[LIVY-376][DOCS] Move Examples from README to website and update Doc links
[LIVY-376](https://issues.cloudera.org/browse/LIVY-376)
Added Examples page and nav links for Docs
This PR is a pair with https://github.com/apache/incubator-livy/pull/21
Author: Alex Bozarth <ajbozart@us.ibm.com>
Closes #5 from ajbozarth/docs.
diff --git a/site/_data/navigation.yml b/site/_data/navigation.yml
index c736876..cbac78a 100644
--- a/site/_data/navigation.yml
+++ b/site/_data/navigation.yml
@@ -18,8 +18,14 @@
- title: Get Started
url: /get-started
-- title: API Docs
- url: https://github.com/apache/incubator-livy#rest-api
+- title: Documentation
+ subcategories:
+ - title: REST API
+ url: https://github.com/apache/incubator-livy/blob/master/docs/rest-api.md#rest-api
+ - title: Programmatic API
+ url: https://github.com/apache/incubator-livy/blob/master/docs/programmatic-api.md#using-the-programmatic-api
+ - title: Examples
+ url: /examples
- title: Community
subcategories:
diff --git a/site/examples.md b/site/examples.md
new file mode 100644
index 0000000..556a5ac
--- /dev/null
+++ b/site/examples.md
@@ -0,0 +1,207 @@
+---
+layout: page
+title: Livy - Examples
+tagline: Examples
+---
+<!--
+{% comment %}
+Licensed to the Apache Software Foundation (ASF) under one or more
+contributor license agreements. See the NOTICE file distributed with
+this work for additional information regarding copyright ownership.
+The ASF licenses this file to you under the Apache License, Version 2.0
+(the "License"); you may not use this file except in compliance with
+the License. You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+{% endcomment %}
+-->
+
+{% include JB/setup %}
+
+# Apache Livy Examples
+
+## Spark Example
+
+Here's a step-by-step example of interacting with Livy in Python with the
+[Requests](http://docs.python-requests.org/en/latest/) library. By default Livy runs on port 8998 (which can be changed
+with the ``livy.server.port`` config option). We’ll start off with a Spark session that takes Scala code:
+
+```shell
+sudo pip install requests
+```
+
+```python
+import json, pprint, requests, textwrap
+host = 'http://localhost:8998'
+data = {'kind': 'spark'}
+headers = {'Content-Type': 'application/json'}
+r = requests.post(host + '/sessions', data=json.dumps(data), headers=headers)
+r.json()
+
+{u'state': u'starting', u'id': 0, u'kind': u'spark'}
+```
+
+Once the session has completed starting up, it transitions to the idle state:
+
+```python
+session_url = host + r.headers['location']
+r = requests.get(session_url, headers=headers)
+r.json()
+
+{u'state': u'idle', u'id': 0, u'kind': u'spark'}
+```
+
+Now we can execute Scala by passing in a simple JSON command:
+
+```python
+statements_url = session_url + '/statements'
+data = {'code': '1 + 1'}
+r = requests.post(statements_url, data=json.dumps(data), headers=headers)
+r.json()
+
+{u'output': None, u'state': u'running', u'id': 0}
+```
+
+If a statement takes longer than a few milliseconds to execute, Livy returns
+early and provides a statement URL that can be polled until it is complete:
+
+```python
+statement_url = host + r.headers['location']
+r = requests.get(statement_url, headers=headers)
+pprint.pprint(r.json())
+
+{u'id': 0,
+ u'output': {u'data': {u'text/plain': u'res0: Int = 2'},
+ u'execution_count': 0,
+ u'status': u'ok'},
+ u'state': u'available'}
+```
+
+That was a pretty simple example. More interesting is using Spark to estimate
+Pi. This is from the [Spark Examples](https://spark.apache.org/examples.html):
+
+```python
+data = {
+ 'code': textwrap.dedent("""
+ val NUM_SAMPLES = 100000;
+ val count = sc.parallelize(1 to NUM_SAMPLES).map { i =>
+ val x = Math.random();
+ val y = Math.random();
+ if (x*x + y*y < 1) 1 else 0
+ }.reduce(_ + _);
+ println(\"Pi is roughly \" + 4.0 * count / NUM_SAMPLES)
+ """)
+}
+
+r = requests.post(statements_url, data=json.dumps(data), headers=headers)
+pprint.pprint(r.json())
+
+statement_url = host + r.headers['location']
+r = requests.get(statement_url, headers=headers)
+pprint.pprint(r.json())
+
+{u'id': 1,
+ u'output': {u'data': {u'text/plain': u'Pi is roughly 3.14004\nNUM_SAMPLES: Int = 100000\ncount: Int = 78501'},
+ u'execution_count': 1,
+ u'status': u'ok'},
+ u'state': u'available'}
+```
+
+Finally, close the session:
+
+```python
+session_url = 'http://localhost:8998/sessions/0'
+requests.delete(session_url, headers=headers)
+
+<Response [204]>
+```
+
+### PySpark Example
+
+PySpark has the same API, just with a different initial request:
+
+```python
+data = {'kind': 'pyspark'}
+r = requests.post(host + '/sessions', data=json.dumps(data), headers=headers)
+r.json()
+
+{u'id': 1, u'state': u'idle'}
+```
+
+The Pi example from before then can be run as:
+
+```python
+data = {
+ 'code': textwrap.dedent("""
+ import random
+ NUM_SAMPLES = 100000
+ def sample(p):
+ x, y = random.random(), random.random()
+ return 1 if x*x + y*y < 1 else 0
+
+ count = sc.parallelize(xrange(0, NUM_SAMPLES)).map(sample).reduce(lambda a, b: a + b)
+ print "Pi is roughly %f" % (4.0 * count / NUM_SAMPLES)
+ """)
+}
+
+r = requests.post(statements_url, data=json.dumps(data), headers=headers)
+pprint.pprint(r.json())
+
+{u'id': 12,
+u'output': {u'data': {u'text/plain': u'Pi is roughly 3.136000'},
+ u'execution_count': 12,
+ u'status': u'ok'},
+u'state': u'running'}
+```
+
+### SparkR Example
+
+SparkR has the same API:
+
+```python
+data = {'kind': 'sparkr'}
+r = requests.post(host + '/sessions', data=json.dumps(data), headers=headers)
+r.json()
+
+{u'id': 1, u'state': u'idle'}
+```
+
+The Pi example from before then can be run as:
+
+```python
+data = {
+ 'code': textwrap.dedent("""
+ n <- 100000
+ piFunc <- function(elem) {
+ rands <- runif(n = 2, min = -1, max = 1)
+ val <- ifelse((rands[1]^2 + rands[2]^2) < 1, 1.0, 0.0)
+ val
+ }
+ piFuncVec <- function(elems) {
+ message(length(elems))
+ rands1 <- runif(n = length(elems), min = -1, max = 1)
+ rands2 <- runif(n = length(elems), min = -1, max = 1)
+ val <- ifelse((rands1^2 + rands2^2) < 1, 1.0, 0.0)
+ sum(val)
+ }
+ rdd <- parallelize(sc, 1:n, slices)
+ count <- reduce(lapplyPartition(rdd, piFuncVec), sum)
+ cat("Pi is roughly", 4.0 * count / n, "\n")
+ """)
+}
+
+r = requests.post(statements_url, data=json.dumps(data), headers=headers)
+pprint.pprint(r.json())
+
+{u'id': 12,
+ u'output': {u'data': {u'text/plain': u'Pi is roughly 3.136000'},
+ u'execution_count': 12,
+ u'status': u'ok'},
+ u'state': u'running'}
+```
