https://github.com/shlima/health_bit
Tiny health check of Rack apps like Rails, Sinatra for use with uptime checking systems like Kubernetes, Docker or Uptimerobot
https://github.com/shlima/health_bit
health health-check healthcheck rack ruby ruby-on-rails
Last synced: about 16 hours ago
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Tiny health check of Rack apps like Rails, Sinatra for use with uptime checking systems like Kubernetes, Docker or Uptimerobot
- Host: GitHub
- URL: https://github.com/shlima/health_bit
- Owner: shlima
- License: mit
- Created: 2020-05-07T19:29:27.000Z (over 5 years ago)
- Default Branch: master
- Last Pushed: 2023-03-15T21:38:13.000Z (over 2 years ago)
- Last Synced: 2025-09-06T04:57:22.481Z (about 1 month ago)
- Topics: health, health-check, healthcheck, rack, ruby, ruby-on-rails
- Language: Ruby
- Homepage:
- Size: 174 KB
- Stars: 112
- Watchers: 1
- Forks: 8
- Open Issues: 3
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE.txt
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README
[](https://rubygems.org/gems/health_bit)
# HealthBit
This gem was inspired by the [health_check](https://github.com/ianheggie/health_check), but is simpler and more
extensible and contains up to 95% less code.
Key differences:
* is a rack application (just a lambda function)
* can be used with rails, sinatra or any other rack application
* can add custom checks
* can add multiple endpoints with independent checks
* can use any rack middleware (such as http basic auth, IP whitelist)
## Toc
* [Installation](#installation)
* [Configuration](#configuration)
* [Add Checks](#add-checks)
* [Add a Route](#add-a-route)
* [Password Protection](#password-protection)
* [Multiple endpoints](#multiple-endpoints)
* [Custom formatter](#custom-formatter)
## Check Examples
* [Database check](#database-check)
* [Redis check](#redis-check)
* [Sidekiq check](#sidekiq-check)
* [Rails cache check](#rails-cache-check)
* [Elasticsearch check](#elasticsearch-check)
* [RabbitMQ check](#rabbitmq-check)
* [HTTP check](#http-check)
* [ClickHouse check](#clickhouse-check)
## Installation
Add this line to your application's Gemfile:
```ruby
gem 'health_bit'
```
## Configuration
```ruby
# config/initializers/health_bit.rb
HealthBit.configure do |c|
# DEFAULT SETTINGS ARE SHOWN BELOW
c.success_text = '%d checks passed 🎉'
c.headers = {
'Content-Type' => 'text/plain;charset=utf-8',
'Cache-Control' => 'private,max-age=0,must-revalidate,no-store'
}
c.success_code = 200
c.fail_code = 500
c.show_backtrace = false
c.formatter = HealthBit::Formatter.new
# DEFAULT SETTINGS ARE SHOWN ABOVE
c.add('Check name') do
# Body check, should returns `true`
true
end
end
```
## Add Checks
By default, the **gem does not contain any checks**, **you should add the
necessary checks by yourself**. The check should return `false` or `nil`
to be considered unsuccessful or throw an exception, any other
values are considered satisfactory.
Example checks:
```ruby
## Successful checks
HealthBit.add('PostgreSQL') do |env|
ApplicationRecord.connection.select_value('SELECT 1') == 1
end
HealthBit.add('Custom') do |env|
next(false) if 1 != 0
true
end
## Failed checks
HealthBit.add('Database') do |env|
false
end
HealthBit.add('Docker service') do |env|
raise 'not responding'
end
# The Check can be added as an object responding to a call
# (to be able to test your check)
class Covid19Check
def self.call(env)
false
end
end
HealthBit.add('COVID-19 Checker', Covid19Check)
```
## Add a Route
Since the gem is a rack application, you must mount it to app's
routes. Below is an example for the Rails.
```ruby
# config/routes.rb
Rails.application.routes.draw do
mount HealthBit.rack => '/health'
end
```
```bash
curl --verbose http://localhost:3000/health
< HTTP/1.1 200 OK
< Content-Type: text/plain;charset=utf-8
< Cache-Control: private,max-age=0,must-revalidate,no-store
< X-Request-Id: 59a796b9-29f7-4302-b1ff-5d0b06dd6637
< X-Runtime: 0.006007
< Vary: Origin
< Transfer-Encoding: chunked
4 checks passed 🎉
```
## Password Protection
Since the gem is a common rack application, you can add any rack
middleware to it. Below is an example with HTTP-auth for the Rails.
```ruby
# config/routes.rb
Rails.application.routes.draw do
HealthBit.rack.use Rack::Auth::Basic do |username, password|
ActiveSupport::SecurityUtils.secure_compare(Digest::SHA256.hexdigest(username), Digest::SHA256.hexdigest('user')) & ActiveSupport::SecurityUtils.secure_compare(Digest::SHA256.hexdigest(password), Digest::SHA256.hexdigest('password'))
end
mount HealthBit.rack => '/health'
end
```
## Database check
```ruby
HealthBit.add('Database') do |env|
ApplicationRecord.connection.select_value('SELECT 1') == 1
end
```
## Redis check
```ruby
HealthBit.add('Redis') do |env|
Redis.current.ping == 'PONG'
end
```
## Sidekiq check
```ruby
HealthBit.add('Sidekiq') do |env|
Sidekiq.redis(&:ping) == 'PONG'
end
```
## Rails cache check
```ruby
HealthBit.add('Rails cache') do |env|
Rails.cache.write('__health_bit__', '1', expires_in: 1.second)
end
```
## Elasticsearch check
```ruby
HealthBit.add('Elasticsearch') do |env|
Elasticsearch::Client.new.ping
end
```
## RabbitMQ check
```ruby
HealthBit.add('RabbitMQ') do |env|
Bunny::Connection.connect(&:connection)
end
```
## HTTP check
```ruby
HealthBit.add('HTTP check') do |env|
Net::HTTP.new('www.example.com', 80).request_get('/').kind_of?(Net::HTTPSuccess)
end
```
## ClickHouse check
```ruby
HealthBit.add('ClickHouse') do |env|
ClickHouse.connection.ping
end
```
## Multiple endpoints
Sometimes you have to add several health check endpoints. Let's say
you have to check the docker container health and the health
of your application as a whole. Below is an example for the Rails.
```ruby
# config/initializers/health_bit.rb
DockerCheck = HealthBit.clone
AppCheck = HealthBit.clone
DockerCheck.add('Docker Health') do |env|
true
end
AppCheck.add('App Health') do |env|
ApplicationRecord.connection.select_value("SELECT 't'::boolean")
end
```
```ruby
# config/routes.rb
Rails.application.routes.draw do
mount DockerCheck.rack => '/docker'
mount AppCheck.rack => '/app'
end
```
## Custom formatter
You can easily [configure](https://github.com/shlima/health_bit/blob/master/lib/health_bit/formatter.rb) custom format of response body, headers and
http statuses.
```ruby
class JsonFormatter < HealthBit::Formatter
# @param error HealthBit::CheckError
# @param env Hash
# @param health_bit HealthBit
def format_failure(error, env, health_bit)
{ 'status': 'error' }.to_json
end
# @param error HealthBit::CheckError
# @param env Hash
# @param health_bit HealthBit
def headers_failure(error, env, health_bit)
{
'Content-Type' => 'application/json'
}
end
end
HealthBit.configure do |c|
c.formatter = JsonFormatter.new
end
```