Updating readmes for rolldice and add app deploy samples.

Author: jeroenterheerdt

samples/features/sql-big-data-cluster/app-deploy/RollDice/README.md

@@ -57,7 +57,7 @@ To run this sample, you need the following prerequisites.
     Once the app is listed as `Ready` you can continue to the next step.
 5. Test the app by running the following command:
     ```bash
-    mssqlctl app run -n roll-dice -v [version] --input x=[number of dice to roll]
+    mssqlctl app run -n roll-dice -v [version] --input x=3
     ```
     You should get output like the example for three dice below. The results of the dice rolled are in the `result` data frame:
     ```json

samples/features/sql-big-data-cluster/app-deploy/addpy/README.md

@@ -0,0 +1,111 @@
+# Running a Python script in SQL Server big data cluster
+
+### Contents
+
+[About this sample](#about-this-sample)<br/>
+[Before you begin](#before-you-begin)<br/>
+[Run this sample](#run-this-sample)<br/>
+[Sample details](#sample-details)<br/>
+[Related links](#related-links)<br/>
+
+<a name=about-this-sample></a>
+
+## About this sample
+
+This is a sample [Python](https://www.python.org/) app, which shows how to run a Python script in SQL Server big data cluster. This sample creates an app that adds two whole numbers and returns the result. The code for this sample is in [add.py](add.py) The inputs and outputs are shown below.
+
+### Inputs
+|Parameter|Description|
+|-|-|
+|`x`|The first whole number to add|
+|`y`|The second whole number to add|
+
+### Outputs
+|Parameter|Description|
+|-|-|
+|`result`|The result of adding `x` and `y`|
+
+
+<a name=before-you-begin></a>
+
+## Before you begin
+
+To run this sample, you need the following prerequisites.
+
+**Software prerequisites:**
+
+1. SQL Server big data cluster CTP 2.3 or later.
+2. `mssqlctl`. Refer to [installing mssqlctl](https://docs.microsoft.com/en-us/sql/big-data-cluster/deploy-install-mssqlctl?view=sqlallproducts-allversions) document on setting up the `mssqlctl` and connecting to a SQL Server 2019 big data cluster.
+
+<a name=run-this-sample></a>
+
+## Run this sample
+
+1. Clone or download this sample on your computer.
+2. Log in to the SQL Server big data cluster using the command below using the IP address of the `endpoint-service-proxy` in your cluster. If you are not familiar with `mssqltctl` you can refer to the [documentation](https://docs.microsoft.com/en-us/sql/big-data-cluster/big-data-cluster-create-apps?view=sqlallproducts-allversions) and then return to this sample.
+
+    ```bash
+    mssqlctl login -e https://<ip-address-of-endpoint-service-proxy>:30777 -u <user-name> -p <password>
+    ```
+3. Deploy the application by running the following command, specifying the folder where your `spec.yaml` and `add.py` files are located:
+    ```bash
+    mssqlctl app create --spec ./addpy
+    ```
+4. Check the deployment by running the following command:
+    ```bash
+    mssqlctl app list -n addpy -v [version]
+    ```
+    Once the app is listed as `Ready` you can continue to the next step.
+5. Test the app by running the following command:
+    ```bash
+    mssqlctl app run -n addpy -v [version] --input x=3,y=5
+    ```
+    You should get output like the example below. The result of adding 3+5 are returned as `result`.
+    ```json
+    {
+      "changedFiles": [],
+      "consoleOutput": "",
+      "errorMessage": "",
+      "outputFiles": {},
+      "outputParameters": {
+        "result": 8
+      },
+      "success": true
+    }
+    ```
+6. You can clean up the sample by running the following commands:
+    ```bash
+    # delete app
+    mssqlctl app delete --name addpy --version [version]
+    ```
+
+<a name=sample-details></a>
+
+## Sample details
+
+Please refer to [add.py](add.py) for the code for this sample.
+
+### Spec file
+Here is the spec file for this application. As you can see the sample uses the `Python` runtime and calls the `add` method in the `add.py` file, accepting two integer inputs named `x` and `y` and returning an integer output named `result`.
+
+```yaml
+name: addpy
+version: v1
+runtime: Python
+src: ./add.py
+entrypoint: add
+replicas: 1
+poolsize: 1
+inputs:
+  x: int
+  y: int
+output:
+  result: int
+```
+
+<a name=related-links></a>
+
+## Related Links
+For more information, see these articles:
+
+[How to deploy and app on SQL Server 2019 big data cluster (preview)](https://docs.microsoft.com/en-us/sql/big-data-cluster/big-data-cluster-create-apps?view=sqlallproducts-allversions)