Kubernetes (K8s)<\/strong> is a portable, extensible open-source container orchestration platform to manage containerized workloads and services, that makes easier declarative configuration deployment, scaling and automation. K8s<\/strong> lets you create, update and scale containers without worrying about server downtime.<\/p>\n Nginx acts as a proxy to PHP-FPM<\/a><\/u><\/span> when running a PHP application. It can be a cumbersome process if this setup is containerized<\/span> in a single container, but Kubernetes will help to manage both services in separate containers. K8s <\/b>allows you to keep your containers switchable and reusable, and you will not have to rebuild your container image every time there’s a new version of PHP or Nginx.<\/p>\n In this KB article, you will learn about<\/span> how to deploy a PHP 7 application on Kubernetes cluster with PHP-FPM and Nginx running in separate containers. Also, learn how to keep your application code and configuration files apart from the container image using DigitalOcean’s Block Storage<\/a><\/u><\/span> system. With<\/span> this perspective,<\/span> you can reuse the Nginx image for any application that requires web or proxy server by passing a configuration volume instead of rebuilding the image.<\/p>\n A basic understanding of Kubernetes objects.<\/p>\n<\/li>\n A Kubernetes cluster running on Ubuntu 16.04.<\/p>\n<\/li>\n A DigitalOcean account and an API access token with read and write permissions to create storage volume.<\/p>\n<\/li>\n Your application code hosted on a publicly accessible URL, like Github<\/a><\/u><\/span>.<\/p>\n<\/li>\n<\/ul>\n Here you will create the PHP-FPM and Nginx services. With the service you get an access to a set of pods<\/a> from inside the cluster. Without the requirement for IP addresses, these services can communicate directly within the cluster through their names. By using PHP-FPM service, you can access the PHP-FPM pods, while the Nginx service will allow access to the Nginx pods.<\/span><\/p>\n As Nginx pods will proxy the PHP-FPM pods, you have to tell the service the way<\/span> to find them. Instead of using IP addresses, Kubernetes’ automatic service discovery is beneficial to use human-readable names to route requests to the appropriate service.<\/p>\n To create the service, you have to create an object definition file. Every Kubernetes object definition is a YAML<\/b> file that includes at least the following items:<\/p>\n apiVersion<\/strong>: The Kubernetes API version that the definition belongs to.<\/p>\n kind<\/strong>: The Kubernetes object this file represents. For example, a pod<\/em><\/strong> or service<\/strong><\/em>.<\/p>\n metadata<\/strong>: This includes the object name with any labels that you may want to apply to it.<\/p>\n spec<\/strong>: This contains a particular setup relying upon the type of object you are creating, like the container image or the ports on which the container will be available from.<\/p>\n First, you have to create a directory to hold your Kubernetes object definitions.<\/p>\n SSH to your master node<\/strong> and make the definitions<\/strong> directory that will clutch your Kubernetes object definitions.<\/p>\n mkdir definitions<\/em><\/strong><\/p>\n Navigate to the newly created definitions<\/b> directory:<\/p>\n cd definitions<\/strong><\/em><\/p>\n Build your PHP-FPM service by creating a php_service.yaml<\/strong> file:<\/p>\n nano php_service.yaml<\/strong><\/em><\/p>\n Set kind<\/strong> as Service<\/strong> to define that this object is a service:<\/p>\n php_service.yaml<\/strong><\/p>\n …<\/em> Name the service php<\/b> as it will give access to PHP-FPM:<\/p>\n php_service.yaml<\/strong><\/p>\n …<\/em> You can group various objects logically with labels. In this knowledge base, you will use labels to group the objects within “tiers” like frontend or backend. The PHP pods will run back of this service so you can label it as tier: backend<\/strong>.<\/p>\n php_service.yaml<\/strong><\/p>\n …<\/em> A service figures out which pods to access by using selector<\/b> labels. A pod that coordinates these names will be serviced, independent of whether the pod was made before or after the service. You will include labels for your pods later in the tutorial.<\/p>\n Apply the tier: backend<\/b> label to assign the pod into the backend tier. Also, you have to add the app: php<\/b> label to define that this pod runs PHP. Add these two labels after the metadata<\/b> section.<\/p>\n php_service.yaml<\/strong><\/p>\n …<\/em> Next, define the port used to access this service. You will use port 9000<\/strong> in this tutorial. Add this port to the php_service.yaml<\/strong> file under spec<\/strong>:<\/p>\n php_service.yaml<\/strong><\/p>\n …<\/em> Done! Your created php_service.yaml<\/strong> file will look like this:<\/p>\n php_service.yaml<\/strong><\/p>\n apiVersion: v1<\/em> Hit CTRL + o<\/strong> to save the file, and then CTRL + x<\/strong> to exit nano.<\/p>\n Now that you have created the object definition for your service, to run this service you will use the kubectl apply<\/strong> command plus the -f<\/strong> argument and mention your php_service.yaml<\/strong> file.<\/p>\n Create your service:<\/p>\n kubectl apply -f php_service.yaml<\/strong><\/em><\/p>\n Following output authenticates service creation:<\/p>\n Output<\/strong> Check that your service is running:<\/p>\n kubectl get svc<\/strong><\/em><\/p>\n You will notice your PHP-FPM service running:<\/p>\n Output<\/strong>Prerequisites<\/h2>\n
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STEP 1 – Create the PHP-FPM and Nginx Services<\/h2>\n
\napiVersion: v1<\/em>
\nkind: Service<\/em><\/p>\n
\nmetadata:<\/em>
\n name: php<\/em><\/p>\n
\nlabels:<\/em>
\n tier: backend<\/em><\/p>\n
\nspec:<\/em>
\n selector:<\/em>
\n app: php<\/em>
\n tier: backend<\/em><\/p>\n
\nports:<\/em>
\n – protocol: TCP<\/em>
\n port: 9000<\/em><\/p>\n
\nkind: Service<\/em>
\nmetadata:<\/em>
\n name: php<\/em>
\n labels:<\/em>
\n tier: backend<\/em>
\nspec:<\/em>
\n selector:<\/em>
\n app: php<\/em>
\n tier: backend<\/em>
\n ports:<\/em>
\n – protocol: TCP<\/em>
\n port: 9000<\/em><\/p>\n
\nservice\/php created<\/em><\/p>\n
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