Upgrade Ruby version while deploying to EB

Question

I have a production rails application on Ruby 2.2.5 but I updated my app to ruby 2.5.3 and rails from 4.2 to 5.2 . When I try to deploy this to ElasticBeanstalk I get the following errors everytime:

Warning: the running version of Bundler is older than the version that created the lockfile. 
We suggest you upgrade to the latest version of Bundler by running `gem install bundler`.
Your Ruby version is 2.2.5, but your Gemfile specified 2.5.3. 
Hook /opt/elasticbeanstalk/hooks/appdeploy/pre/10_bundle_install.sh failed. For more detail, check /var/log/eb-activity.log using console or EB CLI.

To fix this I ssh'd into the instance and installed rvm before updating the ruby version using

rvm --default use 2.5.3

After this I updated my bundler as suggested in the error message but it seems like the ruby version gets reset to 2.2.5 everytime I close my connection and ssh in again because doing

ruby -v gives 2.2.5

How can I update the ruby version on my instance?

Answer 1

Elastic Beanstalk sets the Ruby version in the Platform (you can think of this as the base AMI). To upgrade this you'll need to update your platform version .

Depending on the web server you use, it sounds like you'll need one of:

• 64bit Amazon Linux 2018.03 v2.8.7 running Ruby 2.5 (Puma)
• 64bit Amazon Linux 2018.03 v2.8.7 running Ruby 2.5 (Passenger Standalone)