使用 S2I 构建云原生应用

云计算 2023-01-04 LOVEHL^ˇ^ 手机阅读

1. S2I 能解决什么问题

上图是 S2I 的工作流，S2I CLI 依赖于 Docker 环境。主要分为两步：

  • 通过 BASE IMAGE 、S2I Scripts 构建应用的基础镜像

  • 将源码移动到应用的基础镜像，仅添加一层文件，得到最终的镜像文件
  • 打补丁，如果所依赖的镜像需要安全补丁，S2I 允许你一次性重新构建所有镜像。
  • 高效，在构建过程中，S2I 不允许运行任意的 yum install 命令，以防止降低开发迭代速度
  • 生态，S2I 鼓励一个共享镜像生态。从而你的应用可以实现最佳实践。
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    pip install django==1.11
django-admin startproject django_example
echo django==1.11 > ./django_example/requirements.txt
tree -L 3
.
└── django_example
    ├── django_example
    │   ├── __init__.py
    │   ├── settings.py
    │   ├── urls.py
    │   └── wsgi.py
    ├── manage.py
    └── requirements.txt
    • 查看镜像
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    docker images
REPOSITORY                 TAG                 IMAGE ID            CREATED             SIZE
hello-django               latest              042c6143ecf9        50 seconds ago      669MB
    • 运行应用
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    docker run -p 8080:8080 hello-django
---> Migrating database ...
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, sessions
Running migrations:
  Applying contenttypes.0001_initial... OK
  Applying auth.0001_initial... OK
  Applying admin.0001_initial... OK
  Applying admin.0002_logentry_remove_auto_add... OK
  Applying contenttypes.0002_remove_content_type_name... OK
  Applying auth.0002_alter_permission_name_max_length... OK
  Applying auth.0003_alter_user_email_max_length... OK
  Applying auth.0004_alter_user_username_opts... OK
  Applying auth.0005_alter_user_last_login_null... OK
  Applying auth.0006_require_contenttypes_0002... OK
  Applying auth.0007_alter_validators_add_error_messages... OK
  Applying auth.0008_alter_user_username_max_length... OK
  Applying sessions.0001_initial... OK
---> Serving application with 'manage.py runserver' ...
WARNING: this is NOT a recommended way to run you application in production!
Consider using gunicorn or some other production web server.
Performing system checks...
System check identified no issues (0 silenced).
August 26, 2019 - 08:08:36
Django version 1.11, using settings 'django_example.settings'
Starting development server at http://0.0.0.0:8080/
Quit the server with CONTROL-C.
    • 查看应用

    5. 参考

    • https://github.com/openshift/source-to-image
    • https://github.com/sclorg/s2i-python-container
    • https://www.openshift.com/blog/create-s2i-builder-image