Filtering nested arrays and selecting specific properties using az cli JMESPath

Question

I am trying to query a response from the following az command:

az provider operation show --namespace Microsoft.KeyVault

I want to query all operations that relate to secrets to be able to build a custom role for a RBAC enabled key vault. This is a short excerpt from the entire response:

{
    "displayName": "Microsoft Key Vault",
    "id": "/providers/Microsoft.Authorization/providerOperations/Microsoft.KeyVault",
    "name": "Microsoft.KeyVault",
    "operations": [
      {
        "description": "Registers a subscription",
        "displayName": "Register Subscription",
        "isDataAction": false,
        "name": "Microsoft.KeyVault/register/action",
        "origin": null,
        "properties": null
      },
      {
        "description": "Unregisters a subscription",
        "displayName": "Unregister Subscription",
        "isDataAction": false,
        "name": "Microsoft.KeyVault/unregister/action",
        "origin": null,
        "properties": null
      }
    ],
    "resourceTypes": [
      {
        "displayName": "Secret",
        "name": "vaults/secrets",
        "operations": [
          {
            "description": "View the properties of a secret, but not its value.",
            "displayName": "Read Secret Properties",
            "isDataAction": false,
            "name": "Microsoft.KeyVault/vaults/secrets/read",
            "origin": null,
            "properties": null
          },
          {
            "description": "Creates a new secret or updates the value of an existing secret.",
            "displayName": "Write Secret",
            "isDataAction": false,
            "name": "Microsoft.KeyVault/vaults/secrets/write",
            "origin": null,
            "properties": null
          }
        ]
      }
    ],
    "type": "Microsoft.Authorization/providerOperations"
}

I would like to extract the description as well as the name from the object in the array resourceTypes where resourceTypes.name=="vaults/secrets".

I am trying to build this gradually, but I am stuck on even filtering out this object. This is where I'm at, and I've derived this from the JMESPath documentation on filtering arrays:

az provider operation show --namespace Microsoft.KeyVault --query "[?resourceTypes.name=='vaults/secrets']"

This is just empty however.

The end result I am after is a tabular output with the description and name from each operation within the operations array.

Any help would be greatly appreciated.

β.εηοιτ.βε · Accepted Answer · 2022-06-27T06:51:31.567

The issue in your current query is that doing [] would assume you address an array at the root of your JSON, when what you have at the root of your JSON is a map:

{
  "resourceTypes": [
    {
      "name": "vaults/secrets",
    }
  ]
}

So, the beginning of the query to address your JSON should rather be

resourceTypes[?name == 'vaults/secrets']

While your query would work on a JSON looking like:

[
  {
    "resourceTypes": {
      "name": "vaults/secrets",
    }
  }
]

From there on, you need to query the operations array, so operations[] and do a multiselect hash to trim down the map to the fields you are looking for.

We end with the query:

resourceTypes[?name == 'vaults/secrets']
  .operations[]
  .{
    description: description, 
    name: name
  }

And, lastly, to format it in table, you can use the table output format of the Azure client.

We end up with the line:

az provider operation show \
  --namespace Microsoft.KeyVault \
  --query "resourceTypes[?name == 'vaults/secrets']
    .operations[]
    .{
      description: description, 
      name: name
    }" \
  --out table

Beautiful, thanks for taking the time to walk this through step by step. JMES has always been a bit of conondrum regarding arrays for me, but this clarifies a lot of things. — jokarl, Jun 27 '22 at 06:36

Filtering nested arrays and selecting specific properties using az cli JMESPath

1 Answers1