fleet/docs/Contributing/Building-Fleet.md

Building Fleet

• Building the code
  • Quickstart
  • Clone and build
  • Details
• Development infrastructure
  • Starting the local development environment
  • Running Fleet using Docker development infrastructure
• Debugging with Delve debugger

Building the code

Quickstart

Install the dependencies as described in the following sections, then go to Clone and build

macOS

Enable the macOS developer tools:

xcode-select --install

Install Homebrew to manage dependencies, then:

brew install git go node yarn

Ubuntu

Install dependencies:

sudo apt-get install -y git golang make nodejs npm
sudo npm install -g yarn

Windows

To install dependencies, we recommend using Chocolatey. Always run Chocolatey in Powershell as an Administrator. Assuming your setup does not include any of our requirements, please run:

choco install nodejs git golang docker make python2 mingw
npm install -g yarn

Note: all packages default to the latest versions. To specify a version, place --version <version-number> after each package. You may also install all packages manually from their websites if you prefer.

After installing the packages, you must use Git Bash to continue with the next section.

If you plan to use WSL on your windows development environment, you can configure Docker to WSL integration by following the steps in Microsoft's WSL Documentation.

Clone and build

git clone https://github.com/fleetdm/fleet.git
cd fleet
make deps
make generate
make

The binaries are now available in ./build/.

Details

To set up a working local development environment, you must install the following minimum toolset:

• Go
• Node.js and Yarn
• GNU Make (probably already installed if you're on macOS/Linux)

Once you have those minimum requirements, check out this Loom video that walks through starting up a local development environment for Fleet.

For a text-based walkthrough, continue through the following steps:

First, you will need to install Fleet's dependencies.

To do this, run the following from the root of the repository:

make deps

When pulling changes, it may be necessary to re-run make deps if a new Go or JavaScript dependency was added.

Generating the packaged JavaScript

To generate all necessary code (bundling JavaScript into Go, etc.), run the following:

make generate

Automatic rebuilding of the JavaScript bundle

Usually, make generate takes the JavaScript code, bundles it into a single bundle via Webpack, and inlines that bundle into a generated Go source file so that all of the frontend code can be statically compiled into the binary. When you build the code after running make generate, include all of that JavaScript in the binary.

This makes deploying Fleet a dream since you only have to worry about a single static binary. If you are working on frontend code, it is likely that you don't want to have to manually re-run make generate and make build every time you edit JavaScript and CSS in order to see your changes in the browser. Instead of running make generate to solve this problem, before you build the Fleet binary, run the following command:

make generate-dev

Instead of reading the JavaScript from an inline static bundle compiled within the binary, make generate-dev will generate a Go source file which reads the frontend code from disk and run Webpack in "watch mode."

Note that when you run make generate-dev, Webpack will be watching the JavaScript files that were used to generate the bundle so that the process will be long-lived. Depending on your personal workflow, you might want to run this in a background terminal window.

After you run make generate-dev, run make build to build the binary, launch the binary and you'll be able to refresh the browser whenever you edit and save frontend code.

Compiling the Fleet binary

For convenience, Fleet includes a Makefile to build the code:

make

It's unnecessary to use Make to build the code, but using Make allows us to account for cross-platform differences more effectively than the go build tool when writing automated tooling. Use whichever you prefer.

Development infrastructure

The following assumes that you already installed Docker and Docker Compose (installed by default with Docker on macOS and Windows).

Starting the local development environment

To set up a canonical development environment via Docker, run the following from the root of the repository:

docker-compose up

Note: you can customize the DB Docker image via the environment variables FLEET_MYSQL_IMAGE and FLEET_MYSQL_PLATFORM. For example:

• To run in macOS M1, set FLEET_MYSQL_IMAGE=arm64v8/mysql:oracle FLEET_MYSQL_PLATFORM=linux/arm64/v8
• To test with MariaDB, set FLEET_MYSQL_IMAGE to mariadb:10.6 or the like (note MariaDB is not officially supported).

Stopping the local development environment

If you'd like to shut down the virtual infrastructure created by Docker, run the following from the root of the repository:

docker-compose down

Setting up the database tables

Once you docker-compose up and are running the databases, you can build the code and run the following command to create the database tables:

./build/fleet prepare db --dev

Running Fleet using Docker development infrastructure

To start the Fleet server backed by the Docker development infrastructure, run the Fleet binary as follows:

./build/fleet serve --dev

Developing the Fleet UI

When the Fleet server is running, the Fleet UI is accessible by default at https://localhost:8080.

Note that ./build/fleet serve --dev requires the use of make generate-dev because the server will not use bundled assets in this mode. (You may see an error mentioning a template not found when visiting the website otherwise.)

By default, Fleet will try to connect to servers running on default ports on localhost. Depending on your browser's settings, you may have to click through a security warning.

If you're using the Google Chrome web browser, you can always automatically bypass the security warning. Visit chrome://flags/#allow-insecure-localhost and set the "Allow invalid certificates for resources loaded from localhost." flag to "Enabled."

Note: in Chrome version 88, there is a bug where you must first enable chrome://flags/#temporary-unexpire-flags-m87. The chrome://flags/#allow-insecure-localhost flag will then be visible again.

The Fleet UI is developed with Typescript using the React library and SCSS for styling. The source code can be found in the frontend directory.

Debugging with Delve debugger

The Delve Go debugger can be used for debugging the Fleet binary.

Use the following command in place of make and ./build/fleet serve --dev:

dlv debug --build-flags '-tags=full' ./cmd/fleet -- serve --dev

It is important to pass the -tags=full build flag; otherwise, the server will not have access to the asset files.

Attaching a debugger to a running server

You can also run delve in headless mode, which allows you to attach your preferred debugger client and reuse the same session without having to restart the server:

dlv debug --build-flags '-tags=full' --headless \
  --api-version=2 --accept-multiclient --continue \
  --listen=127.0.0.1:61179 ./cmd/fleet -- serve --dev

• If you're using Visual Studio Code, there's a launch configuration in the repo.
• If you're using vim with vimspector, you can use the following config:

{
  "configurations": {
    "Go: Attach to Fleet server": {
      "adapter": "multi-session",
      "variables": {
        "port": 61179,
        "host": "127.0.0.1"
      },
      "configuration": {
        "request": "attach",
        "mode": "remote"
      }
    }
  }
}