Adds redis tutorial with systemctl service check, 2 example use cases (#525)

* Adds redis tutorial with systemctl service check; add 2 example use cases.
- Closes #519

Signed-off-by: Michael Vincerra <michael.vincerra@intel.com>

Refine intro and add development examples.

Signed-off-by: Michael Vincerra <michael.vincerra@intel.com>

Revise wording intro; add hyperlinks in Example 2.

Signed-off-by: Michael Vincerra <michael.vincerra@intel.com>

Correct description of client libraries.

Signed-off-by: Michael Vincerra <michael.vincerra@intel.com>

Correct spacing; add note to define syntax behavior.

Signed-off-by: Michael Vincerra <michael.vincerra@intel.com>

Respond to reviewer's feedback. Revise wording. Add docker command.

Signed-off-by: Michael Vincerra <michael.vincerra@intel.com>

Apply wording revisions for clarity.

Signed-off-by: Michael Vincerra <michael.vincerra@intel.com>

Edit for squash.

Signed-off-by: Michael Vincerra <michael.vincerra@intel.com>

* Resolve build error to avoid duplicate ref's.

Signed-off-by: Michael Vincerra <michael.vincerra@intel.com>

source/clear-linux/tutorials/redis.rst

@@ -0,0 +1,215 @@
+.. _redis:
+
+Run Redis on |CL-ATTR|
+######################
+
+Redis is an in-memory key:value store designed for quick lookups, accessible
+over the network. In this tutorial, you'll install redis and launch a
+redis-server on |CL|, plus learn a few basic redis commands. We also invite
+you to pull our `Clear Linux Redis instance`_ on dockerhub\* for application
+or infrastructure development.
+
+While the `redis data structure store`_ can serve as a NoSQL database for a Web application, it's also easy to integrate in an existing stack. For example, you could use the Redis caching layer for real-time responses on a leaderboard in a gaming app. Redis offers many client libraries with language-specific bindings for Python, Perl, Ruby, and more.
+
+.. contents::
+   :local:
+   :depth: 1
+
+Prerequisites
+*************
+* Install the `redis-native` bundle in |CL|
+* Install the `containers-basic` bundle in |CL| (only required in Example 2)
+
+Install the redis bundle
+************************
+
+In |CL|, find redis in the `redis-native` bundle.
+
+#. Open a Terminal and login as an administrative user.
+
+#. Add :file:`redis-native`.
+
+.. code-block:: bash
+
+   sudo swupd bundle-add redis-native
+
+.. note::
+
+   If the bundle already exists, no action is required.
+
+Start the redis-server
+**********************
+
+A `systemd` service unit is available to control the redis server.
+By default, redis runs on port 6379.
+
+#. Start the service.
+
+   .. code-block:: bash
+
+      systemctl start redis
+
+   .. note::
+
+      To stop redis run :command:`systemctl stop redis`.
+
+#. Assure the service is running.
+
+   .. code-block:: bash
+
+      systemctl status redis
+
+#. Verify the redis-server sends a reply.
+
+   .. code-block:: bash
+
+      redis-cli ping
+
+   .. note::
+
+      Expected output: `PONG`.
+
+#. Optional: If you wish to apply advanced configuration, copy the
+   `redis.conf` into /etc/ directory.
+
+   .. code-block:: bash
+
+      sudo cp /usr/share/defaults/etc/redis.conf /etc/
+
+The redis-server is now ready to use on |CL|. Try some examples below.
+
+Example 1: Use the redis-cli and try commands
+*********************************************
+
+One advantage of redis over other NoSQL databases is that developers can
+easily access data structures like lists, sets, sorted sets, strings, and
+hashes using collection operations commands similar to those found in many
+programming languages. These exercises are inspired by `try redis io`_.
+
+After your `redis-server` is running, try some basic commands.
+
+#. Enter the `redis-cli`. It provides syntax suggestions as you type.
+
+   .. code-block:: bash
+
+      redis-cli
+
+#. SET key to hold string value. In the set create connections and increment.
+
+   .. code-block:: bash
+
+      SET server:name "clearlinux"
+
+   .. code-block:: bash
+
+      MGET server:name
+
+   .. note::
+      If the key does not exist or hold a key value, `nil` is returned.
+
+   .. code-block:: bash
+
+      SET connections 100
+
+   .. code-block:: bash
+
+      INCR connections
+
+   .. code-block:: bash
+
+      INCR connections
+
+   .. code-block:: bash
+
+      DEL connections
+
+#. Create a `friends` list and insert new values at the end of the list.
+
+   .. code-block:: bash
+
+      RPUSH friends "Deb"
+
+   .. code-block:: bash
+
+      RPUSH friends "David"
+
+   .. code-block:: bash
+
+      RPUSH friends "Mary"
+
+#. Modify `friends` list, using a common slice method with a 0-index.
+
+   .. code-block:: bash
+
+      LRANGE friends 0 1
+
+   .. code-block:: bash
+
+      LLEN friends
+
+   .. code-block:: bash
+
+      LPOP friends
+
+   .. code-block:: bash
+
+      RPOP friends
+
+   .. code-block:: bash
+
+      LLEN friends
+
+#. Consider using a hash, a very useful data type, which maps string fields
+   and string values, offering multiple lookup methods.
+
+   Enter many user key:values with `HMSET`. Then try `HGET` and `HGETALL`.
+
+   .. code-block:: bash
+
+      HMSET user:1000 name "Robert Noyce" password "SuperEngi9eer" email "robert.noyce@intel.com"
+
+   .. code-block:: bash
+
+      HGET user:1000 name
+
+   .. code-block:: bash
+
+      HGET user:1000 email
+
+   .. code-block:: bash
+
+      HGETALL user:1000
+
+
+Example 2: Run the |CL| redis docker image
+******************************************
+
+We also provide a `Clear Linux Redis instance`_, which is
+updated continuously and maintained by |CL| development.
+
+.. code-block:: bash
+
+   sudo swupd bundle-add containers-basic
+
+.. code-block:: bash
+
+   sudo systemctl start docker
+
+.. code-block:: bash
+
+   sudo -E docker pull clearlinux/redis
+
+Next Steps
+**********
+
+* Follow the `redis quickstart tutorial`_ to expand potential uses.
+
+* Learn to :ref:`docker`.
+
+.. _try redis io: https://try.redis.io/
+
+.. _Clear Linux Redis instance: https://hub.docker.com/r/clearlinux/redis
+
+.. _redis data structure store: https://redis.io/
+
+.. _redis quickstart tutorial: https://redis.io/topics/quickstart

source/clear-linux/tutorials/tutorials.rst

@@ -27,3 +27,4 @@ Explore our tutorials to discover what you can do with |CL|!
    yubikey-u2f
    nvidia
    dars
+   redis