title | description | author | ms.author | ms.date | ms.topic | ms.service | ms.custom |
---|---|---|---|---|---|---|---|
About parameter exposure using the Azure Operator Service Manager (AOSM) CLI extension. |
About parameter exposure using the Azure Operator Service Manager (AOSM) CLI extension. |
pjw711 |
peterwhiting |
04/16/2024 |
concept-article |
azure-operator-service-manager |
This document explains how the Azure Operator Service Manager (AOSM) Azure CLI extension translates helm values and parameters in ARM templates into a configuration model exposed to an operator.
AOSM allows the publisher of a Network Function Definition Version (NFDV) to choose which parameters are configurable when deploying the Network Function (NF). AOSM also allows the designer of a Network Service Design Version (NSDV) to choose which parameters are configurable when deploying the Site Network Service (SNS).
The choice of which parameters are exposed is encoded in one or more schemas. The publisher defines the schema in a property of the NFDV (the deployParameters
property); the designer defines the schema in a separate Azure resource - the Configuration Group Schema (CGS). The CGS and NSDV must pass a set of parameters and values to the NFDV that match the schema in the NFDV.
The Azure CLI AOSM extension contains support for automatic generation of the NFDV deployParameters
property, the CGS, and the mappings that ensure all parameters are correctly passed to the NF at deployment time.
The Azure CLI AOSM extension az aosm nfd generate-config
command generates an input file. The input file varies based on the --definition-type
parameter. All variants contain the following parameter:
// If set to true, all NFD configuration parameters are made available to the designer, including optional parameters and those with defaults.
// If not set or set to false, only required parameters without defaults will be exposed.
"expose_all_parameters": false,
This parameter controls the parameter exposure behavior in the AOSM CLI extension.
Warning
By exposing all parameters you are also exposing all your defaults. Make sure your defaults do not contain any sensitive information.
expose_all_parameters
is always set to false
by default. The AOSM CLI:
- parses the Containerized Network Function (CNF) helm values or the Virtualized Network Function (VNF) Azure Resource Manager (ARM) template parameters
- generates a
deployParameters
schema in the NFDV that contains any required parameters that don't have a default value
For example, this excerpt of a VNF ARM template defines two parameters. One is required and one is optional.
"parameters": {
"required": {
"type": "string",
"metadata": {
"description": "A required parameter."
}
},
"optional": {
"type": "string",
"defaultValue": "optional"
"metadata": {
"description": "An optional parameter."
}
},
}
The AOSM CLI builds an NFDV that exposes the required
parameter in the deployParameters
property. The optional
parameter isn't exposed. At deployment time, the VNF deploys with optional
set to the default value of optional
. The user triggering the deployment must provide a value for required
.
The behavior is similar for CNFs. The AOSM CLI allows the user to provide a values.yaml
file that overrides the default values.yaml
file in the helm chart. This override values.yaml
file can contain parameters with or without values. The following excerpt of a values.yaml
override file shows a parameter with a value and a parameter without a value.
optional: "optional"
required:
The AOSM CLI builds an NFDV that exposes the required
parameter in the deployParameters
property. The optional
parameter isn't exposed. At deployment time, the CNF deploys with optional
set to the default value of optional
. The user triggering the deployment must provide a value for required
.
Important
The AOSM CLI validates that the default values.yaml
file in the helm chart is consistent with the chart by running helm template
. The CLI raises an error if this helm template
command fails.
The Azure AOSM CLI Extension supports making all parameters configurable. The required configuration in the input file generated by az aosm nfd generate-config
is:
// If set to true, all NFD configuration parameters are made available to the designer, including optional parameters and those with defaults.
// If not set or set to false, only required parameters without defaults will be exposed.
"expose_all_parameters": true,
The AOSM CLI Extension, if expose_all_parameters
is set to true
:
- parses the Containerized Network Function (CNF) helm values or the Virtualized Network Function (VNF) Azure Resource Manager (ARM) template parameters
- generates a
deployParameters
schema in the NFDV that contains all of the parsed parameters - any defaults in the ARM template or values configured in the helm values are configured as defaults in the NFDV
deployParameters
schema.
In all cases, all parameters exposed by the az aosm nfd build
command are added to the CGS during the az aosm nsd build
command. The AOSM CLI extension also adds some extra parameters to the CGS, not parsed from the ARM Template or helm values, such as customLocationId
and managedIdentityId
. These parameters are needed to deploy the Site Network Service on the target environment.