# Hello World - PHP

A simple web app written in PHP that you can use for testing. It reads in an env
variable `TARGET` and prints `Hello ${TARGET}!`. If `TARGET` is not specified,
it will use `World` as the `TARGET`.

Do the following steps to create the sample code and then deploy the app to your
cluster. You can also download a working copy of the sample, by running the
following commands:

```bash
git clone https://github.com/knative/docs.git knative-docs
cd knative-docs/code-samples/serving/hello-world/helloworld-php
```

## Before you begin

- A Kubernetes cluster with Knative installed and DNS configured. See
  [Install Knative Serving](https://knative.dev/docs/install/serving/install-serving-with-yaml).
- [Docker](https://www.docker.com) installed and running on your local machine,
  and a Docker Hub account configured (we'll use it for a container registry).

## Recreating the sample code

1. Create a new directory and cd into it:

   ```bash
   mkdir app
   cd app
   ```

1. Create a file named `index.php` and copy the following code block into it:

   ```php
   <?php
   $target = getenv('TARGET', true) ?: 'World';
   echo sprintf("Hello %s!\n", $target);
   ?>
   ```

1. Create a file named `Dockerfile` and copy the following code block into it. See
   [official PHP docker image](https://hub.docker.com/_/php/) for more details.

   ```docker
   # Use the official PHP 7.3 image.
   # https://hub.docker.com/_/php
   FROM php:7.3-apache

   # Copy local code to the container image.
   COPY index.php /var/www/html/

   # Use the PORT environment variable in Apache configuration files.
   RUN sed -i 's/80/${PORT}/g' /etc/apache2/sites-available/000-default.conf /etc/apache2/ports.conf

   # Configure PHP for development.
   # Switch to the production php.ini for production operations.
   # RUN mv "$PHP_INI_DIR/php.ini-production" "$PHP_INI_DIR/php.ini"
   # https://hub.docker.com/_/php#configuration
   RUN mv "$PHP_INI_DIR/php.ini-development" "$PHP_INI_DIR/php.ini"
   ```

1. Create a `.dockerignore` file to ensure that any files related to a local
   build do not affect the container that you build for deployment.

   ```ignore
   README.md
   ```

1. Create a new file, `service.yaml` and copy the following service definition
   into the file. Make sure to replace `{username}` with your Docker Hub
   username.

   ```yaml
   apiVersion: serving.knative.dev/v1
   kind: Service
   metadata:
     name: helloworld-php
     namespace: default
   spec:
     template:
       spec:
         containers:
           - image: docker.io/{username}/helloworld-php
             env:
               - name: TARGET
                 value: "PHP Sample v1"
   ```

## Building and deploying the sample

Once you have recreated the sample code files (or used the files in the sample
folder) you're ready to build and deploy the sample app.


=== "yaml"

    1. Use Docker to build the sample code into a container. To build and push with
       Docker Hub, run these commands replacing `{username}` with your Docker Hub
       username:

       ```bash
       # Build the container on your local machine
       docker build -t {username}/helloworld-php .

       # Push the container to docker registry
       docker push {username}/helloworld-php
       ```

    1. After the build has completed and the container is pushed to docker hub, you
       can deploy the app into your cluster. Ensure that the container image value
       in `service.yaml` matches the container you built in the previous step. Apply
       the configuration using `kubectl`:

       ```bash
       kubectl apply --filename service.yaml
       ```


=== "kn"

       With `kn` you can deploy the service with

       ```bash
       kn service create helloworld-php --image=docker.io/{username}/helloworld-php --env TARGET="Ruby Sample v1"
       ```

       This will wait until your service is deployed and ready, and ultimately it will print the URL through which you can access the service.

       The output will look like:

       ```
       Creating service 'helloworld-php' in namespace 'default':

        0.035s The Configuration is still working to reflect the latest desired specification.
        0.139s The Route is still working to reflect the latest desired specification.
        0.250s Configuration "helloworld-php" is waiting for a Revision to become ready.
        8.040s ...
        8.136s Ingress has not yet been reconciled.
        8.277s unsuccessfully observed a new generation
        8.398s Ready to serve.

      Service 'helloworld-php' created to latest revision 'helloworld-php-akhft-1' is available at URL:
      http://helloworld-php.default.1.2.3.4.xip.io
      ```





1. Now that your service is created, Knative will perform the following steps:

   - Create a new immutable revision for this version of the app.
   - Network programming to create a route, ingress, service, and a load balancer
     for your app.
   - Automatically scale your pods up and down (including to zero active pods).

1. To find the URL for your service, use


=== "kubectl"

       ```
       kubectl get ksvc helloworld-php  --output=custom-columns=NAME:.metadata.name,URL:.status.url
       NAME                URL
       helloworld-php      http://helloworld-php.default.1.2.3.4.xip.io
       ```


=== "kn"

       ```bash
       kn service describe helloworld-php -o url
       ```

       Example:

       ```bash
       http://helloworld-php.default.1.2.3.4.xip.io
       ```




1. Now you can make a request to your app and see the result. Replace
   the following URL with the URL returned in the previous command.

   ```bash
   curl http://helloworld-php.default.1.2.3.4.sslip.io
   Hello PHP Sample v1!
   ```

## Removing the sample app deployment

To remove the sample app from your cluster, delete the service record.


=== "kubectl"
    ```bash
    kubectl delete --filename service.yaml
    ```

=== "kn"

    ```bash
    kn service delete helloworld-php
    ```
