feat(polling-registry) Add BASIC & OAuth2 client auth support for HTTP/HTTPS file loading.

[msavy]

• Add BASIC & OAuth2 client auth support for HTTP/HTTPS file loading.

• Refactor for improved extensibility, with assumption additional auth methods will be added later.

[msavy]

Example of using HTTP with BASIC auth:

  "registry": {
      "class": "io.apiman.gateway.engine.vertx.polling.URILoadingRegistry",
      "config": {
          "configUri": "https://gist.githubusercontent.com/msavy/cb245f4ed5228e8aa368a03b035f4b9b/raw/25dcc614dba43821b7623e16302b404c39bdeeca/apiman-gateway-api.json",
          "auth": "basic",
          "username": "foo",
          "password": "bar"
      }
  },

Might change the layout a bit, but you get the gist.

Example with OAuth2:

  "registry": {
      "class": "io.apiman.gateway.engine.vertx.polling.URILoadingRegistry",
      "config": {
          "configUri": "https://gist.githubusercontent.com/msavy/cb245f4ed5228e8aa368a03b035f4b9b/raw/25dcc614dba43821b7623e16302b404c39bdeeca/apiman-gateway-api.json",
          "auth": "OAuth2Client",
          "flowType": "password",
          "oauthUri": "http://localhost:8080/auth",
          "tokenPath": "/realms/apiman/protocol/openid-connect/token",
          "clientID": "apiman",
          "clientSecret": "5af5458f-0a96-4251-8f92-08ebcc3a8aa2",  
          "username": "admin",
          "password": "admin123!"
      }
  },

[msavy]

Also added:

Keycloak-specific support via pmlopes's super-awesome Vert.x OAuth2 Client. Just paste the Keycloak OIDC JSON from the "installation" section in your KC client.

  "registry": {
  	"class": "io.apiman.gateway.engine.vertx.polling.URILoadingRegistry",
  	"config": {
  		"configUri": "https://gist.githubusercontent.com/msavy/cb245f4ed5228e8aa368a03b035f4b9b/raw/25dcc614dba43821b7623e16302b404c39bdeeca/apiman-gateway-api.json",
  		"realm": "apiman",
  		"realm-public-key": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAxyG61ohrfJQKNmDA/ePZtqZVpPXjwn3k3T+iWiTvMsxW2+WlnqIEmL5qZ09DMhBH9r50WZRO2gVoCb657Er9x0vfD6GNf/47XU2y33TX8axhP+hSwkv/VViaDlu4jQrfgPWz/FXMjWIZxg1xQS+nOBF2ScCRYWNQ/ZnUNnvrq8dGC2/AlyeYcgDUOdwlJuvgkGlF0QoVPQiRPurR3RwlG+BjL8JB3hbaAZhdJqwqApmGQbcpgLj2tODnlrZnEAp5cPPU/lgqCE1OOp78BAEiE91ZLPl/+D8qDHk+Maz0Io3bkeRZMXPpvtbL3qN+3GlF8Yz264HDSsTNrH+nd19tFQIDAQAB",
  		"auth-server-url": "http://localhost:8080/auth",
  		"ssl-required": "none",
  		"resource": "apiman",
  		"credentials": {
  			"secret": "5af5458f-0a96-4251-8f92-08ebcc3a8aa2"
  		},
  		"username": "admin",
  		"password": "admin123!",
  		"auth": "KeycloakOAuth2Client",
  		"flowType": "password"
  	}
  }