Cloud Run service concept in GCP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Cloud Run service?

A Cloud Run service is a way to run your app or code in the cloud without managing servers. It automatically handles scaling and lets your app respond to web requests.

beginner

How does Cloud Run handle scaling?

Cloud Run automatically adds or removes instances of your app based on how many requests it gets. If no one uses it, it can scale down to zero, saving resources.

beginner

What is the role of a container in Cloud Run?

Your app runs inside a container, which is like a small package with everything your app needs. Cloud Run runs this container to serve your app.

intermediate

Can Cloud Run services be accessed publicly by default?

No, Cloud Run services are private by default. You can choose to allow public access or restrict it to certain users or networks.

beginner

What triggers a Cloud Run service to start running?

A Cloud Run service starts running when it receives a web request. It wakes up the container to handle the request and then can scale down when done.

What does Cloud Run automatically manage for you?

A Server provisioning and scaling

B Writing application code

C Database management

D Network hardware setup

Cloud Run automatically handles server provisioning and scaling so you don't have to manage servers.

What format must your app be packaged in to deploy on Cloud Run?

A Virtual machine image

B Executable binary

C Container image

D ZIP archive

Cloud Run runs container images that package your app and its environment.

What happens when no requests are sent to a Cloud Run service?

A It keeps running at full capacity

B It scales down to zero instances

C It crashes

D It sends an error message

Cloud Run scales down to zero instances when idle to save resources.

Which of these is NOT a feature of Cloud Run?

A Manual server setup

B Managed server infrastructure

C Automatic scaling

D Container-based deployment

Cloud Run does not require manual server setup; it manages infrastructure automatically.

How do users typically interact with a Cloud Run service?

A Via email

B By logging into a server

C Using FTP

D Through web requests

Cloud Run services respond to web requests like HTTP calls.

Explain what a Cloud Run service is and how it manages your app's availability.

Think about how your app wakes up only when needed.

Describe the role of containers in Cloud Run and why they are important.

Containers are like boxes holding your app and its tools.

Practice

1. What is the main benefit of using Cloud Run for your applications?

easy

A. You must manually scale your application.

B. You don't need to manage servers or infrastructure.

C. It only runs applications written in Python.

D. You need to configure virtual machines yourself.

Solution

1. Step 1: Understand Cloud Run's server management

   Cloud Run automatically manages the servers, so you don't have to.

2. Step 2: Compare other options

   Manual scaling and VM configuration are not needed with Cloud Run.

3. Final Answer:

   You don't need to manage servers or infrastructure. -> Option B

4. Quick Check:

   Serverless = No server management [OK]

Hint: Cloud Run means no server setup needed [OK]

Common Mistakes:

• Thinking you must manage servers manually
• Believing Cloud Run only supports one language
• Confusing Cloud Run with VM services

2. Which gcloud command correctly deploys a container image to Cloud Run?

easy

A. gcloud run deploy --image gcr.io/my-project/my-image

B. gcloud compute instances create --image gcr.io/my-project/my-image

C. gcloud app deploy --image gcr.io/my-project/my-image

D. gcloud container clusters create --image gcr.io/my-project/my-image

Solution

1. Step 1: Identify the correct service for deploying containers

   Cloud Run uses gcloud run deploy to deploy container images.

2. Step 2: Eliminate other commands

   compute instances is for VMs, app deploy is for App Engine, and container clusters create is for Kubernetes clusters.

3. Final Answer:

   gcloud run deploy --image gcr.io/my-project/my-image -> Option A

4. Quick Check:

   Cloud Run deploy = gcloud run deploy [OK]

Hint: Use 'gcloud run deploy' for Cloud Run containers [OK]

Common Mistakes:

• Using compute or app commands instead of run
• Confusing Kubernetes cluster commands with Cloud Run
• Missing the --image flag

3. Given this Cloud Run service configuration snippet, what happens when traffic increases?

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: hello-service
spec:
  template:
    spec:
      containers:
      - image: gcr.io/my-project/hello-image
        resources:
          limits:
            cpu: 1
            memory: 512Mi

medium

A. Cloud Run automatically creates more instances to handle the traffic.

B. The service crashes because CPU is limited to 1.

C. You must manually add more instances in the config.

D. Traffic is rejected when CPU limit is reached.

Solution

1. Step 1: Understand Cloud Run scaling behavior

   Cloud Run automatically scales container instances based on incoming traffic.

2. Step 2: Analyze resource limits

   CPU and memory limits set max per instance but do not prevent scaling.

3. Final Answer:

   Cloud Run automatically creates more instances to handle the traffic. -> Option A

4. Quick Check:

   Auto scaling = more instances on traffic rise [OK]

Hint: Cloud Run scales instances automatically with traffic [OK]

Common Mistakes:

• Thinking CPU limit stops scaling
• Believing manual scaling is required
• Assuming traffic is rejected on resource limits

4. You deployed a Cloud Run service but get an error: Container failed to start. What is a likely cause?

medium

A. The container image is too large to deploy.

B. You forgot to set the CPU limit in the deployment.

C. The container image does not have a listening port configured.

D. Cloud Run requires a VM instance to be created first.

Solution

1. Step 1: Check container requirements for Cloud Run

   Cloud Run requires the container to listen on a port for incoming requests.

2. Step 2: Evaluate other options

   CPU limits are optional, Cloud Run is serverless (no VM setup), and image size usually causes warnings, not start failure.

3. Final Answer:

   The container image does not have a listening port configured. -> Option C

4. Quick Check:

   Listening port missing = start failure [OK]

Hint: Containers must listen on a port for Cloud Run [OK]

Common Mistakes:

• Assuming VM setup is needed
• Blaming CPU limits for start failure
• Thinking image size causes start errors

5. You want to deploy a Cloud Run service that scales down to zero when idle but also supports up to 10 concurrent requests per instance. Which configuration is correct?

hard

A. Set --concurrency=1 and --min-instances=10 to scale down to zero.

B. Set --min-instances=1 and --concurrency=10 to scale to zero.

C. Set --max-instances=10 and --concurrency=1 to allow 10 concurrent requests.

D. Set --concurrency=10 and deploy normally; Cloud Run scales to zero automatically.

Solution

1. Step 1: Understand concurrency and scaling in Cloud Run

   Concurrency controls how many requests one instance handles; setting it to 10 allows 10 requests per instance.

2. Step 2: Understand scaling to zero behavior

   Cloud Run automatically scales down to zero when idle unless --min-instances is set above zero.

3. Final Answer:

   Set --concurrency=10 and deploy normally; Cloud Run scales to zero automatically. -> Option D

4. Quick Check:

   Concurrency 10 + no min-instances = scale to zero [OK]

Hint: No min-instances means auto scale to zero [OK]

Common Mistakes:

• Setting min-instances prevents scaling to zero
• Confusing max-instances with concurrency
• Assuming concurrency 1 means 10 requests