Heroku buildpack: swift

This is a Heroku buildpack for Swift apps that are powered by the Swift Package Manager.

Usage

Example usage:

$ ls
Procfile Package.swift Sources

$ heroku create --buildpack vapor/vapor

$ git push heroku master
remote: -----> Swift app detected
remote: -----> Installing clang 5.0.0
remote: -----> Installing swiftenv
remote: -----> Installing Swift 4.2.4
remote: -----> Building package (release configuration)
remote: -----> Installing dynamic libraries
remote: -----> Installing binaries

You can also add it to upcoming builds of an existing application:

$ heroku buildpacks:set vapor/vapor

The buildpack will detect your app as Swift if it has a Package.swift file in the root.

Procfile

Using the Procfile, you can set the process to run for your web server. Any binaries built from your Swift source using swift package manager will be placed in your $PATH.

Example Procfile for Vapor 2 apps:

web: Run --env=production --port=$PORT

Example Procfile for Vapor 3 apps:

web: Run serve --env production --hostname 0.0.0.0 --port $PORT

Specify a Swift version

The buildpack defaults to Swift 4.2.4 to maintain compatibility with Swift 3 projects. If you want to use the latest and greatest, or need a specific version – including snapshots, create a file called .swift-version in the root of the project folder with the desired version number inside.

$ echo '5.0.1' > .swift-version

The .swift-version file is completely compatible with swiftenv.

NOTE: Since there are frequent Swift language changes, it's advised that you pin to your Swift version.

Active build configuration

By default, the buildpack will use the release build configuration to enable compiler optimizations. If you are experiencing mysterious crashes, you can try disabling them by setting the SWIFT_BUILD_CONFIGURATION to debug, then redeploying.

$ heroku config:set SWIFT_BUILD_CONFIGURATION=debug
$ git commit -m "Change to debug configuration on Heroku" --allow-empty
$ git push heroku master
...
remote: -----> Building package (debug configuration)
...

Hooks

You can place custom scripts to be ran before and after compiling your Swift source code inside the following files in your repository:

• bin/pre_compile
• bin/post_compile

This is useful if you would need to install any other dependencies.

Using the latest source code

The vapor/vapor buildpack from the Heroku Buildpack Registry represents the latest stable version of the buildpack. If you'd like to use the source code from this Github repository, you can set your buildpack to the Github URL:

$ heroku buildpacks:set https://github.com/vapor-community/heroku-buildpack.git