blazer

# Blazer

Explore your data with SQL. Easily create charts and dashboards, and share them with your team.

[Try it out](https://blazer.dokkuapp.com)

[![Screenshot](https://blazer.dokkuapp.com/assets/blazer-176c595c.png)](https://blazer.dokkuapp.com)

Blazer is also available as a [Docker image](https://github.com/ankane/blazer-docker).

:tangerine: Battle-tested at [Instacart](https://www.instacart.com/opensource)

[![Build Status](https://github.com/ankane/blazer/actions/workflows/build.yml/badge.svg)](https://github.com/ankane/blazer/actions)

## Features

- **Multiple data sources** - PostgreSQL, MySQL, Redshift, and [many more](#full-list)
- **Variables** - run the same queries with different values
- **Checks & alerts** - get emailed when bad data appears
- **Audits** - all queries are tracked
- **Security** - works with your authentication system

## Docs

- [Installation](#installation)
- [Queries](#queries)
- [Charts](#charts)
- [Dashboards](#dashboards)
- [Checks](#checks)
- [Cohorts](#cohorts)
- [Anomaly Detection](#anomaly-detection)
- [Forecasting](#forecasting)
- [Uploads](#uploads)
- [Data Sources](#data-sources)
- [Query Permissions](#query-permissions)

## Installation

Add this line to your application’s Gemfile:

```ruby
gem "blazer"
```

Run:

```sh
rails generate blazer:install
rails db:migrate
```

And mount the dashboard in your `config/routes.rb`:

```ruby
mount Blazer::Engine, at: "blazer"
```

For production, specify your database:

```ruby
ENV["BLAZER_DATABASE_URL"] = "postgres://user:password@hostname:5432/database"
```

When possible, Blazer tries to protect against queries which modify data by running each query in a transaction and rolling it back, but a safer approach is to use a read-only user. [See how to create one](#permissions).

#### Checks (optional)

Be sure to set a host in `config/environments/production.rb` for emails to work.

```ruby
config.action_mailer.default_url_options = {host: "blazer.dokkuapp.com"}
```

Schedule checks to run (with cron, Solid Queue, [Heroku Scheduler](https://elements.heroku.com/addons/scheduler), etc). The default options are every 5 minutes, 1 hour, or 1 day, which you can customize. For each of these options, set up a task to run.

```sh
rake blazer:run_checks SCHEDULE="5 minutes"
rake blazer:run_checks SCHEDULE="1 hour"
rake blazer:run_checks SCHEDULE="1 day"
```

You can also set up failing checks to be sent once a day (or whatever you prefer).

```sh
rake blazer:send_failing_checks
```

Here’s what it looks like with cron.

```
*/5 * * * * rake blazer:run_checks SCHEDULE="5 minutes"
0   * * * * rake blazer:run_checks SCHEDULE="1 hour"
30  7 * * * rake blazer:run_checks SCHEDULE="1 day"
0   8 * * * rake blazer:send_failing_checks
```

For Solid Queue, update `config/recurring.yml`.

```yml
production:
  blazer_run_checks_5_minutes:
    command: "Blazer.run_checks(schedule: '5 minutes')"
    schedule: every 5 minutes
  blazer_run_checks_1_hour:
    command: "Blazer.run_chec