Environment Variables in deployment.template.json

Expected Behavior

"modules": {
          "MODULE-NAME": {
            "version": "1.0",
            "type": "docker",
            "status": "running",
            "restartPolicy": "always",
            "env": {
              "VAR": {
                "value": "$VAR"
              },
              "VAR_ONE": {
                "value": "${VAR}"
              },
              "VAR_TWO": {
                "value": "$(VAR)"
              }
            },
            "settings": {
              "image": "some-image",
              "createOptions": {
                "Env": [
                  "VAR=$VAR",
                  "VAR_ONE=${VAR}",
                  "VAR_TWO=$(VAR)"
                ]
              }
            }
          }
        }

The expected behaviour is that the deployment template can pick environmental variables when they are requested from either the env for the iot module OR from Env in the create options for the docker container. However, neither of these options work.

Current Behavior

References to environment variables are treated as string values

Steps to Reproduce

Use the sample module template referenced in the Expected Behavior section

Context (Environment)

IoT Edge Simulator running on VSCode

Device (Host) Operating System

MacOSX

Container Operating System

node:lts-alpine

Runtime Versions

Version - 1.0.8.1.24554792

iotedged

Version - 1.0.8.1.24554792

Edge Agent

1.0.0

Edge Hub

1.0.0

[Gordonby]

Is there not a feature request here @arsing / @DoychinDoychev ?

I’m authoring a deployment.template.json file, and wanting to make use of variables in the .env file as described in this issue, and as already implemented for the CONTAINER_REGISTRY_USERNAME and CONTAINER_REGISTRY_PASSWORD variables in the .env file. The ability to make use of the existing templating build when “Generate IoT Edge Deployment Manifest” would be great, rather than the suggestion of using another templating engine for the new variables.

[heikki0]

@Gordonby, now when you mention feature requests, it would be helpful that one could use environment variables with some kind of simple logic so that one could at least combine strings, lets say VAR1=foo VAR2=bar and in the process of converting “${VAR1+VAR2}” from the template to the config file it would yield “foobar”. Similarly that many .js templates do.

Where one could discuss such a request? Thanks a lot with any guidance!