Parameters

Parameters are template inputs that users provide when creating a deployment. They allow templates to be flexible and reusable — the same template can deploy different configurations depending on the parameter values.

Definition

Parameters are defined in the parameters array of a Deployment Template or Resource Group Template:

parameters:
  - name: cpu
    type: number
    description: Number of vCPUs
    default: 4
  - name: adminPassword
    type: secureString
    description: Administrator password
  - name: features
    type: string
    description: "SQL features to install"
    default: "SQLENGINE,FULLTEXT,IS"
    optional: true
  - name: serverName
    type: string
    description: "Server name (lowercase only)"
    validation: "^[a-z0-9-]+$"

Properties

Property	Required	Type	Description
name	Yes	string	Parameter identifier (used in expressions as {{parameters.<name>}})
type	Yes	string	Data type — see Types below
description	No	string	Explains the parameter to the user in the deployment wizard
default	No	varies	Default value (prefilled in the UI, must match the declared type)
optional	No	bool	Whether the parameter can be left empty (default: false)
validation	No	string	Regex pattern the value must match

Note

optional and default are independent — you can use both, either, or neither:

• Neither: parameter is required, no prefilled value
• default only: parameter is required but prefilled with the default
• optional only: parameter can be left empty, no prefilled value
• Both: parameter can be left empty, prefilled with the default if provided

Types

Type	Description	Example values
string	Text value	"hello", "SQLENGINE,FULLTEXT"
number	Numeric value (int, float, decimal)	4, 32.5
bool / boolean	True or false	true, false
secureString	Sensitive text — masked in the portal UI and logs	passwords, API keys

Validation

Use the validation property to enforce a regex pattern on the parameter value:

- name: environment
  type: string
  description: Target environment
  validation: "^(Dev|Test|Prod)$"

Validation is checked at runtime. If the value doesn't match, the deployment fails with a validation error.

Parameter Flow

Parameters flow through the template hierarchy:

User fills parameters in Dune Portal
       |
       v
Deployment Template (parameters defined here)
       |
       v  templateParameters: cpu: "{{parameters.dbCpu}}"
       |
Resource Group Template (parameters received here)
       |
       v  cpu: "{{parameters.cpu}}"
       |
Used in any value within the template — resource fields, postConfig variables, tags, etc.

1. Define in the Deployment Template

# singlevm.dunedpt.yaml
parameters:
  - name: cpu
    type: number
    description: Number of vCPUs
    default: 4
resourceGroups:
  - name: vm
    template: singlevm
    templateVersion: 1.0.0
    templateParameters:
      cpu: "{{parameters.cpu}}"

2. Receive in the Resource Group Template

# singlevm.dunergt.yaml
parameters:
  - name: cpu
    type: number
    default: 4
resources:
  - type: computeNode
    computeType: virtualMachine
    name: vmsingle
    cpu: "{{parameters.cpu}}"
    ...

3. Or pass static values directly

You can also hardcode values in templateParameters without exposing them as deployment parameters:

resourceGroups:
  - name: vm
    template: singlevm
    templateVersion: 1.0.0
    templateParameters:
      cpu: 4                    # static — user never sees this

Accessing Parameters in Expressions

Use {{parameters.<name>}} to reference a parameter value in the template where it's defined:

svcName: "app-{{parameters.serviceName}}"
memory: "{{parameters.memory}}"
size: "{{parameters.userDbDiskSize}}"

{{parameters.<name>}} always resolves against the parameters of the current template's scope:

• In a Deployment Template — the deployment parameters
• In a Resource Group Template — the RGT parameters (received via templateParameters)

Reaching deployment parameters from RG scope

When a deployment template extends an RGT with inline resources or postConfig (see Deployment Template — Extending with Additional Resources), those entries run in resource group scope. There, {{parameters.<name>}} refers to the RGT's parameters, not the deployment's. Use {{deployment.parameters.<name>}} to reach deployment-level parameters from that scope:

# In a Deployment Template
parameters:
  - name: appName
    type: string
resourceGroups:
  - name: db
    template: mssqlvm
    templateVersion: 1.0.0
    templateParameters:
      sqlVersion: sql22dev
    resources:                                       # inline resources — run in RG scope
      - type: serviceAccount
        name: svcapp
        svcName: "{{deployment.parameters.appName}}-svc"   # reach the deployment param

See Expressions for the full expression reference.

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