MongoDB Replica Set – The value of parameter linuxConfiguration.ssh.publicKeys.keyData is invalid – CentOS

This is concerning the Azure Deployment Template for a MongoDB Replica Set defined here mongodb-replica-set-centos.

When I run the recommended deployment commands to deploy the replica set, namely

az group create --name <resource-group-name> --location <resource-group-location> # Use this command when you need to create a new resource group for your deployment.
az deployment group create --resource-group <my-resource-group> --template-uri https://raw.githubusercontent.com/migr8/AzureDeploymentTemplates/main/mongo/mongodb-replica-set-centos/azuredeploy.json

where the resource group is already set up. I receive the following error:

{
  "status": "Failed",
  "error": {
    "code": "DeploymentFailed",
    "message": "At least one resource deployment operation failed. Please list deployment operations for details. Please see https://aka.ms/DeployOperations for usage details.",
    "details": [
      {
        "code": "Conflict",
        "message": "{rn  "status": "Failed",rn  "error": {rn    "code": "ResourceDeploymentFailure",rn    "message": "The resource operation completed with terminal provisioning state 'Failed'.",rn    "details": [rn      {rn        "code": "DeploymentFailed",rn        "message": "At least one resource deployment operation failed. Please list deployment operations for details. Please see https://aka.ms/DeployOperations for usage details.",rn        "details": [rn          {rn            "code": "BadRequest",rn  "message": "{\r\n  \"error\": {\r\n    \"code\": \"InvalidParameter\",\r\n    \"message\": \"The value of parameter linuxConfiguration.ssh.publicKeys.keyData is invalid.\",\r\n    \"target\": \"linuxConfiguration.ssh.publicKeys.keyData\"\r\n  }\r\n}"rn          }rn        ]rn      }rn    ]rn  }rn}"
      },
      {
        "code": "Conflict",
        "message": "{rn  "status": "Failed",rn  "error": {rn    "code": "ResourceDeploymentFailure",rn    "message": "The resource operation completed with terminal provisioning state 'Failed'.",rn    "details": [rn      {rn        "code": "DeploymentFailed",rn        "message": "At least one resource deployment operation failed. Please list deployment operations for details. Please see https://aka.ms/DeployOperations for usage details.",rn        "details": [rn          {rn            "code": "BadRequest",rn            "message": "{\r\n  \"error\": {\r\n    \"code\": \"InvalidParameter\",\r\n    \"message\": \"The value of parameter linuxConfiguration.ssh.publicKeys.keyData is invalid.\",\r\n    \"target\": \"linuxConfiguration.ssh.publicKeys.keyData\"\r\n  }\r\n}"rn          }rn        ]rn      }rn    ]rn  }rn}"
      }
    ]
  }
}

The problem field is in both primary-resources.json and secondary-resources.json appears to be

    "variables": {
        "subnetRef": "[resourceId('Microsoft.Network/virtualNetworks/subnets', parameters('subnet').vnet, parameters('subnet').name)]",
        "securityGroupName": "[concat(parameters('namespace'), parameters('vmbasename'), 'nsg')]",
        "linuxConfiguration": {
            "disablePasswordAuthentication": true,
            "ssh": {
                "publicKeys": [
                    {
                        "path": "[concat('/home/', parameters('adminUsername'), '/.ssh/authorized_keys')]",
                        "keyData": "[parameters('adminPasswordOrKey')]"
                    }
                ]
            }
        }
    },

And ascociated with the variable adminPasswordOrKey. I have tried changing this to be both standard passwords and SSH keys of varying bit-depth, no luck…

How can I fix this?

Repro steps

1. Run az group create --name <resource-group-name> --location <resource-group-location> where resource group exists.
2. Run az deployment group create --resource-group <my-resource-group> --template-uri https://raw.githubusercontent.com/migr8/AzureDeploymentTemplates/main/mongo/mongodb-replica-set-centos/azuredeploy.json and step through the prompts
3. Enter the relevant in formation.

Further Investigation

I have just seen this answer (https://stackoverflow.com/a/60860498/626442) saying specifically that

Note: Please note that the only allowed path is /home//.ssh/authorized_keys due to a limitation of Azure.

I have changed this value of the path, no joy, same error. :'[