App Engine (PHP) connection to Cloud SQL failed - php

Question

I used the environment of the "hello world" app engine example by google to create my own php app. Then i configured the existing app.yaml file to this:
runtime: php55
api_version: 1
handlers:
- url: /
script: index.php
env_variables:
MYSQL_DSN: mysql:dbname=sampledb;unix_socket=/cloudsql/sampleproject:europe-west3:sampleinstance
MYSQL_USER: root
MYSQL_PASSWORD: admin
My index.php is a typical login page. I want to load user data from my cloud sql to check, whether the user is allowed to enter the next page or not. The next page is a dashboard which includes company data. I also want to load this data from my cloud sql databse.
That's my php code to read the data (i copied it from the google bookshelf tutorial, because i am completly new into these things..)
<?php
$dsn = getenv('MYSQL_DSN');
$user = getenv('MYSQL_USER');
$password = getenv('MYSQL_PASSWORD');
if (!isset($dsn; $user) || false=== $password) {
throw new Exception('Set MYSQL_DSN');
}
$db = new PDO($dsn, $user, $password);
$statement = $db->prepare("SELECT clicks from display_inbox");
$statement->execute();
$all = $statement->fetchAll();
foreach ($all as $data) {
echo $data["clicks"], "<br>";
}
?>
It's not a specific query,i just want to check the connection.
After deploying my app i get the following result:
HTTP-500 error: sampleproject.appspot.com is currently unable to handle this request.
I simply don't get if it's my app.yaml or my php code. Would be very helpful if anybody has an example code for a app.yaml file and a typical query to read the cloud sql data.

Answer 1

You have some syntax errors in your app.yaml and index.php files
Try this:
app.yaml:
runtime: php55
api_version: 1
threadsafe: true
handlers:
- url: /.*
script: index.php
# [START env]
env_variables:
MYSQL_DSN: mysql:unix_socket=/cloudsql/sampleproject:europe-west3:sampleinstance;dbname=sampledb
MYSQL_USER: root
MYSQL_PASSWORD: admin
# [END env]
index.php:
<?php
$dsn = getenv('MYSQL_DSN');
$user = getenv('MYSQL_USER');
$password = getenv('MYSQL_PASSWORD');
if (!isset($dsn, $user) || false === $password) {
throw new Exception('Set MYSQL_DSN');
}
$db = new PDO($dsn, $user, $password);
$statement = $db->prepare("SELECT clicks from display_inbox");
$statement->execute();
$all = $statement->fetchAll();
foreach ($all as $data) {
echo $data["clicks"]."<br>";
}
?>