This repository includes the necessary files to package and deploy Wordpress, an open source content management system, into on-prem, public or private cloud environments using Gravity.
This manifest uses the Open Elastic Block Store OpenEBS built into Gravity 7.X.
- A x86_64 Linux machine or a VM for building a Cluster Image that is running one of the supported Linux distributions.
- Docker version 17 or newer. Run
docker infobefore continuing to make sure you have Docker up and running. We recommend following instructions on installing Docker CE from Docker.com - You must be a member of the
dockergroup. Rungroupscommand to make suredockergroup is listed. If not, you can add yourself to the "docker" group viasudo usermod -aG docker $USER - You must have
gitinstalled to clone the example application repo. - At least one Linux node. . The nodes in a target cluster must have at least 2GB of RAM and 40GB of free disk space. They must not have Docker.
- You must have
sudoprivileges on all nodes.
Start by downloading Gravity and unpacking the archive. You should see the following files:
$ ls -l
-rwxr-xr-x 1 user user 108093824 Apr 22 11:43 gravity
-rwxr-xr-x 1 user user 137 Apr 22 11:43 install.sh
-rw-r--r-- 1 user user 11357 Apr 22 11:43 LICENSE
-rw-r--r-- 1 user user 2880 Apr 22 11:43 README.md
-rwxr-xr-x 1 user user 84764672 Apr 22 11:43 tele
-rwxr-xr-x 1 user user 32488888 Apr 22 11:43 tsh
-rw-r--r-- 1 user user 6 Apr 22 11:43 VERSION
Execute install.sh to copy tele and tsh binaries to
/usr/local/bin/. Then you can type tele version to confirm that
everything works:
$ tele version
Edition: open-source
Version: 7.0.1
Git Commit: af393fcddf8c675f00cf322ec054125d5e239727
Helm Version: v2.15
Clone the sample Git repository which contains the Kubernetes resources for Wordpress, which we are using in this tutorial as a sample application:
$ git clone https://github.com/gravitational/gravity.git
$ cd gravity/examples
Making Wordpress run on Kubernetes is easy. The examples repository you have cloned above includes the YAML definitions of Kubernetes objects. We'll use a Helm chart for this:
$ tree wordpress/resources/charts/wordpress/
wordpress/resources/charts/wordpress/
├── Chart.yaml
├── templates
│ ├── _helpers.tpl
│ ├── mysql-deployment.yaml
│ ├── secret.yaml
│ └── wordpress-deployment.yaml
└── values.yaml
The values.yaml specifies several important values including
- Using OpenEBS for storage
- Size of the Persistent Storage for Wordpress and MySQL
- Password for MySQL db. You are welcome to modify this file and you can use --set and --values in the tele build process to replace these values. In this tutorial, we are packaging a single Helm chart but it is possible to have several of them packaged into a single Cluster Image.
Let's build the cluster image which will consist of a Kubernetes cluster with Wordpress pre-installed inside:
$ tele build -o wordpress.tar wordpress/resources/app.yaml
Mon Apr 27 00:49:02 UTC Building cluster image wordpress 0.0.1
Mon Apr 27 00:49:02 UTC Selecting base image version
Will use base image version 7.0.4
Mon Apr 27 00:49:02 UTC Downloading dependencies from s3://hub.gravitational.io
Still downloading dependencies from s3://hub.gravitational.io (10 seconds elapsed)
Still downloading dependencies from s3://hub.gravitational.io (20 seconds elapsed)
Mon Apr 27 00:50:31 UTC Embedding application container images
Pulling remote image quay.io/gravitational/debian-tall:0.0.1
Pulling remote image quay.io/gravitational/debian-tall:stretch
Pulling remote image quay.io/gravitational/provisioner:ci.82
Pulling remote image quay.io/gravitational/debian-tall:buster
Using local image mysql:5.6
Using local image wordpress:4.8-apache
Vendored image gravitational/debian-tall:0.0.1
Vendored image gravitational/debian-tall:stretch
Vendored image gravitational/debian-tall:buster
Vendored image gravitational/provisioner:ci.82
Vendored image mysql:5.6
Vendored image wordpress:4.8-apache
Mon Apr 27 00:51:21 UTC Creating application
Still creating application (10 seconds elapsed)
Mon Apr 27 00:51:36 UTC Generating the cluster image
Mon Apr 27 00:51:44 UTC Saving the image as wordpress.tar
Still saving the image as wordpress.tar (10 seconds elapsed)
Mon Apr 27 00:52:02 UTC Build finished in 3 minutes
Let's review what just happened. tele build did the following:
- Downloaded Kubernetes binaries and Gravity tooling from Gravitational distribution hub.
- Scanned the current directory and the subdirectories for Kubernetes resources and Helm charts.
- Downloaded external container images referenced in the resources discovered in the previous step.
- Packaged (or vendored) Docker images into the Cluster Image.
- Removed the duplicate container image layers, reducing the size of the Cluster Image.
- Saved the Cluster Image as
wordpress.tar.
Note: Slow Operation Warning
tele build needs to download hundreds of megabytes of binary dependencies which
can take a considerable amount of time, depending on your Internet connection speed.
The resulting wordpress.tar file is about 2.9GB and it is entirely
self-sufficient and dependency-free. It contains everything: the Kubernetes
binaries, the Docker engine, the Docker registry and the Wordpress application itself:
everything one needs to get Wordpress up and running on any fleet of Linux
servers (or into an AWS/GCE/Azure account).
Congratulations! You have created your first Kubernetes virtual appliance!
Installing the wordpress.tar Cluster Image results in creating a Kubernetes
cluster with the application pre-loaded. This file is the only artifact
one needs to create a Kubernetes cluster with Wordpress running inside.
Copy wordpress.tar to a clean Linux machine. Let's call it host. This node
will be used to bootstrap the cluster. Let's extract it and look inside:
$ tar -xf wordpress.tar
$ tree
├── app.yaml
├── gravity
├── gravity.db
├── install
├── packages
│ ├── blobs
│ │ ├── 0e1
│ │ ...
│ │ └── ff1
│ │ └── ff19bcf2dc62f037e0016d5d065150d195f714be3c97a301791365a4ec5a43f0
│ ├── tmp
│ └── unpacked
├── README
├── upgrade
└── uploadTo install a Cluster via CLI, you have to execute the ./gravity install command and
supply three flags:
| Flag | Description |
|---|---|
--token |
A secret token of your choosing which will be used to add additional nodes to this Cluster in the future. We'll use word "secret" here. |
--advertise-addr |
The IP address this host will be visible on by other nodes in this Cluster. We'll use 10.5.5.28. |
--cloud-provider |
Whether in a specific cloud environment or a no-cloud provider such as standalone VMs/bare-metal environment [generic aws gce] We'll use generic here. |
The command below will create a single-node Kubernetes cluster with Wordpress running inside:
# We are executing this on the node named 'host' with IP address of 10.5.5.28
$ sudo ./gravity install \
--advertise-addr=10.5.5.28 \
--token=secret \
--cloud-provider=generic
# Output:
Sun Apr 26 23:55:11 UTC Starting enterprise installer
To abort the installation and clean up the system,
press Ctrl+C two times in a row.
If you get disconnected from the terminal, you can reconnect to the installer
agent by issuing 'gravity resume' command.
If the installation fails, use 'gravity plan' to inspect the state and
'gravity resume' to continue the operation.
See https://gravitational.com/gravity/docs/cluster/#managing-operations for details.
Sun Apr 26 23:55:11 UTC Connecting to installer
Sun Apr 26 23:55:32 UTC Connected to installer
Sun Apr 26 23:55:32 UTC Successfully added "master" node on 10.150.15.236
...
Mon Apr 27 00:03:05 UTC Install application wordpress:0.0.1
Mon Apr 27 00:03:05 UTC Executing install hook for wordpress:0.0.1
Mon Apr 27 00:03:15 UTC Still executing install hook for wordpress:0.0.1 (10 seconds elapsed)
Mon Apr 27 00:03:16 UTC Executing "/connect-installer" locally
Mon Apr 27 00:03:17 UTC Connecting to installer
Mon Apr 27 00:03:17 UTC Connect to installer
Mon Apr 27 00:03:19 UTC Executing "/election" locally
Mon Apr 27 00:03:19 UTC Enable leader elections
Mon Apr 27 00:03:19 UTC Enable cluster leader elections
Mon Apr 27 00:03:20 UTC Executing operation finished in 6 minutes
Mon Apr 27 00:03:20 UTC The operation has finished successfully in 7m48s
Mon Apr 27 00:03:21 UTC
Cluster endpoints:
* Authentication gateway:
- 10.150.15.236:32009
* Cluster management URL:
- https://10.150.15.236:32009
Application endpoints:
* wordpress:0.0.1:
- wordpress:
- http://10.150.15.236:30080
Congratulations! You have created a fully functional Kubernetes cluster with Wordpress running inside. To check the health and status of the Cluster, execute this command on the target node:
$ sudo gravity status
Cluster name: wordpress
Cluster status: active
Cluster image: wordpress, version 0.0.1
Gravity version: 7.0.4 (client) / 7.0.4 (server)
Join token: c2d3757aec3e50d210e189dc16b1fb37
Periodic updates: Not Configured
Remote support: Not Configured
Last completed operation:
* 1-node install
ID: e5608f31-0d8e-4399-9987-00a96f0b41f8
Started: Sun Apr 26 23:55 UTC (1 hour ago)
Completed: Sun Apr 26 23:57 UTC (1 hour ago)
Cluster endpoints:
* Authentication gateway:
- 10.150.15.236:32009
* Cluster management URL:
- https://10.150.15.236:32009Navigate to http://<node ip>:30080 to access the application.
This is powered by the following service:
$ sudo kubectl get service wordpress
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
wordpress NodePort 100.100.204.73 <none> 80:30080/TCP 75m
Note that this is a single node deployment example. You have the option of joining or installing with a different flavor. The default flavor for this Cluster Manifest is small (1 node). Other flavors include medium (3 nodes) and large (5 nodes).
#Ex:
$ sudo ./gravity install \
--advertise-addr=10.5.5.28 \
--token=secret \
--cloud-provider=generic \
--flavor=medium
Flavor details are in the Wordpress Cluster Manifest . Flavors provide for specifying the number and configuration of nodes for a deployment.