Throw error if the agent pool doesn't exist for Azure Pipelines scaler

[JorTurFer]

Discussed in #2323

Currently, the scaler doesn't throw any error if the poolId doesn't exist. Maybe we could validate if it exists IDK how to be more clear

[JorTurFer]

I'm working on this task, and I'm not sure in the best way to proceed. I mean, validate if the pool exists or not requires an extra request to check it because the Azure DevOps API returns 200 despite not existing pool (crazy).

Maybe we could add support to specify directly the pool name instead of the pooID, if we are going to do an extra request to check if it exists, why don't get the ID from the name directly and use that to check if it exists?

We could also don't support it or maintain both ways but IMHO, using the pool name instead of the ID is more user-friendly

WDYT @kedacore/keda-contributors ?

[JorTurFer]

These endpoints return the same json:

• https://dev.azure.com/{organization}/_apis/distributedtask/pools?poolIds={poolIds}
• https://dev.azure.com/{organization}/_apis/distributedtask/pools?poolName={poolName}

So maybe maintain the old method and add the new one it's not a drama (but again, honestly as a user I prefer to use pool name instead of a weird ID also despite the breaking change)

[JorTurFer]

I have to add tests and update e2e test also but my idea is something like this: #2370

[tomkerkhove]

These endpoints return the same json:

• https://dev.azure.com/{organization}/_apis/distributedtask/pools?poolIds={poolIds}
• https://dev.azure.com/{organization}/_apis/distributedtask/pools?poolName={poolName}

Can you share a payload?

So maybe maintain the old method and add the new one it's not a drama (but again, honestly as a user I prefer to use pool name instead of a weird ID also despite the breaking change)

Let's support both, end-users can then choose and most likely they will all use the name but let's give people options.

[JorTurFer]

Okey, I will take a look maintianing both :)
Related with the payload, I will add an example in half an hour (now I'm AFK)

[JorTurFer]

{
   "count":1,
   "value":[
      {
         "createdOn":"2021-03-03T10:30:47.017Z",
         "autoProvision":false,
         "autoUpdate":true,
         "autoSize":null,
         "targetSize":null,
         "agentCloudId":null,
         "createdBy":{
            "displayName":"xxxx",
            "url":"https://spsprodeus27.vssps.visualstudio.com/Axxxxxa4d-47xx-458b-be3c-xxxxxxxxxxxxxx/_apis/Identities/04b3xxxx-dcf1-68a5-xxxx-3be81f93f076",
            "_links":{
               "avatar":{
                  "href":"https://dev.azure.com/YYYYYY/_apis/GraphProfile/MemberAvatars/aad.MDRiM2IwOTItxxxxMS03OGE1LWEwZGEtM2JlODFmOTNmMDc2"
               }
            },
            "id":"04b3b092-dcf1-68a5-a0da-3be81f93f076",
            "uniqueName":"xxxxxxxxx@xxxxxx.com",
            "imageUrl":"https://dev.azure.com/yyyyyyy/_apis/GraphProfile/MemberAvatars/aad.MDRiM2IwOTItZGNmMS03OGE1LWEwZGEtM2JlODFmOTNmMDc2",
            "descriptor":"aad.MDRiM2IwOTItZGNmMS03OGE1LWEwZGEtM2JlODFmOTNmMDc2"
         },
         "owner":{
            "displayName":"xxxxx",
            "url":"https://spsprodeus27.vssps.visualstudio.com/Ac66d5a4d-4775-458b-be3c-xxxxxxxxxxxxxx/_apis/Identities/04xxxx92-dcf1-xxxx-a0da-3xxxxxxf076",
            "_links":{
               "avatar":{
                  "href":"https://dev.azure.com/yyyyyyyy/_apis/GraphProfile/MemberAvatars/aad.MDRiM2IwOTItZGNmMS03OGE1LWEwZGEtM2JlODFmOTNmMDc2"
               }
            },
            "id":"04b3b092-dcf1-68a5-xxxx-xxxxxxf076",
            "uniqueName":"xxxxx@xxxxx.com",
            "imageUrl":"https://dev.azure.com/yyyyyyy/_apis/GraphProfile/MemberAvatars/aad.MDRiM2IwOTItZGNmMS03OGE1LWEwZGEtM2JlODFmOTNmMDc2",
            "descriptor":"aad.MDRiM2IwOTItZGNmMS03OGE1LWEwZGEtM2JlODFmOTNmMDc2"
         },
         "id":19,
         "scope":"48953491-beb9-42fe-99af-xxxxxxxx",
         "name":"k8s-deploy",
         "isHosted":false,
         "poolType":"automation",
         "size":2,
         "isLegacy":false,
         "options":"none"
      }
   ]
}

But we only need this:

{
   "count":1,
   "value":[
      {
         "id":19,
      }
   ]
}