<p align="center">
<img src="on-maintenance.png" width="424" height="155">
</p>
# Plug.OnMaintenance
[](https://travis-ci.org/wnuqui/on_maintenance)
[](http://inch-ci.org/github/wnuqui/on_maintenance)
_Enable maintenance mode for your Plug based Elixir applications._
**Plug.OnMaintenance**, an Elixir Plug, is used to disable access to your application for some length of time. Putting application in maintenance mode can be done programmatically or via mix tasks.
## Contents
- [Installation](#installation)
- [Setup](#setup)
- ["retry-after" response header](#retry-after-response-header)
- [Example 503 responses (default)](#example-responses)
- [Custom 503 Message](#custom-503-message)
## Installation
For whatever reason, you want your Plug based Elixir application to be in maintenance mode for some length of time. `Plug.OnMaintenance` is what you need.
Add `on_maitnenance` to your project dependencies in mix.exs:
```exs
defp deps do
[
...
{:on_maintenance, "~> 0.5"}
]
end
```
and do
```bash
mix deps.get
```
In case of error, you may want to do
```bash
mix deps.update --all
```
## Setup
Now that you have `on_maintenance` as your dependency, plug `Plug.OnMaintenance` in your `router.ex`. Let us say we have a Phoenix application.
```elixir
pipeline :api do
plug Plug.OnMaintenance
# ...
end
```
Then run this mix task
```bash
mix maintenance.init_config_store # creates sqlite db and add initial state of application (which is "not in maintenance mode")
```
Then run the application
```bash
mix phoenix.server # just in local
```
You can enable/disable maintenance mode for your application via mix tasks below
```bash
mix maintenance.enable
mix maintenance.disable
```
Or programmatically using these convenience methods below
```elixir
import Plug.OnMaintenance.Util
on_maintenance?() # will check if application is in maintenance mode
enable_maintenance() # put application in maintenance mode
disable_maintenance() # disable maintenance mode
```
## **retry-after** response header
`503` response code should have a `retry-after` [header](https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html).
You can enable maintenance mode for your application and can
specify how long it would take via `--retry-after` option!
```bash
mix maintenance.enable --retry-after=300 # application will be on maintenance for 5 minutes.
```
## Example 503 responses (default)
When in maintenance mode, your application will respond 503 to all http requests. The default message is _"application on scheduled maintenance."_. Examples:
### text/html response
```html
<html>
<body>Application on scheduled maintenance.</body>
</html>
```
### application/json response
```json
{"message": "Application on scheduled maintenance."}
```
### text/plain response
```text
Application on scheduled maintenance.
```
## Custom 503 Message
Default message can be updated via `config.exs`
```elixir
use Mix.Config
# ...
config :on_maintenance,
message: "Service is currently in maintenance mode. Give us few minutes. Thanks!"
```
