Loopback-next: Pass auth header from client to loopback rest-connector

[arunkumarreddygoluguri]

How to pass the Authorization header to the rest-connector for multi-tenanted systems using loopback4. Something like "Before Execute" at an application level for all the requests to rest connector.

[jannyHou]

Hi @arunkumarreddygoluguri I guess you moved the discussion from https://github.com/strongloop/loopback-connector-rest/issues/89

To parse the token from header, you can add an action in sequence to parse the access token from header.
An example is how we retrieved it in the authentication action, see https://github.com/strongloop/loopback4-example-shopping/blob/master/src/authentication-strategies/JWT.strategy.ts#L15

If you want to pass it to controller, you can leverage the dependency injection to inject the access token.

By saying

How to pass the Authorization header to the rest-connector

do you mean pass it as a configuration when initialize the connector or pass it into a connector function?

[arunkumarreddygoluguri]

@jannyHou Thanks for the reply, I am building a custom auth token in sequnce.ts by looking at the input parameters from the client app, now this custom auth token need to be passed to all the API requests for a particular rest connector

[marioestradarosa]

Hi @arunkumarreddygoluguri ,

I had to do something similar with other parameters for the rest-connector, this is a simple solution, but it worked for me.

Once you get your custom auth token you can register in the context in the sequence.ts file as you stated.

      context.bind('savedCustomToken').to(yourCustomToken);  

Then in the controller(s) you inject it like so:

constructor (
      @inject('savedCustomToken') public token: string,
...

Now here comes the tricky part where this solutions falls into the simple category. In your custom methods, you need to add the token as argument, so all service method invocation carries out this parameter. (ie: yourMethod(arg1: string) now should become yourMethod(arg1: string, token: string) where token is an arbitrary name. _(service proxy interface will also have to change to have this parameter)._

Note: You can also create an interceptor to intercept myCustomMethod invocation and add this last parameter automatically.

In your template for the rest connector you will have something like this:

{
      "template": {
        "method": "POST",
        "url": "http://sampleURL/",
        "headers": {
          "Authorization": "Bearer {token}",
          "cache-control": "no-cache",
           "Content-Type": "application/json"
        },
        "body": "{dummyVar1}"
      },
      "functions": {
        "myCustomMethod": [
          "dummyVar1",
          "token"
        ]
      }
    }

[jannyHou]

I am closing this issue since the answer is provided. Feel free to reopen it if you still have questions.