About This Repository

Summary

This repository is a fork of GoogleCloudPlatform/cloud-builders-community, modified to build Docker images remotely.

License

I do not claim the license of this repository myself, but inherit and follow the license of the repository from which I forked. Please refer to LICENSE if you want to know specific details.

Cloud Build Remote Build Step

Introduction

Some continuous integration workloads require special builder types. You may require things like:

1. High CPU/Memory machines
2. Custom image
3. GPUs attached
4. Fast or large disks
5. Machines in a particular network
6. Pre-emptibility

In these cases you can leverage Container Builder to trigger your builds and manage their workflow but run the actual build steps on an instance with exactly the configuration you need.

How?

When using the remote-builder image, the following will happen:

1. A temporary SSH key will be created in your Container Builder workspace
2. A instance will be launched with your configured flags
3. The workpace will be copied to the remote instance
4. Your command will be run inside that instance's workspace

Usage

In order to use this step, first build the builder:

gcloud builds submit --config ./cloudbuild.yaml .

Then, create an appropriate IAM role with permissions to create and destroy Compute Engine instances in this project:

export PROJECT=$(gcloud info --format='value(config.project)')
export PROJECT_NUMBER=$(gcloud projects describe $PROJECT --format 'value(projectNumber)')
export [email protected]
gcloud services enable cloudbuild.googleapis.com
gcloud services enable compute.googleapis.com
gcloud projects add-iam-policy-binding $PROJECT --member=serviceAccount:$CB_SA_EMAIL --role='roles/iam.serviceAccountUser' --role='roles/compute.instanceAdmin.v1' --role='roles/iam.serviceAccountActor'

Then, configure your build step as follows:

steps:
- name: gcr.io/$PROJECT_ID/docker-remote-builder
  env:
    - COMMAND=ls -la

This will launch an instance with the default parameters and then run the command ls -la inside the instance's workspace.

Configuration

The following options are configurable via environment variables passed to the build step in the env parameter:

Options	Description	Default
COMMAND	Command to run inside the remote workspace	None, must be set
USER_NAME	Username to use when logging into the instance via SSH	builder
REMOTE_WORKSPACE	Location on remote host to use as workspace	/home/${USERNAME}/workspace/
INSTANCE_NAME	Name of the instance that is launched	docker-remote-builder-$UUID
ZONE	Compute zone to launch the instance in	asia-southeast1-b
INSTANCE_ARGS	Parameters to the instance creation command. For a full list run gcloud compute instances create --help	--preemptible
INSTANCE_SPOT_ARGS	It has the same purpose as INSTANCE_ARGS and is used in conjunction with it	--no-restart-on-failure --maintenance-policy=TERMINATE --provisioning-model=SPOT --instance-termination-action=DELETE --max-run-duration=$INSTANCE_MAX_DURATION
INSTANCE_MAX_DURATION	The maximum uptime of the instance and is used in the default of INSTANCE_SPOT_ARGS	3600s
RETRIES	The number of retries to wait for the instance to start accepting SSH connections	10

Example

example directory contains example for building AMD64 and ARM64 multiplatform Docker image. The following command will build and push gcr.io/$PROJECT_ID/docker-remote-builder-example:0.0.0.

gcloud builds submit --config ./example/cloudbuild.yaml ./example/

Trade-offs

1. Paying for builder + VM
2. Spin up time of VM increases build time