Fix bootstrap script

[davidsiaw]

A small change to Rails 5.2 meant that running rake tasks now checks for the presence of SECRET_KEY_BASE all the time. This probably wasn't the case when the script was first written.

This PR fixes the bootstrap script so it runs properly. Before, the script just dies with a cryptic message

/app/lib/tasks/bootstrap.rake:96:in `block (2 levels) in <top (required)>': Provisioning failed. (RuntimeError)

Further investigation (reading the logs sent to cloudwatch logs) revealed it was lacking the secret key base. (Also pretty cryptic)

ArgumentError: Missing `secret_key_base` for 'production' environment, set this string with `rails credentials:edit`

The way our bootstrap script works may be obsolete. In the future we will need to generate the credentials.yml.enc file and store it on S3 to be downloaded by containers before running rails and set the RAILS_MASTER_KEY env var on all instances.

[degicat]

@Resonious please review this

[Resonious]

@davidsiaw Change makes sense but I think there's a small error. Let me know if I'm just seeing things wrong 😆

[Resonious]

I may be crazy, but it looks to me like this secret_key_base local variable is defined in the task bcn:bootstrap, and right here it is being used by the task bcn:bootstrap:remote. Those are different Ruby scopes so I suspect this line here will error out.

We can probably just keep the inline call to SecureRandom.hex(64) here, right?

[davidsiaw]

Oh yeah. That is odd. I wonder why this worked... It may have been because the variable was re-evaluated. You're right. It can just be the same key base here too.