update ssl redirect documentation (kubernetes-sigs#2274)

Author: kishorj

docs/guide/tasks/ssl_redirect.md

@@ -1,6 +1,6 @@
 # Redirect Traffic from HTTP to HTTPS
 
-We'll use the [`alb.ingress.kubernetes.io/actions.${action-name}`](../ingress/annotations.md#actions) annotation to setup an ingress to redirect http traffic into https
+You can use the [`alb.ingress.kubernetes.io/ssl-redirect`](../ingress/annotations.md#ssl-redirect) annotation to setup an ingress to redirect http traffic to https
 
 
 ## Example Ingress Manifest
@@ -14,20 +14,18 @@ metadata:
     kubernetes.io/ingress.class: alb
     alb.ingress.kubernetes.io/certificate-arn: arn:aws:acm:us-west-2:xxxx:certificate/xxxxxx
     alb.ingress.kubernetes.io/listen-ports: '[{"HTTP": 80}, {"HTTPS":443}]'
-    alb.ingress.kubernetes.io/actions.ssl-redirect: '{"Type": "redirect", "RedirectConfig": { "Protocol": "HTTPS", "Port": "443", "StatusCode": "HTTP_301"}}'
+    alb.ingress.kubernetes.io/ssl-redirect: '443'
 spec:
   rules:
     - http:
         paths:
-         - path: /*
-           backend:
-             serviceName: ssl-redirect
-             servicePort: use-annotation
          - path: /users/*
+           pathType: ImplementationSpecific
            backend:
              serviceName: user-service
              servicePort: 80
          - path: /*
+           pathType: ImplementationSpecific
            backend:
              serviceName: default-service
              servicePort: 80
@@ -36,11 +34,9 @@ spec:
 !!!note
     - `alb.ingress.kubernetes.io/listen-ports` annotation must at least include [{"HTTP": 80}, {"HTTPS":443}] to listen on 80 and 443.
     - `alb.ingress.kubernetes.io/certificate-arn` annotation must be set to allow listen for HTTPS traffic
-    - the `ssl-redirect` action must be be first rule(which will be evaluated first by ALB)
+    - the ssl-redirect port must appear in the listen-port annotation, and must be an HTTPS port
 
 ## How it works
-By default, all rules specified in ingress spec will be applied to all listeners(one listener per port) on ALB.
-
-If there is an redirection rule, the AWS Load Balancer controller will check it against every listener(port) to see whether it will introduce infinite redirection loop, and **will ignore that rule for specific listener.**
+If you enable SSL redirection, the controller configures each HTTP listener with a default action to redirect to HTTPS. The controller does not add any other rules to the HTTP listener.
 
-So for our above example, the rule by `ssl-redirect` will only been applied to http(80) listener.
+For the above example, the HTTP listener on port 80 will have a single default rule to redirect traffic to HTTPS on port 443.