Cloud Run for containerized services in GCP - Step-by-Step Execution

Process Flow - Cloud Run for containerized services

Write containerized app

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Build container image

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Push image to Container Registry

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Deploy image to Cloud Run

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Cloud Run creates service

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Service listens for requests

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Requests routed to container instances

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Scale instances up/down automatically

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Billing based on usage

This flow shows how you build a container, push it, deploy to Cloud Run, and how Cloud Run manages requests and scaling automatically.

Execution Sample

GCP

gcloud builds submit --tag gcr.io/my-project/my-app

gcloud run deploy my-service --image gcr.io/my-project/my-app --platform managed

# Service is live and scales automatically

This code builds a container image from your app and deploys it to Cloud Run, which then runs and scales your service.

Process Table

Step	Action	Input/Condition	Result/Output
1	Build container image	Source code + Dockerfile	Container image created
2	Push image	Container image	Image uploaded to Container Registry
3	Deploy to Cloud Run	Image URL	Cloud Run service created
4	Service starts	No requests yet	No container instances running
5	First request arrives	HTTP request	Cloud Run starts container instance
6	Handle request	Container instance running	Response sent to client
7	More requests	Increased traffic	Cloud Run scales instances up
8	Traffic drops	No requests	Cloud Run scales instances down to zero
9	Billing	Based on CPU, memory, and request time	Charges applied only when serving requests

💡 Execution stops when no requests remain and Cloud Run scales down to zero instances.

Status Tracker

Variable	Start	After Step 4	After Step 5	After Step 7	Final
Container Instances	0	0	1	3	0
Traffic Load	0	0	1 request	High requests	0
Billing Meter	0	0	Starts counting	Increases	Stops counting

Key Moments - 3 Insights

Why are there zero container instances before the first request?

Cloud Run scales to zero when idle to save resources, as shown in execution_table step 4.

How does Cloud Run know when to start more container instances?

It monitors incoming requests and scales up automatically, as seen in steps 5 and 7.

When does billing start and stop?

Billing starts when container instances handle requests (step 5) and stops when scaled down to zero (step 8).

Visual Quiz - 3 Questions

Look at the execution_table, how many container instances are running after step 7?

A 0

B 1

C 3

D 5

💡 Hint

Check the 'Container Instances' variable in variable_tracker after Step 7.

At which step does Cloud Run start the first container instance?

A Step 5

B Step 3

C Step 4

D Step 6

💡 Hint

Look at execution_table where the first request triggers container start.

If no requests come in, what happens to container instances according to the tables?

A They stay running

B They scale down to zero

C They increase

D They restart continuously

💡 Hint

See execution_table step 8 and variable_tracker final state.

Concept Snapshot

Cloud Run runs container images as services.
It automatically scales from zero to many instances.
You pay only when your service handles requests.
Deploy by pushing container image and running 'gcloud run deploy'.
Cloud Run manages infrastructure and scaling for you.

Full Transcript

Cloud Run lets you run containerized apps without managing servers. First, you build your app into a container image. Then you push this image to a container registry. Next, you deploy the image to Cloud Run, which creates a service. Initially, no container instances run until a request arrives. When a request comes, Cloud Run starts a container instance to handle it. If traffic grows, Cloud Run automatically adds more instances. When traffic stops, it scales down to zero to save resources. Billing is based on the time your containers run and handle requests. This makes Cloud Run efficient and cost-effective for running containerized services.