[Issue] Unclear how to provide array as a parameter

[wasker]

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Output from azd version
Run azd version and copy and paste the output here: azd version 1.19.0 (commit b3d68ce)

Describe the bug

Bicep supports array as a type of parameter, however, it's unclear how to define that in the parameters file and azd env set.

Expected behavior

Documentation to show how array type is handled by azd.

[Menghua1]

@wasker Bicep supports multiple array types. Here's how to define them:

Type	main.bicep	main.parameters.json	azd env set
string[]	param regions string[] = ["eastus", "westus"]	"regions": { "value": ["eastus", "westus"] }	azd env set REGIONS '["eastus","westus"]'
int[]	param ports int[] = [80, 443]	"ports": { "value": [80, 443] }	azd env set PORTS '[80,443]'
bool[]	param flags bool[] = [true, false]	"flags": { "value": [true, false] }	azd env set FLAGS '[true,false]'
object[]	param configs object[] = [{"name":"dev"}]	"configs": { "value": [{"name":"dev"}] }	azd env set CONFIGS '[{"name":"dev"}]'
array	param items array = ["a", 1, true]	"items": { "value": ["a", 1, true] }	azd env set ITEMS '["a",1,true]'

Note: string[], int[], bool[], object[] enforce element types at compile time; array allows mixed types.

More documentation can be found at: https://learn.microsoft.com/en-us/azure/azure-resource-manager/bicep/data-types#arrays.

Cc: @rajeshkamal5050

[wasker]

/unresolve

[wasker]

Did you verify the recommendation?

How would azd env set REGIONS translate into a change for main.parameters.json?

On the screenshot below you can see that e.g., environmentName is set to "value": "${AZURE_ENV_NAME}". From your recommendation REGIONS is supposed to somehow replace "regions" value in the JSON file, but there's no variable placeholder in the suggested value. The documentation doesn't describe how the placeholder should look like in case of an array.

I could've gotten this suggestion from "AI" myself.

[vhvb1989]

@wasker , have you tried running the suggested:

azd env set REGIONS '["eastus","westus"]'

Then map the env var to a param in param.json like

"regions": {
   "value": "${REGIONS}"
}

During runtime, azd should replace ${REGIONS} for '["eastus","westus"]' and use it as input param.

Would that help?

[wasker]

I did. Did you?

main.parameters.json:

{
    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentParameters.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
      "environmentName": {
        "value": "${AZURE_ENV_NAME}"
      },
      "location": {
        "value": "${AZURE_LOCATION}"
      },
      "regions": {
        "value": "${REGIONS}"
      }
    }
}

Take 1:

azd env set REGIONS '["eastus","westus"]'

azd provision --preview --debug

ERROR: initializing provisioning manager: resolving bicep parameters file: error unmarshalling Bicep template parameters: invalid character 'e' after object key:value pair

Take 2:

azd env set REGIONS "['eastus','westus']"

azd provision --preview --debug

ERROR: deployment failed: error deploying infrastructure: generating preview: error code: InvalidTemplate, message: Deployment template validation failed: 'The provided value for the template parameter 'regions' is not valid. Expected a value of type 'Array', but received a value of type 'String'. Please see https://aka.ms/arm-create-parameter-file for usage details.'..

[wasker]

For take 3 I updated main.parameters.json to look like so:

{
    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentParameters.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
      "environmentName": {
        "value": "${AZURE_ENV_NAME}"
      },
      "location": {
        "value": "${AZURE_LOCATION}"
      },
      "regions": {
        "value": ${REGIONS}
      }
    }
}

(This makes it invalid JSON right away.)

Take 3:

azd env set REGIONS "['eastus','westus']"

azd provision --preview --debug

ERROR: initializing provisioning manager: resolving bicep parameters file: error unmarshalling Bicep template parameters: invalid character '$' looking for beginning of value

[vhvb1989]

@wasker, there is a limitation for azd parsing the value from the terminal. Everything that is not a number is converted to string.
There are 2 workarounds you can try:

Manually edit the .env file with an array like

regions=["eastus","westus"]

You can run a bash or pwsh script to write this line to the .env to workaround the current limitation in azd.

use the env.config approach.
When using the environment config you don't need to create a mapping, you just need to directly use the name of the parameter.
So you can run

azd env config set infra.parameters.regions ["someStringValue","otherValue"]

This writes a node regions in config.json , next to the .env file and is it automatically used before looking at parameter's mapping. Which means that if you also have a mapping for the parameter to another ENV VAR, it is not used.
This config is used to persist selections you do then azd prompts for a value. Since it is JSON, it can handle array and object better than .env

Let me know how it goes.

[wasker]

How the placeholder is set up?

If it's still like so

{
    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentParameters.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
      "environmentName": {
        "value": "${AZURE_ENV_NAME}"
      },
      "location": {
        "value": "${AZURE_LOCATION}"
      },
      "regions": {
        "value": "${REGIONS}"
      }
    }
}

Then result for manual .env edit is still the "Expected a value of type 'Array', but received a value of type 'String'" error.

The azd env config set way keeps using default value specified in the bicep file whether the JSON file has the placeholder or not.