Cloud Build Overview

Google Cloud Build is a fully managed continuous integration and continuous delivery (CI/CD) platform that lets you build, test, and deploy software on Google Cloud. It executes your builds as a series of steps in Docker containers, giving you full control over the build environment while eliminating the need to manage build servers.

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What Is Cloud Build?

Cloud Build is a serverless CI/CD service. You define build steps in a configuration file, and Cloud Build executes them in isolated containers. Each step runs in its own container, and steps can share data through a persistent workspace volume.

Key Characteristics

Characteristic	Description
Serverless	No build servers to provision or manage
Container-based	Each build step runs in a Docker container
Fast	Parallel step execution and build caching
Secure	Runs in isolated environments with IAM-based access
Flexible	Any Docker image can be a build step
Integrated	Native integration with GCP services
Free tier	120 build-minutes per day for the first region

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Build Configuration

Cloud Build uses a cloudbuild.yaml (or cloudbuild.json) file to define the build pipeline:

steps:
  # Step 1: Install dependencies
  - name: 'node:18'
    entrypoint: 'npm'
    args: ['install']

  # Step 2: Run tests
  - name: 'node:18'
    entrypoint: 'npm'
    args: ['test']

  # Step 3: Build the Docker image
  - name: 'gcr.io/cloud-builders/docker'
    args: ['build', '-t', 'gcr.io/my-project/my-app:latest', '.']

images:
  - 'gcr.io/my-project/my-app:latest'

options:
  machineType: 'E2_HIGHCPU_8'
  logging: CLOUD_LOGGING_ONLY

Build Steps

Each step is a container execution:

Field	Description
name	Docker image to use for this step
args	Arguments passed to the container entrypoint
entrypoint	Override the default entrypoint
dir	Working directory within the container
id	Unique identifier for the step (for dependencies)
waitFor	Steps that must complete before this step runs
env	Environment variables for the step
secretEnv	Secret Manager references for sensitive variables
timeout	Maximum duration for the step

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Cloud Builders

Cloud Build provides pre-built builder images for common tools:

Builder	Image	Purpose
Docker	gcr.io/cloud-builders/docker	Build and push Docker images
gcloud	gcr.io/cloud-builders/gcloud	Run gcloud CLI commands
kubectl	gcr.io/cloud-builders/kubectl	Deploy to GKE
gsutil	gcr.io/cloud-builders/gsutil	Interact with Cloud Storage
git	gcr.io/cloud-builders/git	Git operations
npm	gcr.io/cloud-builders/npm	Node.js package management
go	gcr.io/cloud-builders/go	Build Go applications
maven	gcr.io/cloud-builders/mvn	Build Java/Maven projects

You can also use any public Docker image or your own custom builder images.

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Running Builds

Manual Build

# Run a build from the current directory
gcloud builds submit --config=cloudbuild.yaml .