# aws_ssm_provider

A configuration provider for Distillery which handles AWS SSM parameters.

## Usage

This package is intended to be used in conjunction with [Distillery Config Providers](https://hexdocs.pm/distillery/config/runtime.html#config-providers).
To generate the file the config provider will read, run a command similar to

```bash
aws --region us-east-1 ssm get-parameters-by-path --path "/${SECRETS_PATH}/YOUR_PROJECT/" --recursive --with-decryption --query "Parameters[]" \
    > /app/_build/prod/rel/<your_project>/config.json
```

AWS recommends the path of the parameter keys follow a pattern similar to `/environment/project/service/config_key`

For example, a typical path you might set in SSM for your elixir project would be `/production/myApp/redix/port`

### Nesting

This package supports setting application variables that are keyword lists. For example, the path `/production/myApp/myWebApp/database/connection/port` would result in a myWebApp application variable like this

```elixir
[
    database: [
        connection: [
            port: yourValue
        ]
    ]
]
```

### Type Handling

All SSM keys are returned as strings. If you want to set your value as another type, please see the supported types below.

#### Integers

To set an integer in your application config, simply end your SSM path in `/Integer`. For example, if you wanted your port to be `4000` and not `"4000"`, your SSM key would look like `/staging/myApp/port/Integer`

#### Regular Expressions

To set a regex in your application config, simply end your SSM path in `/Regex`. For example, if you wanted a fileName config to match `"2019.csv"`, your SSM key would look like `/staging/myApp/fileName/Regex`. The value you enter in SSM would be

```bash
(\\d{4}.csv)
```

Notice the parantheses and the escape character for the back slash.

#### Booleans

`"true"` and `"false"` are translated to their respective boolean values.

### System Vars

If you have a variable in your system environment that you want injected in an application configuration, simply end your path in `/FromSystem`, for example: `/staging/myApp/database/host/FromSystem`. When using the system vars, the value of your SSM parameter will be the name of the environment variable. In this case, something like `DB_HOST`.

## Installation

The package can be installed by adding `aws_ssm_provider` to your list of dependencies in `mix.exs`:

```elixir
def deps do
  [
    {:aws_ssm_provider, "~> 0.1.1"}
  ]
end
```

The docs can be found at [https://hexdocs.pm/aws_ssm_provider](https://hexdocs.pm/aws_ssm_provider).