Add blog post about deprecating nodes

ref #2460
https://pulp.plan.io/issues/2460

.mention-bot

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 {
     "userBlacklist": [
-        "tomjohnson1492",
+        "tomjohnson1492"
     ]
 }

_posts/2016-12-06-deprecating-nodes.md

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+---
+title: Deprecating Nodes
+author: David Davis
+tags:
+  - release
+  - platform
+  - 3.0
+---
+
+Nodes were introduced in Pulp in 2.1.0 and provided a way to keep multiple Pulp
+servers in sync. However, maintaining Nodes in Pulp meant having to maintain a
+separate codebase and given that much of the functionality of Nodes can be
+acheived by running Pulp straight out of the box, we've decided to remove Nodes
+in our next major release of Pulp 3.0. With Pulp 2.11, Nodes will be officially
+deprecated.
+
+In this blog post, I want to outline how users can sync content across Pulp
+servers without using Nodes and how tools like cron and systemd can be used to
+keep content updated across Pulp servers. I am going to illustrate a two-server
+example in which I'll call one Pulp server the parent and the other the child.
+However, this distinction is arbitrary as both servers are configured the same
+way. The child Pulp server is simply the one we want to mirror content to.
+
+Syncing Content to a Child Server
+---------------------------------
+
+Suppose I have an rpm repo called 'centos-base' on the parent Pulp server.
+First I would want to publish that repository to make it available for the
+child Pulp server to sync:
+
+    pulp-admin rpm repo publish run --repo-id centos-base
+
+This repository should then be available via http or https. You can check its
+relative url via `pulp-admin rpm repo list --repo-id centos-base --details`. In
+my case, it's at "https://example.com/pulp/repos/centos-base". Now on the child
+node, I can simply create and sync the repository:
+
+    pulp-admin rpm repo create --repo-id centos-base --feed https://example.com/pulp/repos/centos-base
+    pulp-admin rpm repo sync run --repo-id centos-base
+
+Now the centos-base repository from my parent Pulp server has been mirrored
+onto a child server.
+
+
+Automatically Updating Content
+------------------------------
+
+By using cron or a systemd timer, we can keep content on the child Pulp server
+up-to-date automatically. The pulp-admin sync command can be run automatically
+based on your needs. For example, if we want to check for new content for our
+'centos-base' repository hourly, we could create a crontab entry:
+
+    @hourly pulp-admin rpm repo sync run --repo-id centos-base