PHP sessions and email configuration

Configure the session storage

By default, an FS Bucket is created for each PHP application, so that session data is available on each instance. This FS Bucket is also used to store TMP files by default. You can change this behavior by setting the TMPDIR environment variable. You can set it to /tmp for example.

Speed up or disable the session FS Bucket

You can set the following environment variables:

• CC_PHP_ASYNC_APP_BUCKET=async to mount the session FS Bucket with the async option. It speeds up the FS Bucket usage, but it can corrupt files in case of a network outage.
• CC_PHP_DISABLE_APP_BUCKET=(true|yes|disable) to entirely prevent the session FS Bucket from being mounted. Use this if you don’t use the default PHP session library. It will speed up your application but users might lose their session across instances and deployments.

Use Materia KV or Redis to store PHP Sessions

Clever Cloud allows you to store PHP sessions easily in a Materia KV or Redis add-on to improve performance/reliability.

To enable this feature, you need to:

• Set ENABLE_REDIS=true as environment variable in the PHP application
• Set SESSION_TYPE=redis as environment variable in the PHP application
• Create and link a Materia KV or Redis add-on to the PHP application

Sending emails

The PHP language has the mail function to directly send emails. While no SMTP server is provided (needed to send the emails), you can configure one through environment variables.

Mailpace add-on can send emails through PHP mail() function. You have to turn TLS on with port 465 (environment variable CC_MTA_SERVER_USE_TLS=true) to make Mailpace working.

Mailgun or Mailjet are also recommended if your project supports it. These services already have everything you need to send emails from your code.

Configure the SMTP server

Services like Mailgun or Mailjet provide SMTP servers. If your application has no other way but to use the mail function of PHP to send emails, you have to configure a SMTP server. This can be done through environment variables: