Update readme to include kubernetes secrets (#198)

Author: remacr

README.md

@@ -9,13 +9,15 @@ Kubeless is a Kubernetes-native Serverless solution.
 Make sure you have a kubernetes endpoint running and kubeless installed. You can find the installation intructions [here](https://github.com/kubeless/kubeless#installation).
 
 Once you have Kubeless running in your cluster you can install serverless
+
 ```bash
 $ npm install serverless -g
 ```
 
 ## Try out the example
 
 Clone this repo and check the example function
+
 ```bash
 $ git clone https://github.com/serverless/serverless-kubeless
 $ cd examples/get-python
@@ -36,11 +38,13 @@ functions:
 ```
 
 Download dependencies
+
 ```bash
 $ npm install
 ```
 
 Deploy function.
+
 ```bash
 $ serverless deploy
 Serverless: Packaging service...
@@ -50,6 +54,7 @@ Serverless: Function hello successfully deployed
 ```
 
 The function will be deployed to k8s via kubeless.
+
 ```bash
 $ kubectl get function
 NAME      KIND
@@ -61,6 +66,7 @@ hello-1815473417-1ttt7   1/1       Running   0          1m
 ```
 
 Now you will be able to call the function:
+
 ```bash
 $ serverless invoke -f hello -l
 Serverless: Calling function: hello...
@@ -69,6 +75,7 @@ hello world
 ```
 
 You can also check the logs for the function:
+
 ```bash
 $ serverless logs -f hello
 172.17.0.1 - - [12/Jul/2017:09:47:18 +0000] "GET /healthz HTTP/1.1" 200 2 "" "Go-http-client/1.1" 0/118
@@ -78,6 +85,7 @@ $ serverless logs -f hello
 ```
 
 Or you can obtain the function information:
+
 ```bash
 $ serverless info
 Service Information "hello"
@@ -97,22 +105,44 @@ Dependencies:
 ```
 
 You can access the function through its HTTP interface as well using `kubectl proxy` and accessing:
+
 ```bash
 $ curl http://127.0.0.1:8001/api/v1/namespaces/default/services/hello/proxy/
 hello world
 ```
 
 If you have a change in your function and you want to redeploy it you can run:
+
 ```bash
 $ serverless deploy function -f hello
 Serverless: Redeploying hello...
 Serverless: Function hello successfully deployed
 ```
 
 Finally you can remove the function.
+
 ```bash
 $ serverless remove
 Serverless: Removing function: hello...
 Serverless: Function hello successfully deleted
 ```
 
+## Kubernetes secrets
+
+Kubernetes secret objects let you store and manage sensitive information, such as passwords, OAuth tokens, and ssh keys.
+Putting this information in a secret is safer and more flexible than putting it verbatim in a Pod definition or in a container image. To use secrets follow the next steps:
+
+1. Create a K8s secret:
+   `kubectl create secret generic secret-file --from-file=secret.txt -n namespace-name`
+
+2. Add the secret key into the provider definition in the serverless.yml file below the `secrets` key. You can specify an array of secrets and they will be mounted at root level in the pod file system using the path `/<secret-name>`:
+
+```yaml
+provider:
+  name: kubeless
+  ....
+  secrets:
+     - secret-file
+```
+
+3. Now inside your pod, you will be able to access the route `/secret-file/secret.txt`.