Step 31: Using Redis to Store Sessions

Using Redis to Store Sessions

Depending on the website traffic and/or its infrastructure, you might want to use Redis to manage user sessions instead of PostgreSQL.

When we talked about branching the project’s code to move session from the filesystem to the database, we listed all the needed step to add a new service.

Here is how you can add Redis to your project in one patch:

patch_file

  1. --- a/.symfony.cloud.yaml
  2. +++ b/.symfony.cloud.yaml
  3. @@ -4,6 +4,7 @@ type: php:7.4
  5.  runtime:
  6.      extensions:
  7. +        - redis
  8.          - blackfire
  9.          - xsl
  10.          - pdo_pgsql
  11. @@ -26,6 +27,7 @@ disk: 512
  13.  relationships:
  14.      database: "db:postgresql"
  15. +    redis: "rediscache:redis"
  17.  web:
  18.      locations:
  19. --- a/.symfony/services.yaml
  20. +++ b/.symfony/services.yaml
  21. @@ -15,3 +15,6 @@ varnish:
  22.  files:
  23.      type: network-storage:1.0
  24.      disk: 256
  25. +
  26. +rediscache:
  27. +    type: redis:5.0
  28. --- a/config/packages/framework.yaml
  29. +++ b/config/packages/framework.yaml
  30. @@ -7,7 +7,7 @@ framework:
  31.      # Enables session support. Note that the session will ONLY be started if you read or write from it.
  32.      # Remove or comment this section to explicitly disable session support.
  33.      session:
  34. -        handler_id: '%env(DATABASE_URL)%'
  35. +        handler_id: '%env(REDIS_URL)%'
  36.          cookie_secure: auto
  37.          cookie_samesite: lax
  39. --- a/docker-compose.yaml
  40. +++ b/docker-compose.yaml
  41. @@ -17,3 +17,7 @@ services:
  42.          image: blackfire/blackfire
  43.          env_file: .env.local
  44.          ports: [8707]
  45. +
  46. +    redis:
  47. +        image: redis:5-alpine
  48. +        ports: [6379]

Isn’t it beautiful?

“Reboot” Docker to start the Redis service:

  1. $ docker-compose stop
  2. $ docker-compose up -d

Test locally by browsing the website; everything should still work as before.

Commit and deploy as usual:

  1. $ symfony deploy

Going Further

This work, including the code samples, is licensed under a Creative Commons BY-NC-SA 4.0 license.