Spinnaker Foremast

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Foremast is a Spinnaker pipeline and infrastructure configuration and templating tool. Just create a couple JSON configuration files and then manually creating Spinnaker pipelines becomes a thing of the past.


Why Foremast?

  • No manual creation of pipelines in the Spinnaker UI
  • Reproducible and versioned Spinnaker pipelines
  • Standardized pipelines with flexibilty for application specific needs

With Foremast, Developers create a couple simple JSON configs per application. These configs provide details on the pipeline and infrastructure specific to the application’s needs. Foremast takes those configs, renders some Jinja2 templates, and then acts as a client for the Spinnaker Gate API. Foremast comes with generic templates for creating a simple pipeline but it can also point to external templates for custom pipelines that fit any workflow.

Foremast Features

  • Dynamically generate Spinnaker pipelines based on JSON configs
  • Customizable pipelines through external Jinja2 Templates, see Foremast templates for examples
  • Dynamically generate AWS infrastructure based on pipeline configs
  • Set up resources not defined in Spinnaker, such as S3 buckets and IAM roles
  • Support for AWS Lambda pipelines

Getting Started

Take a look at quick start guide for a quick introduction on how to use Foremast.

We also have a blog post to help you get started: Automate Spinnaker Pipeline Creation


All the documentation can be viewed on Read the Docs. You can find all configuration options, code information, and better examples there.


See the contribution guide for information on code style, contributing, and testing.

Getting Help

For questions, support, or friendly conversation you can find us on Gitter.

More Details


Installing the package will provide CLI commands for convenience.

virtualenv -p python3 venv
source venv/bin/activate
pip install foremast

Entry Points

Foremast has a few easy to use CLI endpoints.

  • foremast-pipeline - Creates an application and pipeline Spinnaker
  • foremast-infrastructure - Sets up AWS infrastructure like s3, iam, elb, and security groups
  • foremast-pipeline-onetime - Generates a pipeline for deploying to one specific account
  • foremast-scaling-policy - Creates and attaches a scaling policy to an application server group.
  • foremast-pipeline-rebuild - rebuild pipelines after changes have been made

You can run any of these entries points from the command line. They rely on environment variables and are ideal for running in a Jenkins job

PROJECT=forrest GIT_REPO=core RUNWAY_DIR=path/to/pipeline_configs foremast-pipeline

Foremast Configuration

A file at {pwd}/.foremast/foremast.cfg, ~/.foremast/foremast.cfg, or /etc/foremast/foremast.cfg needs to exist in order to run foremast.

domain = example.com
envs = dev,stage,prod
regions = us-east-1
gate_api_url = http://gate.example.com:8084

Runway Configuration Files

To begin using Foremast, you must have a few JSON configuration files defined for each application


This file will be needed for each application. Foremast has a lot of defaults in place for pipeline.json, take a look at the pipeline.json docs for all options.


    "deployment": "spinnaker"

Example Deployment Environments Override

Custom deployment environment order and selection can be provided in the env key. When missing, the default provided is {"env": ["stage", "prod"]}. Here, the order matters and Pipeline will be generated in the given order.

    "deployment": "spinnaker",
    "env": [


Each deployment environment specified in the pipeline.json file will need an accompanying application-master-{env}.json file in the same directory.

The `application-master-{env} files have a lot of exposed values with sane defaults. Please take a look at the application.json docs for all options.

application-master-{env}.json example

  "security_group": {
    "description": "something useful",
    "elb_extras": ["sg_offices"],
    "ingress": {
    "egress": ""
  "app": {
    "instance_type": "t2.small",
    "app_description": "Edge Forrest Demo application",
    "instance_profile": "forrest_edge_profile"
  "elb": {
    "subnet_purpose": "internal",
    "target": "TCP:8080",
    "ports": [
      {"loadbalancer": "HTTP:80", "instance": "HTTP:8080"}
  "asg": {
    "subnet_purpose": "internal",
    "min_inst": 1,
    "max_inst": 1,
    "scaling_policy": {
        "metric": "CPUUtilization",
        "threshold": 90,
        "period_minutes": 10,
        "statistic": "Average"
  "regions": ["us-east-1"],
  "dns" : {
    "ttl": 120

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