heroku-buildpack-timestamps

A buildpack that adds timestamps and durations to the logs output by Heroku builds, as a lightweight means of timing/profiling slow builds.

Usage

This buildpack does not replace your existing buildpack(s) but instead is added alongside them. It must be placed first in the buildpack list.

To do this:

1. Ensure the Heroku CLI is installed and up to date.
2. cd <path/to/your/app>
3. Check your app has an existing buildpack already configured, using: heroku buildpacks
4. Insert this buildpack before all others, using: heroku buildpacks:add --index=1 edmorley/timestamps

The next time your app is built, each line of the build logs will be prefixed with timestamps, and a duration shown at the end of each buildpack's compile.

For more information on buildpacks and how to configure them, see the Heroku buildpack documentation.

Example output

-----> Timestamp app detected
-----> Node.js app detected
2018-10-01 20:30:59        
2018-10-01 20:30:59 -----> Creating runtime environment
2018-10-01 20:30:59        
2018-10-01 20:30:59        NPM_CONFIG_LOGLEVEL=error
2018-10-01 20:30:59        YARN_PRODUCTION=true
2018-10-01 20:30:59        NODE_ENV=production
2018-10-01 20:30:59        NODE_MODULES_CACHE=true
2018-10-01 20:30:59        NODE_VERBOSE=false
2018-10-01 20:30:59        
2018-10-01 20:30:59 -----> Installing binaries
2018-10-01 20:30:59        engines.node (package.json):  10.11.0
2018-10-01 20:30:59        engines.npm (package.json):   unspecified (use default)
2018-10-01 20:30:59        engines.yarn (package.json):  1.11.1
2018-10-01 20:30:59        
2018-10-01 20:30:59        Resolving node version 10.11.0...
2018-10-01 20:31:00        Downloading and installing node 10.11.0...
2018-10-01 20:31:01        Using default npm version: 6.4.1
2018-10-01 20:31:01        Resolving yarn version 1.11.1...
2018-10-01 20:31:01        Downloading and installing yarn (1.11.1)...
2018-10-01 20:31:02        Installed yarn 1.11.1
2018-10-01 20:31:03        
2018-10-01 20:31:03 -----> Restoring cache
2018-10-01 20:31:03        - node_modules
2018-10-01 20:31:05        
2018-10-01 20:31:05 -----> Building dependencies
2018-10-01 20:31:06        Installing node modules (yarn.lock)
2018-10-01 20:31:07        yarn install v1.11.1
2018-10-01 20:31:08        success Already up-to-date.
2018-10-01 20:31:08        Done in 1.16s.
2018-10-01 20:31:08        
2018-10-01 20:31:08 -----> Caching build
2018-10-01 20:31:08        - node_modules
2018-10-01 20:31:15        
2018-10-01 20:31:15 -----> Pruning devDependencies
2018-10-01 20:31:15        Skipping because YARN_PRODUCTION is 'true'
2018-10-01 20:31:15        
2018-10-01 20:31:15 -----> Build succeeded!
2018-10-01 20:31:15 -----> Buildpack compile completed in 16s

Limitations

This buildpack wraps later buildpack's compile steps, by temporarily shadowing the real bash on PATH. As such, the other buildpack's compile steps must use the shebang #!/usr/bin/env bash rather than #!/bin/bash, or their log output will not be wrapped.

Official buildpacks known to be compatible:

• heroku/clojure
• heroku/gradle
• heroku/java
• heroku/nodejs
• heroku/php
• heroku/python
• heroku/ruby
• heroku/scala

Official buildpacks that are not yet compatible:

• heroku/go

Alternatives

There is heroku-buildpack-timings, however it requires moving the buildpack configuration to the deprecated heroku-buildpack-multi, rather than being able to use Heroku's native multi-buildpack support.