Metabase stores connection information for the various databases you add in the Metabase application database. To prevent bad actors from being able to access these details if they were to gain access to
the application DB, Metabase can automatically encrypt them when they are saved, and decrypt them on-the-fly whenever they are needed. The only thing you need to do is set the environment variable
Your secret key must be at least 16 characters (longer is even better!), and we recommend using a secure random key generator to generate it.
openssl is a good choice:
openssl rand -base64 32
This gives you a cryptographically-secure, randomly-generated 32-character key that will look something like
IYqrSi5QDthvFWe4/WdAxhnra5DZC3RKx3ZSrOJDKsM=. Set it as an environment variable and
start Metabase as usual:
MB_ENCRYPTION_SECRET_KEY='IYqrSi5QDthvFWe4/WdAxhnra5DZC3RKx3ZSrOJDKsM=' java -jar metabase.jar
Metabase will securely encrypt and store the connection details for any new Databases you add. (Connection details for existing databases will be encrypted as well if you save them in the admin panel). Existing databases with unencrypted details will continue to work normally.
Take care not to lose this key because you can’t decrypt connection details without it. If you lose (or change) it, you’ll have to reset all of the connection details that have been encrypted with it in the Admin Panel.