deploy multiple vm using loop

main.bicep

param vmPrefix string
param location string
param vmCount int

module vm 'vm.bicep' = [for i in range(0, vmCount): {
  name: 'vm-${i}'
  params:{
    name: '${vmPrefix}-${substring(uniqueString(resourceGroup().id), 0, 5)}-${i}'
    location: location
    vnetName:vnet.name
    subnetName: 'subnet1'
  }
}]

resource vnet 'Microsoft.Network/virtualNetworks@2019-11-01' = {
  name: 'name'
  location: resourceGroup().location
  properties: {
    addressSpace: {
      addressPrefixes: [
        '10.0.0.0/16'
      ]
    }
    subnets: [
      {
        name: 'subnet1'
        properties: {
          addressPrefix: '10.0.0.0/24'
        }
      }
    ]
  }
}

main.json

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "metadata": {
    "_generator": {
      "name": "bicep",
      "version": "0.3.539.46024",
      "templateHash": "12748056562629077740"
    }
  },
  "parameters": {
    "vmPrefix": {
      "type": "string"
    },
    "location": {
      "type": "string"
    },
    "vmCount": {
      "type": "int"
    }
  },
  "functions": [],
  "resources": [
    {
      "type": "Microsoft.Network/virtualNetworks",
      "apiVersion": "2019-11-01",
      "name": "name",
      "location": "[resourceGroup().location]",
      "properties": {
        "addressSpace": {
          "addressPrefixes": [
            "10.0.0.0/16"
          ]
        },
        "subnets": [
          {
            "name": "subnet1",
            "properties": {
              "addressPrefix": "10.0.0.0/24"
            }
          }
        ]
      }
    },
    {
      "copy": {
        "name": "vm",
        "count": "[length(range(0, parameters('vmCount')))]"
      },
      "type": "Microsoft.Resources/deployments",
      "apiVersion": "2019-10-01",
      "name": "[format('vm-{0}', range(0, parameters('vmCount'))[copyIndex()])]",
      "properties": {
        "expressionEvaluationOptions": {
          "scope": "inner"
        },
        "mode": "Incremental",
        "parameters": {
          "name": {
            "value": "[format('{0}-{1}-{2}', parameters('vmPrefix'), substring(uniqueString(resourceGroup().id), 0, 5), range(0, parameters('vmCount'))[copyIndex()])]"
          },
          "location": {
            "value": "[parameters('location')]"
          },
          "vnetName": {
            "value": "name"
          },
          "subnetName": {
            "value": "subnet1"
          }
        },
        "template": {
          "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
          "contentVersion": "1.0.0.0",
          "metadata": {
            "_generator": {
              "name": "bicep",
              "version": "0.3.539.46024",
              "templateHash": "18020905035165685897"
            }
          },
          "parameters": {
            "name": {
              "type": "string"
            },
            "location": {
              "type": "string"
            },
            "vnetName": {
              "type": "string"
            },
            "subnetName": {
              "type": "string"
            }
          },
          "functions": [],
          "resources": [
            {
              "type": "Microsoft.Network/networkInterfaces",
              "apiVersion": "2020-11-01",
              "name": "@{name}-nic",
              "location": "[parameters('location')]",
              "properties": {
                "ipConfigurations": [
                  {
                    "name": "ipconfig1",
                    "properties": {
                      "privateIPAllocationMethod": "Dynamic",
                      "subnet": {
                        "id": "[resourceId('Microsoft.Network/virtualNetworks/subnets', parameters('vnetName'), parameters('subnetName'))]"
                      }
                    }
                  }
                ]
              }
            },
            {
              "type": "Microsoft.Compute/virtualMachines",
              "apiVersion": "2020-12-01",
              "name": "[parameters('name')]",
              "location": "[parameters('location')]",
              "properties": {
                "networkProfile": {
                  "networkInterfaces": [
                    {
                      "id": "[resourceId('Microsoft.Network/networkInterfaces', '@{name}-nic')]"
                    }
                  ]
                }
              },
              "dependsOn": [
                "[resourceId('Microsoft.Network/networkInterfaces', '@{name}-nic')]"
              ]
            }
          ]
        }
      },
      "dependsOn": [
        "[resourceId('Microsoft.Network/virtualNetworks', 'name')]"
      ]
    }
  ]
}

vm.bicep

param name string
param location string
param vnetName string
param subnetName string

resource vnet 'Microsoft.Network/virtualNetworks@2019-11-01' existing = {
  name: vnetName
}

resource subnet 'Microsoft.Network/virtualNetworks/subnets@2020-11-01' existing = {
  parent: vnet
  name: subnetName
}

resource nic 'Microsoft.Network/networkInterfaces@2020-11-01' = {
  name: '@{name}-nic'
  location: location
  properties: {
    ipConfigurations: [
      {
        name: 'ipconfig1'
        properties: {
          privateIPAllocationMethod: 'Dynamic'
          subnet: {
            id: subnet.id
          }
        }
      }
    ]
  }
}

resource virtualMachine 'Microsoft.Compute/virtualMachines@2020-12-01' = {
  name: name
  location: location
  properties: {
    networkProfile: {
      networkInterfaces: [
        {
          id: nic.id
        }
      ]
    }
  }
}