Partial Bicep file to flip a property on an existing resource

[stan-sz]

Scenario: flip a property on all existing resources of a given type across RGs or regions.

Can below syntax (and semantics) be possible to just modify a property on an existing resource (see also #9033):

param accountName string
param location string

resource sa 'Microsoft.Storage/storageAccounts' existing = {
  name: accountName
  location: location
  properties: {
    supportsHttpsTrafficOnly: true
  }
}

This could help turn Bicep to be declarative language to run some operator actions instead of a full deployment of all resources (the idea for the snippet was taken from #8725).

[Stefan Ivemo (StefanIvemo)]

I would use Azure Policy and remediation tasks to solve this. https://learn.microsoft.com/en-us/azure/governance/policy/how-to/remediate-resources?tabs=azure-portal

[stan-sz]

@brwilkinson - no progress on my end. I'd appreciate if you could drive this.

[Ben Wilkinson (brwilkinson)]

Here is something interesting that I spotted with the AKS RP today with the latest API

• It looks like they created their own incremental mode for adding or modifying individual properties 😁

resource AKS 'Microsoft.ContainerService/managedClusters@2023-01-01' = {
  name: 'aeu1-pe-ctl-d1-aks01'
  location: resourceGroup().location
  properties: {
    mode: 'Incremental'
    azureMonitorProfile: {
      metrics: {
        enabled: true
        kubeStateMetrics: {
          metricLabelsAllowlist: ''
          metricAnnotationsAllowList: ''
        }
      }
    }
  }
}

[stan-sz]

This is exactly what this issue is about - have such capability at the ARM level, instead of having RPs implement that individually. It also circles back to #3351 about what does null vs omitting a property mean.

[Ben Wilkinson (brwilkinson)]

I just want to also add a comment about why this isn't currently technically supported.

Since the ARM template performs a PUT method and to do the desired request mentioned here, it would be a PATCH method, which is not currently supported in ARM template deployments, as far as I am aware.

• https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/PUT
• https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/PATCH

[Ben Wilkinson (brwilkinson)]

I put this repo together, just for fun, for a demo on the current workaround.

• https://github.com/brwilkinson/Bicep_Merge_Proto

This is just merging subnets, since for some reason people ask about this one. I actually use this same technique in my App Service templates to merge app config.

I decided to move to a generic "test if resource exists by resourceid" deploymentScript, since that was an improvement on what I was previously doing, which was using a feature flag set on the initial deployment (which I now removed).

This isn't it the ask of this thread, which vis an actual "patch" method.

[Ben Wilkinson (brwilkinson)]

Moved this to an issue, so going to close here.

[Ben Wilkinson (brwilkinson)]

new issue:

• Partial Bicep file to flip a property on an existing resource (PATCH or PUT/CH) method for ARM #10781