Merge pull request #4539 from kumarom/registry-proxy

Add docs for registry proxy addon

docs/reusing_the_docker_daemon.md

@@ -1,5 +1,7 @@
 # Reusing the Docker daemon
 
+## Method 1: Without minikube registry addon
+
 When using a single VM of Kubernetes it's really handy to reuse the Docker daemon inside the VM; as this means you don't have to build on your host machine and push the image into a docker registry - you can just build inside the same docker daemon as minikube which speeds up local experiments.
 
 To be able to work with the docker daemon on your mac/linux host use the docker-env command in your shell:
@@ -14,6 +16,12 @@ You should now be able to use docker on the command line on your host mac/linux
 docker ps
 ```
 
+Docker may report following forbidden error if you are using http proxy and the `$(minikube ip)` is not added to `no_proxy`/`NO_PROXY`:
+
+```shell
+error during connect: Get https://192.168.39.98:2376/v1.39/containers/json: Forbidden
+```
+
 On Centos 7, docker may report the following error:
 
 ```shell
@@ -31,3 +39,43 @@ The fix is to update /etc/sysconfig/docker to ensure that minikube's environment
 ```
 
 Remember to turn off the _imagePullPolicy:Always_, as otherwise Kubernetes won't use images you built locally.
+
+## Method 2: With minikube registry addon
+
+Enable minikube registry addon and then push images directly into registry. Steps are as follows:
+
+For illustration purpose, we will assume that minikube VM has one of the ip from `192.168.39.0/24` subnet. If you have not overridden these subnets as per [networking guide](https://github.com/kubernetes/minikube/blob/master/docs/networking.md), you can find out default subnet being used by minikube for a specific OS and driver combination [here](https://github.com/kubernetes/minikube/blob/dfd9b6b83d0ca2eeab55588a16032688bc26c348/pkg/minikube/cluster/cluster.go#L408) which is subject to change. Replace `192.168.39.0/24` with appropriate values for your environment wherever applicable.
+
+Ensure that docker is configured to use `192.168.39.0/24` as insecure registry. Refer [here](https://docs.docker.com/registry/insecure/) for instructions.
+
+Ensure that `192.168.39.0/24` is enabled as insecure registry in minikube. Refer [here](https://github.com/kubernetes/minikube/blob/master/docs/insecure_registry.md) for instructions..
+
+Enable minikube registry addon:
+
+```shell
+minikube addons enable registry
+```
+
+Build docker image and tag it appropriately:
+
+```shell
+docker build --tag $(minikube ip):5000/test-img .
+```
+
+Push docker image to minikube registry:
+
+```shell
+docker push $(minikube ip):5000/test-img
+```
+
+Now run it in minikube:
+
+```shell
+kubectl run test-img --image=$(minikube ip):5000/test-img
+```
+
+Or if `192.168.39.0/24` is not enabled as insecure registry in minikube, then:
+
+```shell
+kubectl run test-img --image=localhost:5000/test-img
+```