Dapr integration overview in Azure - Step-by-Step Execution

Process Flow - Dapr integration overview

Start Application

↓

Initialize Dapr Sidecar

↓

Application Sends Request

↓

Dapr Intercepts Request

↓

Dapr Calls Target Service or Component

↓

Response Returned via Dapr

↓

Application Receives Response

↓

End

This flow shows how an application uses Dapr sidecar to send and receive requests through Dapr, enabling easy integration with other services or components.

Execution Sample

Azure

app -> dapr sidecar -> service/component -> dapr sidecar -> app

This shows the path of a request from the app through Dapr to a service and back.

Process Table

Step	Action	Component	Result
1	Start Application	App	App is running and ready
2	Initialize Dapr Sidecar	Dapr Sidecar	Sidecar starts alongside app
3	App sends request	App	Request sent to Dapr sidecar
4	Dapr intercepts request	Dapr Sidecar	Request processed by Dapr
5	Dapr calls target service	Dapr Sidecar	Service receives request
6	Service processes request	Service	Service prepares response
7	Response sent back	Dapr Sidecar	Response routed back to app
8	App receives response	App	App processes response
9	End	App & Dapr	Request cycle complete

💡 Request cycle ends after app receives response

Status Tracker

Variable	Start	After Step 3	After Step 5	After Step 7	Final
Request	None	Sent to Dapr	Received by Service	Response sent back	Response received by App
Response	None	None	None	Sent to App	Processed by App

Key Moments - 3 Insights

Why does the application send requests to the Dapr sidecar instead of directly to the service?

Because Dapr sidecar handles service discovery, retries, and communication, simplifying the app code as shown in steps 3 and 4 of the execution_table.

What role does the Dapr sidecar play in the communication?

It acts as a proxy that intercepts requests and routes them to the correct service or component, as seen in steps 4 and 5.

When does the application receive the response?

After the service processes the request and sends the response back through Dapr, the app receives it at step 8.

Visual Quiz - 3 Questions

Look at the execution_table, at which step does the Dapr sidecar first handle the request?

A Step 4

B Step 3

C Step 5

D Step 6

💡 Hint

Check the 'Component' and 'Action' columns in execution_table rows 3 and 4.

According to variable_tracker, what is the state of the 'Response' variable after step 5?

A Sent to App

B None

C Processed by App

D Received by Service

💡 Hint

Look at the 'Response' row and the column 'After Step 5' in variable_tracker.

If the Dapr sidecar did not intercept the request, which step would be skipped?

A Step 7

B Step 3

C Step 4

D Step 8

💡 Hint

Refer to the execution_table to see where Dapr intercepts the request.

Concept Snapshot

Dapr integration overview:
- App runs with a Dapr sidecar
- App sends requests to sidecar
- Sidecar routes requests to services/components
- Responses return via sidecar to app
- Simplifies communication and adds features like retries

Full Transcript

This visual execution shows how an application integrates with Dapr. The app starts and runs alongside a Dapr sidecar. When the app sends a request, it goes first to the Dapr sidecar, which intercepts and processes it. The sidecar then calls the target service or component. The service processes the request and sends a response back through the sidecar. Finally, the app receives the response. This flow helps the app communicate easily and reliably with other services.

Practice

1. What is the main purpose of Dapr in cloud applications?

easy

A. To replace cloud providers completely

B. To simplify cloud app features without complex code

C. To create virtual machines automatically

D. To manage user interface design

Solution

1. Step 1: Understand Dapr's role

   Dapr helps developers by making common cloud app features easy to use without writing complex code.

2. Step 2: Compare options

   Options B, C, and D describe unrelated tasks. Only To simplify cloud app features without complex code matches Dapr's purpose.

3. Final Answer:

   To simplify cloud app features without complex code -> Option B

4. Quick Check:

   Dapr simplifies cloud features = A [OK]

Hint: Remember: Dapr eases cloud features, not replaces providers [OK]

Common Mistakes:

• Thinking Dapr replaces cloud providers
• Confusing Dapr with UI tools
• Assuming Dapr manages virtual machines

2. Which of the following is a valid Dapr configuration setting?

easy

A. samplingRate: 1

B. MaxInstances: 1000

C. AutoScale: off

D. UITheme: dark

Solution

1. Step 1: Identify common Dapr config options

   Dapr configuration often includes settings like tracing and security, e.g., samplingRate.

2. Step 2: Evaluate options

   Options A, B, and D are unrelated to Dapr's config. Only samplingRate: 1 is valid.

3. Final Answer:

   samplingRate: 1 -> Option A

4. Quick Check:

   Dapr config includes tracing = C [OK]

Hint: Look for tracing or security keywords in config [OK]

Common Mistakes:

• Choosing unrelated config keys
• Confusing Dapr config with app settings
• Selecting UI or scaling options not in Dapr

3. Given this Dapr component YAML snippet:

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: statestore
spec:
  type: state.azure.cosmosdb
  metadata:
  - name: url
    value: https://mycosmos.documents.azure.com:443/
  - name: masterKey
    value: secretkey
  - name: databaseName
    value: mydb

What does this configuration do?

medium

A. Defines a state store component using Azure Cosmos DB

B. Creates a new Cosmos DB database named 'mydb'

C. Sets up a message queue for app communication

D. Configures tracing for Dapr components

Solution

1. Step 1: Analyze the YAML kind and spec

   The kind 'Component' with type 'state.azure.cosmosdb' means it defines a state store using Cosmos DB.

2. Step 2: Understand metadata fields

   Metadata includes connection info (url, masterKey, databaseName) for Cosmos DB access, not creating DB or queues.

3. Final Answer:

   Defines a state store component using Azure Cosmos DB -> Option A

4. Quick Check:

   Component type state.azure.cosmosdb = D [OK]

Hint: Look for 'state.azure.cosmosdb' type to identify state store [OK]

Common Mistakes:

• Thinking it creates the database itself
• Confusing state store with message queue
• Assuming it configures tracing

4. You have this Dapr configuration snippet:

apiVersion: dapr.io/v1alpha1
kind: Configuration
metadata:
  name: myconfig
spec:
  tracing:
    samplingRate: "0.5"
  mtls:
    enabled: true

What is the error in this configuration?

medium

A. mtls cannot be enabled in Dapr configuration

B. metadata name must be 'default'

C. Missing component type field

D. samplingRate should be a number, not a string

Solution

1. Step 1: Check tracing samplingRate format

   samplingRate expects a numeric value, but "0.5" is a string (in quotes), which is invalid.

2. Step 2: Validate other fields

   mtls enabled is valid, component type is not required in Configuration kind, and metadata name can be custom.

3. Final Answer:

   samplingRate should be a number, not a string -> Option D

4. Quick Check:

   samplingRate type error = B [OK]

Hint: Check data types carefully in YAML values [OK]

Common Mistakes:

• Assuming mtls can't be enabled
• Expecting component type in Configuration
• Thinking metadata name must be 'default'

5. You want to secure communication between your microservices using Dapr. Which combination of settings should you configure?

hard

A. Only configure tracing to monitor traffic

B. Disable mTLS and increase component replicas

C. Enable mTLS in Dapr configuration and set tracing samplingRate

D. Use Dapr without any configuration changes

Solution

1. Step 1: Identify security features in Dapr

   Dapr supports mTLS (mutual TLS) to secure service-to-service communication.

2. Step 2: Combine security with observability

   Enabling mTLS secures communication; setting tracing samplingRate helps monitor traffic, both important.

3. Final Answer:

   Enable mTLS in Dapr configuration and set tracing samplingRate -> Option C

4. Quick Check:

   mTLS + tracing for secure, observable communication = A [OK]

Hint: Secure with mTLS and monitor with tracing [OK]

Common Mistakes:

• Disabling mTLS weakens security
• Ignoring tracing for observability
• Assuming no config needed for security