template.json

{
    "parameters": {
        "name": {
            "type": "string"
        },
        "dockerRegistryImageName": {
            "type": "string"
        },
        "hostingPlanName": {
            "type": "string"
        },
        "hostingEnvironment": {
            "type": "string"
        },
        "location": {
            "type": "string"
        },
        "sku": {
            "type": "string"
        },
        "skuCode": {
            "type": "string"
        },
        "workerSize": {
            "type": "string"
        },
        "serverFarmResourceGroup": {
            "type": "string"
        },
        "subscriptionId": {
            "type": "string"
        }
    },
    "resources": [
        {
            "apiVersion": "2016-03-01",
            "name": "[parameters('name')]",
            "type": "Microsoft.Web/sites",
            "properties": {
                "name": "[parameters('name')]",
                "siteConfig": {
                    "appSettings": [
                        {
                            "name": "DOCKER_CUSTOM_IMAGE_NAME",
                            "value": "[parameters('dockerRegistryImageName')]"
                        }
                    ],
                    "appCommandLine": "",
                    "linuxFxVersion": "DOCKER|kapilthakkar/azure-rails"
                },
                "serverFarmId": "[concat('/subscriptions/', parameters('subscriptionId'),'/resourcegroups/', parameters('serverFarmResourceGroup'), '/providers/Microsoft.Web/serverfarms/', parameters('hostingPlanName'))]",
                "hostingEnvironment": "[parameters('hostingEnvironment')]"
            },
            "location": "[parameters('location')]",
            "tags": {
                "[concat('hidden-related:', '/subscriptions/', parameters('subscriptionId'),'/resourcegroups/', parameters('serverFarmResourceGroup'), '/providers/Microsoft.Web/serverfarms/', parameters('hostingPlanName'))]": "empty"
            },
            "dependsOn": [
                "[concat('Microsoft.Web/serverfarms/', parameters('hostingPlanName'))]"
            ]
        },
        {
            "apiVersion": "2016-09-01",
            "name": "[parameters('hostingPlanName')]",
            "type": "Microsoft.Web/serverfarms",
            "location": "[parameters('location')]",
            "properties": {
                "name": "[parameters('hostingPlanName')]",
                "workerSizeId": "[parameters('workerSize')]",
                "reserved": true,
                "numberOfWorkers": "1",
                "hostingEnvironment": "[parameters('hostingEnvironment')]"
            },
            "sku": {
                "Tier": "[parameters('sku')]",
                "Name": "[parameters('skuCode')]"
            },
            "kind": "linux"
        }
    ],
    "$schema": "http://schema.management.azure.com/schemas/2014-04-01-preview/deploymentTemplate.json#",
    "contentVersion": "1.0.0.0"
}