Set an appsetting value conditionally in an ARM template

Question

We have an Azure ARM template, which is adding appsettings for a Microsoft.Web/site.

"resources": [
    {
        "apiVersion": "2016-03-01",
        "name": "myazurefunction", 
        "type": "Microsoft.Web/sites", 
        "properties": {
            "name": "myazurefunction", 
            "siteConfig": {
                "appSettings": [
{
    "name": "MY_SERVICE_URL", 
    "value": "[concat('https://myservice-', parameters('env'), '.domain.ca')]"
}
                ]    
            }
        }
    }
]

We also have four parameters.environment.json files. For instance, this is the content of parameters.dev.json.

{
    "$schema": "https://schema.management.azure.com/schemas/2015-01-01...",
    "contentVersion": "1.0.0.0",
    "parameters": {
        "env": {
            "value": "dev"
        }
    }
}

The template and its parameters favor convention over configuration. This is working nicely for the most part, and leads to the following MY_SERVICE_URL values.

The problem is that we want to break the convention for the dev environment. That is, we want it to have a MY_SERVICE_URL that looks something like this:

https://abc123.foo.bar.baz.ca

How can we configure the ARM template to break the convention for only one environment?

My first though is to use a conditional like this, but such an ARM function appears not to be available.

"name": "MY_SERVICE_URL", 
"value": "[parameters('env') -eq 'dev' 
    ? 'https://abc123.foo.bar.baz.ca' 
    :  concat('https://myservice-', parameters('env'), '.domain.ca')]"

4c74356b41 · Accepted Answer · 2017-03-08 17:52:23Z

2

just create a variable that would depend on the parameter:

"parameters": {
...
"DeploymentType": {
    "type": "string",
    "allowedValues": [
        "Dev",
        "Prod"
    ]
}
...
"variables": {
    "Dev": "https://some_service-ci.domain.com",
    "Prod": "https://abc123.foo.bar.baz.com",
    "DeploymentVariable": "[variables(parameters('DeploymentType'))]",
...
"appSettings": [
    "name": "MY_SERVICE_URL", 
    "value": "[variables('DeploymentVariable')]"
]
...

Ok, so how does this work. you pass in the parameter 'DeploymentType', it can be PROD or DEV. If you pass DEV "DeploymentVariable": "[variables(parameters('DeploymentType'))]", - this evaluates to "[variables('Dev')]" and gets the value of "Dev": "https://some_service-ci.domain.com",

edited Mar 8, 2017 at 17:52

answered Mar 8, 2017 at 17:39

4c74356b41

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1 Comment

4c74356b41 Over a year ago

sorry, fixed a typo and added comment @ShaunLuttin

Shaun Luttin · Accepted Answer · 2017-03-08 18:35:43Z

0

For the example in the question, the answer ended up looking like this:

"variables": {
   "myServiceUrl_default": "[concat('https://myservice-', parameters('env'), '.domain.ca')]",
   "myServiceUrl_dev": "https://abc123.foo.bar.baz.ca",
   "myServiceUrl_ci": "[variables('myServiceUrl_default')]",
   "myServiceUrl_qa": "[variables('myServiceUrl_default')]",
   "myServiceUrl_prod": "[variables('myServiceUrl_default')]",
   "myServiceUrl": "[variables(concat('myServiceUrl_', 'parameters('env')'))]"  
},

...

"appSettings: [
   {
      "name": "MY_SERVICE_URL",
      "value": "[variables('myServiceUrl')]"
   }
]

answered Mar 8, 2017 at 18:35

Shaun Luttin

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