Heroku Buildpack for Node.js
This is the official Heroku buildpack for Node.js apps.
Documentation
For more information about using this Node.js buildpack on Heroku, see these Dev Center articles:
For more general information about buildpacks on Heroku:
Using the Heroku Node.js buildpack
It's suggested that you use the latest version of the release buildpack. You can set it using the heroku-cli.
heroku buildpacks:set heroku/nodejs
Your builds will always used the latest published release of the buildpack.
If you need to use the git url, you can use the latest tag to make sure you always have the latest release. The main branch will always have the latest buildpack updates, but it does not correspond with a numbered release.
heroku buildpacks:set https://github.com/heroku/heroku-buildpack-nodejs#latest -a my-app
Locking to a buildpack version
Even though it's suggested to use the latest release, you may want to lock dependencies - including buildpacks - to a specific version.
First, find the version you want from
the list of buildpack versions.
Then, specify that version with buildpacks:set:
heroku buildpacks:set https://github.com/heroku/heroku-buildpack-nodejs#v176 -a my-app
Chain Node with multiple buildpacks
This buildpack automatically exports node, npm, and any node_modules binaries
into the $PATH for easy use in subsequent buildpacks.
Feedback
Having trouble? Dig it? Feature request?
Development
Prerequisites
For local development, you may need the following tools:
Deploying an app with a fork or branch
To make changes to this buildpack, fork it on GitHub.
Push up changes to your fork, then create a new Heroku app to test it,
or configure an existing app to use your buildpack:
# Create a new Heroku app that uses your buildpack
heroku create --buildpack <your-github-url>
# Configure an existing Heroku app to use your buildpack
heroku buildpacks:set <your-github-url>
# You can also use a git branch!
heroku buildpacks:set <your-github-url>#your-branch
Downloading Plugins
In order to download the latest plugins that have been released, run the following:
plugin/download.sh v$VERSION
Make sure the version is in the format v#, ie. v7.
Tests
The buildpack tests use Docker to simulate
Heroku's stacks.
To run the test suite:
make test
Or to just test a specific stack:
make heroku-20-build
make heroku-22-build
The tests are run via the vendored
shunit2
test framework.
Debugging
To display the logged build outputs to assist with debugging, use the "echo" and "cat" commands. For example:
test() {
local log_file var
var="testtest"
log_file=$(mktemp)
echo "this is the log file" > "$log_file"
echo "test log file" >> "$log_file"
# use `echo` and `cat` for printing variables and reading files respectively
echo $var
cat $log_file
# some cases when debugging is necessary
assertEquals "$var" "testtest"
assertFileContains "test log file" "$log_file"
}
Running the test above would produce:
testtest
this is the log file
test log file
The test output writes to $STD_OUT, so you can use cat $STD_OUT to read output.