1.oe1                                          OS                 8.0 k
     gflags                           x86_64                 2.2.2-1.oe1                                           OS                  95 k
     gperftools-libs                  x86_64                 2.8-2.oe1                                             OS                 271 k
     gpm-libs                         x86_64                 1.20.7-21.oe1                                         OS                  18 k
     grpc                             x86_64                 1.30.2-1.oe1                                          OS                 5.6 M
     http-parser                      x86_64                 2.9.4-1.oe1                                           OS                  30 k
     lcr                              x86_64                 2.0.3-20200904.101728.git8b4641a4.oe1                 OS                 312 k
     libunwind                        x86_64                 1.4.0-1.oe1                                           OS                  55 k
     libwebsockets                    x86_64                 4.0.20-2.oe1                                          OS                 217 k
     lxc                              x86_64                 4.0.3-2020092501.oe1                                  OS                 179 k
     lxc-libs                         x86_64                 4.0.3-2020092501.oe1                                  OS                 411 k
     protobuf                         x86_64                 3.12.3-14.oe1                                         OS                 951 k
     protobuf-devel                   x86_64                 3.12.3-14.oe1                                         OS                 3.3 M
     rsync                            x86_64                 3.2.1-1.oe1                                           OS                 289 k
     vim-common                       x86_64                 2:8.2-4.oe1                                           OS                 6.8 M
     vim-enhanced                     x86_64                 2:8.2-4.oe1                                           OS                 1.4 M
     vim-filesystem                   noarch                 2:8.2-4.oe1                                           OS                  10 k
     yajl                             x86_64                 2.1.0-12.oe1                                          OS                  34 k
     zlib-devel                       x86_64                 1.2.11-17.oe1                                         OS                  90 k
    
    Transaction Summary
    ========================================================================================================================================
    Install  22 Packages
    
    Total download size: 23 M
    Installed size: 99 M
    Is this ok [y/N]: y
    ...省略

和docker缺省的安装相比，确实会发现明显少很多依赖

# 启动iSula #

> 执行命令：systemd start isulad

# 查看iSula #

> 执行命令：systemd status isulad

[root@liumiaocn ~]# systemctl status isulad
    ● isulad.service - iSulad Application Container Engine
         Loaded: loaded (/usr/lib/systemd/system/isulad.service; enabled; vendor preset: disabled)
         Active: active (running) since Tue 2020-12-01 06:35:31 CST; 11min ago
       Main PID: 1275 (isulad)
          Tasks: 13 (limit: 12523)
         Memory: 21.4M
         CGroup: /system.slice/isulad.service
                 └─1275 /usr/bin/isulad
    
    12月 01 06:35:30 liumiaocn systemd[1]: Starting iSulad Application Container Engine...
    12月 01 06:35:31 liumiaocn systemd[1]: Started iSulad Application Container Engine.
    [root@liumiaocn ~]#

可以看到此进程的父进程为1号进程

[root@liumiaocn ~]# ps -ef |grep 1275 |grep -v grep
    root        1275       1  0 06:35 ?        00:00:00 /usr/bin/isulad
    [root@liumiaocn ~]#

1号进程的详细信息如下

[root@liumiaocn ~]# ps -ef |grep -w systemd |grep -v grep
    root           1       0  0 06:35 ?        00:00:01 /usr/lib/systemd/systemd --switched-root --system --deserialize 16
    root         547       1  0 06:35 ?        00:00:00 /usr/lib/systemd/systemd-journald
    root         568       1  0 06:35 ?        00:00:00 /usr/lib/systemd/systemd-udevd
    dbus        1079       1  0 06:35 ?        00:00:00 /usr/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation --syslog-only
    root        1086       1  0 06:35 ?        00:00:00 /usr/lib/systemd/systemd-logind
    systemd+    1249       1  0 06:35 ?        00:00:00 /usr/lib/systemd/systemd-networkd
    root        1608       1  0 06:35 ?        00:00:00 /usr/lib/systemd/systemd-userdbd
    root        1613       1  0 06:35 ?        00:00:00 /usr/lib/systemd/systemd --user
    root        1698    1608  0 06:45 ?        00:00:00 systemd-userwork
    root        1699    1608  0 06:45 ?        00:00:00 systemd-userwork
    root        1700    1608  0 06:45 ?        00:00:00 systemd-userwork
    [root@liumiaocn ~]#

虽然说openEuler和centOS无关，从这个角度说，systemd也与Linux发行版无关，这些无论是哪个发行版，使用起来都是一样的，只要使用的是systemd而不是init.d。

# 版本确认 #

前面说过，虽然不懂iSula，但是还是了解docker的，虽然iSula和docker无关，但是可以考虑像使用docker那样大体的来使用iSula，比如进行版本确认

[root@liumiaocn ~]# isula version
    Client:
      Version:	2.0.5
      Git commit:	f84000843bf2ba98adea547721b235e3b77168e1
      Built:	2020-09-27T17:45:13.009126010+00:00
    
    Server:
      Version:	2.0.5
      Git commit:	f84000843bf2ba98adea547721b235e3b77168e1
      Built:	2020-09-27T17:45:13.009126010+00:00
    
    OCI config:
      Version:	1.0.1
      Default file:	/etc/default/isulad/config.json
    
    [root@liumiaocn ~]#

# 镜像操作 #

*  确认当前镜像

[root@liumiaocn ~]# isula images
    REPOSITORY                     TAG        IMAGE ID             CREATED              SIZE       
    [root@liumiaocn ~]#

*  拉取nginx镜像

[root@liumiaocn ~]# isula pull nginx
    Image "nginx" pulling
    Failed to pull image nginx with error: Invalid image name, no host found
    [root@liumiaocn ~]#

# 配置文件 #

可以看到上述镜像拉取操作中出现了错误，

*  错误原因：提示其实不清晰，是需要设定私库或者docker的官方库，安装之后需要手动设定。
 *  iSula配置文件：/etc/isulad/daemon.json
 *  缺省配置：

[root@liumiaocn ~]# cat /etc/isulad/daemon.json 
    { 
        "group": "isulad",
        "default-runtime": "lcr",
        "graph": "/var/lib/isulad",
        "state": "/var/run/isulad",
        "engine": "lcr",
        "log-level": "ERROR",
        "pidfile": "/var/run/isulad.pid",
        "log-opts": { 
            "log-file-mode": "0600",
            "log-path": "/var/lib/isulad",
            "max-file": "1",
            "max-size": "30KB"
        },
        "log-driver": "stdout",
        "hook-spec": "/etc/default/isulad/hooks/default.json",
        "start-timeout": "2m",
        "storage-driver": "overlay2",
        "storage-opts": [
            "overlay2.override_kernel_check=true"
        ],
        "registry-mirrors": [
        ],
        "insecure-registries": [
        ],
        "pod-sandbox-image": "",
        "native.umask": "secure",
        "network-plugin": "",
        "cni-bin-dir": "",
        "cni-conf-dir": "",
        "image-layer-check": false,
        "use-decrypted-key": true,
        "insecure-skip-verify-enforce": false
    }
    [root@liumiaocn ~]#

*  对应方法：设定上述json中的registry-mirrors即可，比如修改内容如下

"registry-mirrors": [
            "docker.io"
        ],

然后重启iSula服务，即可拉取镜像了

[root@liumiaocn ~]# systemctl restart isulad
    [root@liumiaocn ~]# isula pull nginx
    Image "nginx" pulling
    Image "bc9a0695f5712dcaaa09a5adc415a3936ccba13fc2587dfd76b1b8aeea3f221c" pulled
    [root@liumiaocn ~]# isula images
    REPOSITORY                     TAG        IMAGE ID             CREATED              SIZE       
    nginx                          latest     bc9a0695f571         2020-11-25 08:30:19  126.716 MB 
    [root@liumiaocn ~]#

# 运行服务 #

*  没有-p选项映射端口

[root@liumiaocn ~]# isula run -p 80:80 nginx
    Unkown flag found:'p'
    [root@liumiaocn ~]#

*  普通方式启动

[root@liumiaocn ~]# isula run -d --name nginx nginx
    71e54ad3cd8f5f3899caef06856cac9aa2139bdc81e20264e3de7f9e14f253c6
    [root@liumiaocn ~]#

*  容器确认

[root@liumiaocn ~]# isula ps
    CONTAINER ID	IMAGE	COMMAND               	CREATED      	STATUS      	PORTS	NAMES
    71e54ad3cd8f	nginx	"/docker-entrypoin..." 	3 seconds ago	Up 3 seconds	     	nginx
    [root@liumiaocn ~]#

*  进入容器确认

[root@liumiaocn ~]# isula exec -it nginx sh
    # which curl
    /usr/bin/curl
    # curl localhost
    <!DOCTYPE html>
    <html>
    <head>
    <title>Welcome to nginx!</title>
    <style>
        body {
            width: 35em;
            margin: 0 auto;
            font-family: Tahoma, Verdana, Arial, sans-serif;
        }
    </style>
    </head>
    <body>
    <h1>Welcome to nginx!</h1>
    <p>If you see this page, the nginx web server is successfully installed and
    working. Further configuration is required.</p>
    
    <p>For online documentation and support please refer to
    <a href="http://nginx.org/">nginx.org</a>.<br/>
    Commercial support is available at
    <a href="http://nginx.com/">nginx.com</a>.</p>
    
    <p><em>Thank you for using nginx.</em></p>
    </body>
    </html>
    #

可以看到nginx容器已经正常运行了

# 参考内容 #

https://openeuler.org/zh/docs/20.09/docs/Container/iSula%E5%AE%B9%E5%99%A8%E5%BC%95%E6%93%8E.html

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