Fix README.md

Author: mqasimsarfraz

README.md

@@ -18,12 +18,13 @@ The proxy is packaged in a docker container and can be configured with following
 | Environment Variable                | Description                                    | Status                            | Default    |
 | :---------------------------------: | :--------------------------------------------: | :-------------------------------: | :--------: |
 | `AWS_REGION`                        | AWS Region for AWS ECR                         | Required                          |            |
-| `AWS_ACCESS_KEY_ID`                 | AWS Account Access ID                          | Required                          |            |
-| `AWS_SECRET_ACCESS_KEY`             | AWS Account Secret Key                         | Required                          |            |
-| `RESOLVER`                          | DNS server to used by proxy                    | Required                          |            |
+| `AWS_ACCESS_KEY_ID`                 | AWS Account Access Key ID                      | Required                          |            |
+| `AWS_SECRET_ACCESS_KEY`             | AWS Account Secret Access Key                  | Required                          |            |
+| `UPSTREAM`                          | URL for AWS ECR                                | Required                          |            |
+| `RESOLVER`                          | DNS server to be used by proxy                 | Required                          |            |
 | `PORT`                              | Port on which proxy listens                    | Required                          |            |
 | `CACHE_MAX_SIZE`                    | Maximum size for cache volume                  | Optional                          |  `75g`     |
-| `CACHE_KEY`                         | Key to be used for images content/blobs        | Optional                          |  `$uri`    |
+| `CACHE_KEY`                         | Cache key used for the content by nginx        | Optional                          |  `$uri`    |
 | `ENABLE_SSL`                        | Used to enable SSL/TLS for proxy               | Optional                          | `false`    |
 | `REGISTRY_HTTP_TLS_KEY`             | Path to TLS key in the container               | Required with TLS                 |            |
 | `REGISTRY_HTTP_TLS_CERTIFICATE`     | Path to TLS cert in the container              | Required with TLS                 |            |
@@ -51,13 +52,13 @@ docker run --rm --name docker-registry-proxy --net=host \
 If you ran this command on "registry-proxy.example.com" you can now get your images using `docker pull registry-proxy.example.com:5000/repo/image`.
 
 ### Deploying the proxy
-Modify the ansible role variables according to your need and run the playbook as follow:
+Modify the ansible role [variables](https://github.com/eSailors/aws-ecr-http-proxy/tree/master/roles/docker-registry-proxy/defaults) according to your need and run the playbook as follow:
 ```sh
 ansible-playbook -i hosts playbook-docker-registry-proxy.yaml
 ```
-In case you want to enable SSL/TLS please replace the SSL certificates with the valid ones in `roles/docker-registry-proxy/files/*.pem`
+In case you want to enable SSL/TLS please replace the SSL certificates with the valid ones in [roles/docker-registry-proxy/files/*.pem](https://github.com/eSailors/aws-ecr-http-proxy/tree/master/roles/docker-registry-proxy/files)
 
 ### Note on SSL/TLS
 The proxy is using `HTTP` (plain text) as default protocol for now. So in order to avoid docker client complaining either:
  - (**Recommended**) Enable SSL/TLS using `ENABLE_SSL` configuration. For that you will have to mount your **valid** certificate/key in the container and pass the paths using  `REGISTRY_HTTP_TLS_*` variables.
- - Mark the registry host as insecure in your [deamon config](https://docs.docker.com/registry/insecure/).
+ - Mark the registry host as insecure in your client [deamon config](https://docs.docker.com/registry/insecure/).