Host env. vars in Deployment (proxy)

[frankvdbh]

We have the requirement to use proxy servers for connecting various Edge devices.
The problem is that the proxy server is always different.

When a device is staged or first set-up, we can configure the device unique proxy settings in various places (docker runtime, edgeAgent container , .. following https://learn.microsoft.com/en-us/azure/iot-edge/how-to-configure-proxy-support?view=iotedge-1.5.)

However the problem is that we are not able to have dynamic proxy settings or variables inside a deployment:

Configure the edgeAgent module environment variables manually on the device itself, so that the IoT Edge agent can make the initial connection to IoT Hub. After the initial connection, you can configure the edgeAgent module remotely

Is there no possibility to take the proxy settings or environment variables from the host Edge device only ? We would now require unique deployments for each such device which is not possible given the deployment limits in Iot Hub.

[frankvdbh]

Similar Topic on Learn Q&A : https://learn.microsoft.com/en-us/answers/questions/2154202/iot-edge-variables-per-device-(proxy-setting)?comment=answer-1909937&page=1#comment-1894770

We configure variables in [agent.env] section of config.toml.
They are active when the edgeAgent container is first created.
As soon as the Iot Edge deployment is retrieved, the environment variables from config.toml are no longer in place. They are also not specified in the deployment manifest.
Is this by design or is there a way to always have merged set of variables from config.toml file and optionally override from deployment manifest?

[frankvdbh]

I implemented the following workaround:

• custom docker images based on the normal edgeAgent and edgeHub images.
• adding volume mapping for edgeAgent and edgeHub modules in the deployment manifest

The custom docker image has a wrapper entrypoint script that fetches the proxy setting from config file (visible via volume mapping) and then sets the https_proxy environment variable before starting the edgeAgent / edgeHub app.

This seems to work fine and allows me to use a same deployment manifest for all devices.

[yophilav]

@frankvdbh
Thank for the info! I have talked with my colleague. There isn't a default way to do what you're trying to do. The workaround solution you have is probably the cleanest way to do it.

Let me loop our PM to see how we should proceed.

[bishal41]

@frankvdbh: + 1 to what @yophilav said above... great that you are no longer are blocked and have a workaround. Do you have any other questions or suggestions? If not, we will proceed and close this issue. Thanks!