# Migration guide from 2.0.x to 2.1.0

Please note that for standard usage, when configuring MongoosePush only with environmental variables, the `config/*.exs` files are upgraded automatically and there is no action required from your end.
If your MongoosePush is using modified `config/*.exs` files, please have a closer look at the changes presented below to see if you have to adjust your custom configuration.
In such case, there could be a few changes necessary in the configuration files and a few additional, optional ones.

## Main config (`config/config.exs`)

MongoosePush supports structured logging from the 2.1.0 release. To use that feature, there is a need to change the logger configuration to use the new default.
Old logger config:

```elixir
config :logger, :console,
  format: "\n$dateT$time [$level] $metadata$levelpad$message\n",
  metadata: [:pid]
```

New logger config:
```elixir
config :logger, :console,
  format: {MongoosePush.Logger.LogFmt, :format},
  metadata: :all
```
Further notes on logging are in the [logging section](2.0.x_2.1.0.md#logging)

Additionally there are a few new defaults needed to be set up:
```elixir
config :mongoose_push, MongoosePush.Service,
  fcm: MongoosePush.Service.FCM,
  apns: MongoosePush.Service.APNS

config :mongoose_push, backend_module: MongoosePush

config :phoenix, :json_library, Jason
```

Lastly, since 2.1.0 MongoosePush uses `Phoenix` instead of `Maru` and Maru config entry can be removed.
```elixir
config :maru, :test, false
```

## Environmental configs (`config/{prod|dev|test}.exs`)

### `Phoenix` in place of `Maru`
As mentioned earlier, MongoosePush uses `Phoenix` and the config has to be updated to reflect that change.
Old `Maru` config entry:
```elixir
config :maru, MongoosePush.Router,
  versioning: [
    using: :path
  ],
  https: [
    bind_addr: {:system, :string, "PUSH_HTTPS_BIND_ADDR", "127.0.0.1"},
    port: {:system, :integer, "PUSH_HTTPS_PORT", 8443},
    keyfile: {:system, :string, "PUSH_HTTPS_KEYFILE", "priv/ssl/fake_key.pem"},
    certfile: {:system, :string, "PUSH_HTTPS_CERTFILE", "priv/ssl/fake_cert.pem"},
    cacertfile: {:system, :string, "PUSH_HTTPS_CERTFILE", "priv/ssl/fake_cert.pem"},
    acceptors: {:system, :integer, "PUSH_HTTPS_ACCEPTORS", 100},
    otp_app: :mongoose_push
  ]
```
It should be removed completely and in its place there must be the new, `Phoenix` config entry:
```elixir
config :mongoose_push, MongoosePushWeb.Endpoint,
  https: [
    ip: {
      :system,
      # Custom type parser (Phoenix needs erlang-inet-style IP address)
      {MongoosePush.Config.Utils, :parse_bind_addr, []},
      "PUSH_HTTPS_BIND_ADDR",
      {127, 0, 0, 1}
    },
    port: {:system, :integer, "PUSH_HTTPS_PORT", 8443},
    keyfile: {:system, :string, "PUSH_HTTPS_KEYFILE", "priv/ssl/fake_key.pem"},
    certfile: {:system, :string, "PUSH_HTTPS_CERTFILE", "priv/ssl/fake_cert.pem"},
    cacertfile: {:system, :string, "PUSH_HTTPS_CERTFILE", "priv/ssl/fake_cert.pem"},
    protocol_options: [
      # https://ninenines.eu/docs/en/cowboy/2.5/manual/cowboy_http/
    ],
    transport_options: [
      # https://ninenines.eu/docs/en/ranch/1.6/manual/ranch_tcp/
      # https://ninenines.eu/docs/en/ranch/1.6/manual/ranch_ssl/
      num_acceptors: {:system, :integer, "PUSH_HTTPS_ACCEPTORS", 100}
    ],
    otp_app: :mongoose_push
  ],
  debug_errors: false,
  code_reloader: false,
  check_origin: true,
  server: true
  ```
  As you can see, there is no change in the variables used to parse the options.

### Logging
Old logging entry looked like this:
```elixir
config :mongoose_push, loglevel: {:system, :atom, "PUSH_LOGLEVEL", :info}
```

New logging entry may look like the following:
```elixir
config :mongoose_push, :logging,
  level: {:system, :atom, "PUSH_LOGLEVEL", :info},
  format: {:system, :atom, "PUSH_LOGFORMAT", :json}
```

The structure changed a little and there is a new variable, `PUSH_LOGFORMAT`.
It defaults to `:json` for the `prod` environment, and to `:logfmt` for the `dev` and `test` environments.
The `logfmt` backend was changed to support structured logging.
Please note that if you had a MongoosePush node configured with a log aggregation backend it probably needs to be reconfigured to match the current format of the log messages.
You might also want to consider using the second standard, `JSON`, that MongoosePush now supports.

### OpenAPI
MongoosePush can expose OpenAPI specification if enabled. Config entry may look like this:
```elixir
config :mongoose_push,
  openapi: [
    expose_spec: {:system, :boolean, "PUSH_OPENAPI_EXPOSE_SPEC", false},
    expose_ui: {:system, :boolean, "PUSH_OPENAPI_EXPOSE_UI", false}
  ]
  ```
`PUSH_OPENAPI_EXPOSE_SPEC` enables OpenAPI endpoint support and `PUSH_OPENAPI_EXPOSE_UI` enables SwaggerUI.
Both these options are disabled by default. For more details refer to the [configuration guide](../configuration.md#general-settings).

### Elixometer
MongoosePush does not use `Elixometer` for its metrics anymore. Metrics are provided using `Telemetry` and `elixometer` config entry should be removed.
Old `elixometer` entry:
```elixir
config :elixometer,
  reporter: :exometer_report_tty,
  env: Mix.env(),
  metric_prefix: "mongoose_push"
  ```

There is no config entry necessary for `Telemetry` metrics.
To learn more about the new metrics and see how to setup default Grafana dashboards check out the [metrics guide](../metrics.md).

### API

Please note that API v2 is deprecated and will be removed in the future.
API v2 and v3 differ only by the returned status and content in case of errors, so in case you are using API v2 please consider changing to API v3.