Add Generate A Signed JWT Token as a ruby til

README.md

@@ -10,7 +10,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 For a steady stream of TILs from a variety of rocketeers, checkout
 [til.hashrocket.com](https://til.hashrocket.com/).
 
-_763 TILs and counting..._
+_764 TILs and counting..._
 
 ---
 
@@ -601,6 +601,7 @@ _763 TILs and counting..._
 - [FactoryGirl Sequences](ruby/factory-girl-sequences.md)
 - [Fail](ruby/fail.md)
 - [Finding The Source of Ruby Methods](ruby/finding-the-source-of-ruby-methods.md)
+- [Generate A Signed JWT Token](ruby/generate-a-signed-jwt-token.md)
 - [Generate Ruby Version And Gemset Files With RVM](ruby/generate-ruby-version-and-gemset-files-with-rvm.md)
 - [Identify Outdated Gems](ruby/identify-outdated-gems.md)
 - [If You Detect None](ruby/if-you-detect-none.md)

ruby/generate-a-signed-jwt-token.md

@@ -0,0 +1,19 @@
+# Generate A Signed JWT Token
+
+The [`jwt`](https://github.com/jwt/ruby-jwt) gem is a Ruby library for
+encoding and decoding JWT tokens. You can create a signed JWT with the
+`#encode` method by specifying a secret and a hash algorithm.
+
+```ruby
+payload = { id: 1, email: 'user@example.com' }
+secret = Rails.application.credentials.secret_key_base
+
+token = JWT.encode(payload, secret, 'HS256')
+```
+
+This will create a JWT token that contains some JWT headers, application
+data, and an encrypted secret that signs the data. This can be passed to and
+from your client app as a way of identifying and authenticating a user.
+
+See the [`jwt-ruby` docs](https://github.com/jwt/ruby-jwt) or
+[jwt.io](https://jwt.io/) for more details.