Overview

The below steps will deployment an Azure environment using a Virtual Network for hosting a private virtual machine and using a VPN Gateway to create a secure private environment for development where developers can use dev containers on VS Code.

Prerequisites

• Azure Subscription for hosting the dev container hosts.
• VS Code
• VS Code Extensions able to be installed on the developer desktop and dev container host.
• Access to setup ssh-agent on developer desktop/laptop
• Azure cli and bicep installed

Scenarios

A number of different infrastructure scenarios are supported, which enable this repository to support both simple and more secure configurations.

Scenario	Description	Status
Public	A simple "over the internet" scenario which is great for rapid development by a single developer	In QA (wip)
P2S VPN	Designed for a single developer to use. Leveraging a P2S VPN and DNS resolution via Azure DNS Resolver	Needs refactoring
Landing Zone	A scaled developer environment that can be joined to the Hub Virtual Network from an Azure Landing Zone implementation	Not started

Public Scenario

For simple, cost optimised scenarios the Virtual Machine powering the Dev Container experience can be exposed to the internet directly. An SSH key pair is used to secure access, and a Just In Time rule can be leveraged in the subnet Network Security Group to restrict access to just the calling IP address.

Deploy the Azure Infrastructure

With Bash

rg=YourResourceGroup
deployingUser=$(az ad signed-in-user show --query id --out tsv)
az deployment group create -n devcontdemo -g $RG -f .\deploy\main.bicep -p resourceName=devcontdemo deployingUserPrincipalId=$deployingUser exposureModel=publicIpOnVm
kvName=az deployment group show -n devcontdemo -g $RG --query properties.outputs.keyVaultName.value -o tsv
az keyvault secret show --vault-name $kvName -n vmSshPrivate --query value -o tsv

With PowerShell

$rg=YourResourceGroup
$deployingUser=az ad signed-in-user show --query id --out tsv
$clientPublicIp=(Invoke-WebRequest -uri "https://api.ipify.org/").Content

az deployment group create -n devcontdemo -g $RG -f .\deploy\main.bicep -p resourceName=devcontdemo deployingUserPrincipalId=$deployingUser exposureModel=publicIpOnVm clientOutboundIpAddress=clientPublicIp
$kvName=az deployment group show -n devcontdemo -g $RG --query properties.outputs.keyVaultName.value -o tsv
$sshKey=az keyvault secret show --vault-name $kvName -n vmSshPrivate --query value -o tsv

Local workstation configuration

cd $env:userprofile
mkdir .ssh -ErrorAction SilentlyContinue
$sshKey | out-file "devmac1.pub" 
start-service ssh-agent
ssh-add "$env:userprofile\.ssh\devmac1.pub"
Test-NetConnection <VM DNS Address> -Port 22

Private Scenario : Point to Site

todo

TO TIDY UP

Client

Key to start with the client side as from here a few key dependent items will need to be created prior to deploying the Azure Services.

• Install VS Code

• Install the Remote Development extension:
  

• Creates a ssh key pair for connecting to the VM via VS Code

  • From Windows: https://docs.microsoft.com/azure/virtual-machines/linux/ssh-from-windows

  • From Linux/Mac: https://docs.microsoft.com/azure/virtual-machines/linux/mac-create-ssh-keys

  • Example:

      ssh-keygen -m PEM -t rsa -b 4096

• Copy the private ssh key into .ssh folder

• Store both keys in a secure location for possible future use. The Public key will be used in a later step.

• Setup the SSH Agent for VSCode to use the key for SSH Remoting to the Virtual Machine using PowerShell.

    set-service ssh-agent -startuptype "Automatic"
    start-service ssh-agent
    ssh-add C:\Users\<user>\.ssh\<keyname>

  If errors connecting to the DevContainer (e.g. Crypto Errors) Upgrade the ssh agent. The following Powershell with find the latest zip file links:

    [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
    $url = 'https://github.com/PowerShell/Win32-OpenSSH/releases/latest/'
    $request = [System.Net.WebRequest]::Create($url)
    $request.AllowAutoRedirect=$false
    $response=$request.GetResponse()
    $([String]$response.GetResponseHeader("Location")).Replace('tag','download') + '/OpenSSH-Win64.zip'  
    $([String]$response.GetResponseHeader("Location")).Replace('tag','download') + '/OpenSSH-Win32.zip'

• Optional: Install Docker Extension for visibility of the containers and images created
  

Generate Certificate (Self-Signed) for connecting to VPN Gateway

This following process shows how to generate root and client certificates from a Windows machine using PowerShell. This is key to securely connect to the VPN Gateway from the client machine. The benefit is that the client machine will be directly connected into the VNET that's created later. Thus, no need for Bastion or public IP Addresses for using the development Virtual Machine

• Create certificates:

$rootcert = New-SelfSignedCertificate -Type Custom ` -Subject "CN=P2SROOT" ` -KeyExportPolicy Exportable ` -KeySpec Signature ` -HashAlgorithm sha256 ` -KeyLength 2048 ` -CertStoreLocation "Cert:\CurrentUser\My" ` -KeyUsageProperty Sign ` -KeyUsage CertSign

New-SelfSignedCertificate -Type Custom ` -DnsName P2SCLIENT ` -KeySpec Signature ` -Subject "CN=P2SCLIENT" ` -KeyExportPolicy Exportable ` -HashAlgorithm sha256 ` -KeyLength 2048 ` -CertStoreLocation "Cert:\CurrentUser\My" ` -Signer $rootcert ` -TextExtension @("2.5.29.37={text}1.3.6.1.5.5.7.3.2")

• Export certificates:
  • Run commannd MMC to open the Microsoft Management Console.
  • Goto File/Add or Remove Snap-ins
  • Double click on Certificates and select My user account
  • Click OK
  • Goto Personal/Certificates
  • Export the root certificate
    • Do not export the private key
    • Select Base 64 encoded X.509 (.CER)
  • Export the client certificate
    • Yes, export the private key
    • Make sure Personal Information Exchange - PKCS #12 (.PFX) is selected
    • Enter password for securing the private certificate
  • Store both certificates in a safe place for use later in the process

The root certificate will be used to configure the P2S VPN Gateway
The client certificate will need to be installed in the client machine.

Deploy Azure services including Virtual Machine

This will get the configuration in-place for deploying the Azure services.

Below shows the architecture:

Azure Private DNS Resolver is currently in Preview

• The following needs to be added to KeyVault as secrets, as they're used during the deployment process:

  • SSH Public Key
  • Public Root Certificate

    • Remove the -----BEGIN CERTIFICATE----- and -----END CERTIFICATE-----

• The Bicep parameters file needs to be updated for deployment. Here's a link to an example: template.parameters.json

• Sections in file (Key to update "<...>" values ) :

  • General

  "resourceGroupName": {
      "value": "<Resource Group Name>"
    },
    "secretsKeyVault": {
      "value": {
        "kvName": "<Name of KeyVault>",
        "resourceGroup": "<Resource Group Name for KeyVault>"
      }
    },
    "namingConvension": {
      "value": {
        "environment": "<environment for naming e.g. prod>",
        "application": "<name of application e.g. vscode>"
      }
    },
    "location": {
      "value": "<location e.g. uksouth>"
    },

  • Networking

      "vnet_object": {
      "value": {
          "addressPrefix": "10.2.0.0/25",
          "subnets" : [
            {
              "name": "GatewaySubnet",
              "addressSpace": "10.2.0.0/29",
              "specialSubnet": true,
              "securityRules": [],
              "delegations": []
            },
            {
              "name": "dnsresolver",
              "addressSpace": "10.2.0.16/28",
              "specialSubnet": false,
              "securityRules": [],
              "delegations": [
                {
                  "name": "delegationService",
                  "properties": {
                    "serviceName": "Microsoft.Network/dnsResolvers"
                  }
                }
              ]
            },
            {
              "name": "backend",
              "addressSpace": "10.2.0.32/27",
              "specialSubnet": false,
              "securityRules": [],
              "delegations": []
            },
            {
              "name": "frontend",
              "addressSpace": "10.2.0.64/27",
              "specialSubnet": false,
              "securityRules": [],
              "delegations": []
            }
          ]
        }
    },

  • DNS

  "dnsresolver_object": {
        "value": {
          "subnet": "dnsresolver"
        }
      },

or

• VPN Gateway

"vpn_object": {
    "value": {
      "sku": "Basic",
      "type": "Vpn",
      "addressPrefix": "172.16.24.0/24",
      "subnet": "GatewaySubnet",
      "generation": "Generation1",
      "keyVaultP2SCert": "<Secret Name from KeyVault for Public Root Certificate>"
    }
  },

• Virtual Machine

"vm_object_array": {
    "value": [
      {
        "name": "dev",
        "adminUsername": "azureuser",
        "vmSize": "Standard_DS1_v2",
        "keyVaultSSHKey": "<Secret Name from KeyVault for Public SSH Key>",
        "subnet": "backend",
        "ipaddress": "10.2.0.37",
        "imageReference": {
          "publisher": "Canonical",
          "offer": "UbuntuServer",
          "sku": "18.04-LTS",
          "version": "latest"
        },
        "osDisk": {
          "osType": "Linux",
          "createOption": "FromImage",
          "caching": "ReadWrite",
          "managedDisk": {
            "storageAccountType": "Premium_LRS"
          },
          "deleteOption": "Detach",
          "diskSizeGB": 30
        }
      }
    ]
  }

• Deploy using Bicep

  • Login to Azure

    az login --use-device-code

  • Change to the deploy folder

  • Run Bicep and use the parameters file updated and saved above

    az deployment sub create --name dev --location uksouth --template-file main.bicep --parameters main.parameters.json

  • Post deployment go to the VPN Gateway and reset it. Sometimes the client doesn't connect and this resolves that issue.

  • In to VPN Gateway download and install the VPN Client from the Point-to-site configuration section.

  • Connect to the VPN before moving to the next section

Process to connect to a DevContainer

• Connect to the remote host using ssh (e.g. [email protected]) by running command: Remote-SSH: Connect to Host
• On the remote VM clone a repo (e.g. git clone ……)
• Run command : Remote-Containers: Open Folder in container
• Select the folder you want and VS Code will create/open the devcontainer on the remote VM.
  

Example VS Code Commands

• To edit / Open SSH configuration file:
  • Remote-SSH: Open SSH Configuration File
• To connect to remote host:
  • Remote-SSH: Connect to Host
  • Remote-SSH: Connect Current Windows to Host
• Reload VS Code Window if any config changes have been made (e.g. added new SSH Host in config file):
  • Developer: Reload Window
• Create new/replace dev container configuration files in a repo. :
  • Remote-Containers: Add Development Container Configuration Files...
• To configure the remote container:
  • Remote-Containers: Configure Container Features
• Once on remote VM to open a dev container to can either run:
  • Remote-Containers: Open Folder in Container

Links

• Developing inside a Container
• Create a development container
• dev container.json reference
• Connect to remote Docker over SSH
• Generate a new SSH Key and adding it to the ssh-agent

Troubleshooting

• If you battle to SSH into the VM with an error related to man in the middle attack. Check the .ssh/known_hosts file for an entry for the same IP address. If so, delete the entry.
• When logging in to Azure via cli (az login) you might get an error with a redirect. Look at the page and add the port highlighted to PORT forwarding. (e.g. Port 44563 -> localhost:44563)
  • Login with az login:
    • 
  • Login with your azure account when prompted.
  • Page can't be reached error could to shown:
    • 
  • Need to add port forwarding for the port highlighted above:
    • 
  • The page can't be reached with refresh automatically and log in once the port has been forwarded.
  • Note: The port will change every time you login.
• SSH Authentication issues with Azure DevOps
  • Make sure the key pair created for Azure DevOps is called id_rsa
  • Add a SSH key to the development VM (.ssh) and to Azure DevOps.
  • Add a SSH key to the dev container (.ssh) and to Azure DevOps. Plus run the ssh-add <.ssh/is_rsa> statement to link the key correctly

Links

• devcontainer ref
• ssh
• Develop with Remote Host
• CodeSpaces
• Create VPN Gateway
• Setup CA in Ubuntu
• Public Key Encryption