# Goth
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Google + Auth = Goth
A simple library to generate and retrieve OAuth2 tokens for use with Google Cloud Service accounts.
## Installation
**Note:** below are instructions for using Goth v1.3+. For more information on earlier versions of Goth, [see v1.2.0 documentation on hexdocs.pm](https://hexdocs.pm/goth/1.2.0).
1. Add `:goth` to your list of dependencies in `mix.exs`.
```elixir
def deps do
[
{:goth, "~> 1.3"}
]
end
```
2. Add Goth to your supervision tree:
```elixir
defmodule MyApp.Application do
use Application
def start(_type, _args) do
credentials = "GOOGLE_APPLICATION_CREDENTIALS_JSON" |> System.fetch_env!() |> Jason.decode!()
source = {:service_account, credentials}
children = [
{Goth, name: MyApp.Goth, source: source}
]
Supervisor.start_link(children, strategy: :one_for_one)
end
end
```
If you set `GOOGLE_APPLICATION_CREDENTIALS` or `GOOGLE_APPLICATION_CREDENTIALS_JSON`, have a
`~/.config/gcloud/application_default_credentials.json` file, or deploy your application to
Google Cloud, you can omit the `:source` option:
```elixir
def start(_type, _args) do
children = [
{Goth, name: MyApp.Goth}
]
Supervisor.start_link(children, strategy: :one_for_one)
end
```
If you want to use multiple credentials, you may consider doing:
```elixir
def start(_type, _args) do
Supervisor.start_link(servers(), strategy: :one_for_one)
end
defp servers do
servers = [
{MyApp.Cred1, source1},
...
{MyApp.CredN, source2}
]
for {name, source} <- servers do
Supervisor.child_spec({Goth, name: name, source: source}, id: name)
end
end
```
3. Fetch the token:
```elixir
iex> Goth.fetch!(MyApp.Goth)
%Goth.Token{
expires: 1453356568,
token: "ya29.cALlJ4ICWRvMkYB-WsAR-CZnExE459PA7QPqKg5nei9y2T9-iqmbcgxq8XrTATNn_BPim",
type: "Bearer",
...
}
```
See `Goth.start_link/1` for more information about possible configuration options.
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## Upgrading from Goth 1.2
See [Upgrading from Goth 1.2](UPGRADE_GUIDE.md) guide for more information.
## Community resources
- [How to upload on YouTube Data API with elixir ?](https://mrdotb.com/posts/upload-on-youtube-with-elixir/)
