Event Grid subscriptions and filters in Azure - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create an Event Grid subscription with a filter on the event type.

Azure

az eventgrid event-subscription create --name mySubscription --source-resource-id /subscriptions/123/resourceGroups/myRG/providers/Microsoft.Storage/storageAccounts/myStorage [1] --endpoint https://myendpoint.com/api/events

Drag options to blanks, or click blank then click option'

A--included-event-types BlobCreated

B--included-event-types BlobDeleted

C--subject-begins-with /blobServices/default/containers/images/

D--subject-ends-with .jpg

Attempts:

3 left

💡 Hint

Common Mistakes

Using subject filters instead of event type filters.

Omitting the event type filter option.

The --included-event-types option filters events by their type. Here, we want to receive only BlobCreated events.

2fill in blank

medium

Complete the code to add a subject filter that only accepts events where the subject begins with a specific path.

Azure

az eventgrid event-subscription create --name mySubscription --source-resource-id /subscriptions/123/resourceGroups/myRG/providers/Microsoft.Storage/storageAccounts/myStorage --included-event-types BlobCreated [1] --endpoint https://myendpoint.com/api/events

Drag options to blanks, or click blank then click option'

A--subject-ends-with .png

B--subject-begins-with /blobServices/default/containers/images/

C--subject-contains images

D--subject-equals /blobServices/default/containers/images/

Attempts:

3 left

💡 Hint

Common Mistakes

Using --subject-ends-with instead of --subject-begins-with.

Using --subject-contains which is not a valid filter option.

The --subject-begins-with option filters events whose subject starts with the specified string.

3fill in blank

hard

Fix the error in the filter syntax to correctly filter events where the subject ends with '.jpg'.

Azure

az eventgrid event-subscription create --name mySubscription --source-resource-id /subscriptions/123/resourceGroups/myRG/providers/Microsoft.Storage/storageAccounts/myStorage --included-event-types BlobCreated [1] --endpoint https://myendpoint.com/api/events

Drag options to blanks, or click blank then click option'

A--subject-ends-with .jpg

B--subject-begin-with .jpg

C--subject-endswith .jpg

D--subject-ends .jpg

Attempts:

3 left

💡 Hint

Common Mistakes

Misspelling the filter option name.

Using incorrect suffix filter syntax.

The correct option for filtering events by subject suffix is --subject-ends-with.

4fill in blank

hard

Fill both blanks to create an Event Grid subscription with filters for event type and subject prefix.

Azure

az eventgrid event-subscription create --name mySubscription --source-resource-id /subscriptions/123/resourceGroups/myRG/providers/Microsoft.Storage/storageAccounts/myStorage [1] [2] --endpoint https://myendpoint.com/api/events

Drag options to blanks, or click blank then click option'

A--included-event-types BlobDeleted

B--subject-begins-with /blobServices/default/containers/videos/

C--included-event-types BlobCreated

D--subject-ends-with .mp4

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up event type and subject filter options.

Using incorrect filter values.

Use --included-event-types BlobCreated to filter event types and --subject-begins-with to filter subjects starting with the given path.

5fill in blank

hard

Fill all three blanks to create an Event Grid subscription with filters for event type, subject prefix, and subject suffix.

Azure

az eventgrid event-subscription create --name mySubscription --source-resource-id /subscriptions/123/resourceGroups/myRG/providers/Microsoft.Storage/storageAccounts/myStorage [1] [2] [3] --endpoint https://myendpoint.com/api/events

Drag options to blanks, or click blank then click option'

A--included-event-types BlobCreated

B--subject-begins-with /blobServices/default/containers/images/

C--subject-ends-with .png

D--included-event-types BlobDeleted

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong event type filter.

Confusing subject prefix and suffix filters.

Combine filters for event type (BlobCreated), subject prefix, and subject suffix to receive only matching events.

Practice

1. What is the main purpose of using filters in Azure Event Grid subscriptions?

easy

A. To receive only specific events based on criteria like event type or subject

B. To increase the number of events sent to subscribers

C. To block all events from being delivered

D. To change the event data before delivery

Solution

1. Step 1: Understand Event Grid subscriptions

   Subscriptions let you receive events from Azure services.

2. Step 2: Role of filters in subscriptions

   Filters help select only the events you want, based on event type or subject.

3. Final Answer:

   To receive only specific events based on criteria like event type or subject -> Option A

4. Quick Check:

   Filters select events = B [OK]

Hint: Filters pick events you want, ignoring others [OK]

Common Mistakes:

• Thinking filters increase event volume
• Believing filters block all events
• Assuming filters modify event data

2. Which of the following is the correct JSON snippet to filter events by subject prefix in an Event Grid subscription?

easy

A. "filter": { "subjectBeginsWith": "/blobServices/default/containers/images" }

B. "filter": { "subjectEndsWith": "/blobServices/default/containers/images" }

C. "filter": { "eventType": "Microsoft.Storage.BlobCreated" }

D. "filter": { "subjectContains": "images" }

Solution

1. Step 1: Identify subject prefix filter syntax

   The correct property to filter by subject prefix is "subjectBeginsWith".

2. Step 2: Match the correct JSON snippet

   "filter": { "subjectBeginsWith": "/blobServices/default/containers/images" } uses "subjectBeginsWith" with the correct path prefix.

3. Final Answer:

   "filter": { "subjectBeginsWith": "/blobServices/default/containers/images" } -> Option A

4. Quick Check:

   Prefix filter uses subjectBeginsWith = A [OK]

Hint: Prefix filters use subjectBeginsWith property [OK]

Common Mistakes:

• Confusing subjectEndsWith with subjectBeginsWith
• Using eventType instead of subject filter
• Using subjectContains which is not valid

3. Given this Event Grid subscription filter configuration:

{ "subjectBeginsWith": "/devices/", "subjectEndsWith": "/temperature" }

Which event subject will be delivered to the subscriber?

medium

A. /sensors/device123/temperature

B. /devices/device123/humidity

C. /devices/device123/temperature

D. /devices/temperature/device123

Solution

1. Step 1: Understand filter conditions

   The event subject must start with "/devices/" and end with "/temperature".

2. Step 2: Check each option

   /devices/device123/temperature matches both start and end. Others fail one condition.

3. Final Answer:

   /devices/device123/temperature -> Option C

4. Quick Check:

   Subject starts with /devices/ and ends with /temperature = A [OK]

Hint: Match both start and end strings exactly [OK]

Common Mistakes:

• Ignoring subjectEndsWith condition
• Confusing similar paths
• Assuming partial matches are enough

4. You wrote this filter in your Event Grid subscription:

{ "subjectBeginsWith": "/orders/", "subjectEndsWith": "/completed" }

But no events are received even though events exist. What is the likely issue?

medium

A. The subscription is disabled

B. The filter syntax is invalid JSON

C. Event Grid does not support subject filters

D. The subject filter is case-sensitive and event subjects differ in case

Solution

1. Step 1: Check filter syntax and support

   The JSON syntax is valid and Event Grid supports subject filters.

2. Step 2: Consider case sensitivity and subscription status

   Subject filters are case-sensitive; if event subjects differ in case, no match occurs. Subscription being disabled would stop all events, but question implies filter issue.

3. Final Answer:

   The subject filter is case-sensitive and event subjects differ in case -> Option D

4. Quick Check:

   Subject filters are case-sensitive = D [OK]

Hint: Remember filters are case-sensitive in Event Grid [OK]

Common Mistakes:

• Assuming filters ignore case
• Blaming JSON syntax without checking
• Ignoring subscription status

5. You want to create an Event Grid subscription that only receives events of type Microsoft.Storage.BlobCreated where the blob is in the container named images. Which filter configuration achieves this?

hard

A. { "eventType": "Microsoft.Storage.BlobDeleted", "subjectBeginsWith": "/blobServices/default/containers/images/" }

B. { "eventType": "Microsoft.Storage.BlobCreated", "subjectBeginsWith": "/blobServices/default/containers/images/" }

C. { "eventType": "Microsoft.Storage.BlobCreated", "subjectEndsWith": "/images" }

D. { "eventType": "Microsoft.Storage.BlobCreated" }

Solution

1. Step 1: Filter by event type

   The event type must be exactly "Microsoft.Storage.BlobCreated" to get blob creation events.

2. Step 2: Filter by subject prefix for container

   The subject prefix for blobs in the "images" container is "/blobServices/default/containers/images/".

3. Step 3: Combine filters correctly

   { "eventType": "Microsoft.Storage.BlobCreated", "subjectBeginsWith": "/blobServices/default/containers/images/" } combines both eventType and subjectBeginsWith correctly.

4. Final Answer:

   { "eventType": "Microsoft.Storage.BlobCreated", "subjectBeginsWith": "/blobServices/default/containers/images/" } -> Option B

5. Quick Check:

   Event type and subject prefix filter combined = C [OK]

Hint: Combine eventType and subjectBeginsWith for precise filtering [OK]

Common Mistakes:

• Using wrong event type
• Using subjectEndsWith instead of subjectBeginsWith
• Omitting container path in subject filter