docker - 如何在 Rancher 中管理环境变量

Question

我想在堆栈中管理环境变量，然后服务可以使用它。例如：我定义了一个 evn tracker_ip=192.168.0.101，然后我想在服务创建中使用它。

我应该怎么办

Answer 1

There can be several answers depending on what you are trying to do and how you are deploying your stack.

Using the CLI / Rancher Compose

If you are using the command line, you can just use variable interpolation. Instructions on how to do so can be found in the official documentation:

https://docs.rancher.com/rancher/v1.5/en/cli/variable-interpolation/

Using the Rancher UI / Catalogs

If you want to do it through the Rancher UI, you can do it by creating a template in a catalog and having questions to input your environment variables. More details on how to do so here:

https://docs.rancher.com/rancher/v1.5/en/catalog/private-catalog/

You can define questions in the rancher-compose.yml file like this:

version: '2'
catalog:
  name: My Application
  version: v0.0.1
  questions:
  - variable: TRACKER_IP
    label: Tracker IP address
    required: true
    default: 192.168.0.101
    type: string

You can then push the answers to the environment section of your docker-compose.yml template for use within your image:

version: '2'
services:
  web:
    image: myimage
    ports:
    - 8000
    environment:
      TRACKER_IP: ${TRACKER_IP}

Answer 2

没有办法完全按照您的要求进行操作，因为这将允许编辑正在运行的容器的变量，并且容器是不可变的。环境变量可以在服务上定义，但不能在堆栈上定义一次并可供所有服务使用。

秘密有点像这样，可以跨服务共享，但不能编辑。

Answer 3

根据 tracker_ip 关联的位置，您还可以创建一个外部服务作为堆栈的一部分。外部服务本质上只是在 Rancher 中创建了一个 DNS 条目。因此，您可以将您的服务链接到 compose 中的 external_tracker 服务并参考tracker.

version: '2'
services:
  myservice:
    ...
    link:
      - tracker_service:tracker
...