Setting up a Development Environment

Tilt is a great way to run OpenCost on a local or remote Kubernetes environment. Tilt automatically redeploys OpenCost when code or configuration changes, provides easy access to back end debugging, and automatically handles port forwarding.

Prerequisites

Required

• Delve and the Delve plugin for your preferred IDE or text editor
• Docker Desktop or Docker Engine
• Go
• Helm
• kind or your preferred tool for a Kubernetes development environment
• kubectl
• Node.js
• Tilt

Run OpenCost

1. In a terminal, run: helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
2. Update tilt-values.yaml or create a new yaml file to contain desired attributes - see documentation here.
3. Optional - configure JSON files for cloud integration(s) and a service key (see here).
4. Update Tiltfile to allow your remote Kubernetes contexts, if desired. See comment block near top of the Tiltfile. See documentation here.
5. If using kind, in a terminal, run kind create cluster to create local cluster, or set your Kubernetes context to the desired cluster.
6. Configure a tilt_config.json file - (see below section)[##tilt-command-options]
7. In a terminal, run tilt up at the root of the OpenCost repository. See Tilt Command Options below for more options.
8. Follow instructions to open the Tilt UI in browser (hit space, or navigate to http://localhost:10350)
9. As you update code, tilt_config.json, or tilt-values.yaml, Tilt will automatically watch relevant source code and recompile, build, deploy, and run tests.
10. tilt down will tear down resources created, otherwise they will continue to run indefinitely.
11. kind delete cluster will delete the local cluster, if desired.

Tilt Command Options

via tilt_config.json

The best way to configure OpenCost to use tilt is with a tilt_config.json file in the root of the OpenCost repository. The file must live there; a symlink is thebest alternative if you wish to store it elsewhere. This file is automatically reloaded in tilt when updated. Omitted values will use defaults. Example contents:

{
  "arch":"amd64",
  "cloud-integration":"../cloud-integration.json"
}

via CLI

These options can also be placed after tilt up --. Example command: tilt up -- --arch arm64 --docker-repo dockerhub-username --cloud-integration ../cloud-integration.json --service-key ../service-key.json Options defined from the CLI will override those from tilt_config.json.

Options

• arch Value: amd64(default),arm64 Optional. This is the CPU architecture of the cluster nodes used. The value is prepended to the docker image names (the -t flag in a Docker build command). See Docker Documentation.
• cloud-integration Value: path_to_cloud_integration_json_file Optional. Defaults to an empty string. This is the path to the JSON file to use for the cloud-integration secret. (See here for more.)[#..#configuration#configuration]
• delve-continue Value: true(default) or false Optional, defaults to true. Determines if the --continue flag is used with delve. By default, this will let applications start without a debugger attached. false will wait for a debugger to attach before starting.
• docker-repo Value: docker_hub_username or docker_repository Required for a remote cluster, optional for local.
• helm-values Optional. Defaults to ./tilt-values.yaml This it he path to the values.yaml file that will be used for the OpenCost helm chart.
• service-key path_to_service_key_json_file Optional. Defaults to an empty string. This is the path to the JSON file to use for the service-key secret. (See here for more.)[#..#configuration#configuration]
• port-costmodel Optional. Defaults to 9003. This is the port forwarded to localhost for the costmodel (back end). Note: In tilt_config.json, this is a string and must be in quotes, since Tilt options must be a bool or a string.
• port-debug Optional. Defaults to 40000. This is the port forwarded to localhost for delve. Note: In tilt_config.json, this is a string and must be in quotes, since Tilt options must be a bool or a string.
• port-prometheus Optional. Defaults to 9080. This is the port forwarded to localhost for Prometheus. Note: In tilt_config.json, this is a string and must be in quotes, since Tilt options must be a bool or a string.
• port-ui Optional. Defaults to 9090. This is the port forwarded to localhost for the web UI. Note: In tilt_config.json, this is a string and must be in quotes, since Tilt options must be a bool or a string.

Attach Debugger to the Back End

The OpenCost back end auto starts with delve by default. Configure your IDE or text editor to attach to http://localhost:40000 (or specified value of the port-debug option).