[Enhancement] Add a flag to setup default admin:admin in demo script

[RyanL1997]

Description

Add a flag to setup default admin:admin in demo script

• Category (Enhancement, New feature, Bug fix, Test fix, Refactoring, Maintenance, Documentation)
  Enhancement

Issues Resolved

• Relate Demo configuration script requires admin password #3329
• Relate [Security] Demo configuration script requires admin password  opensearch-build#4094

Is this a backport? If so, please add backport PR # and/or commits #

Testing

CI

Check List

• New functionality includes testing
• New functionality has been documented
• Commits are signed per the DCO using --signoff

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[peternied]

This change lowers the security posture by allow setting the password to a preconfigured value, I feel strongly we should not merge a change of this nature.

[RyanL1997]

@peternied Thanks for the feedback! Lets move our conversation here. This PR is demo approach of one of the potential solutions that me, @DarshitChanpura and @peterzhuamazon discussed. Feel free to drop some thoughts on that open issue in build repo.

[codecov]

Codecov Report

Merging #3441 (6b0f5a9) into main (1ffa23c) will increase coverage by 0.01%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##               main    #3441      +/-   ##
============================================
+ Coverage     64.50%   64.52%   +0.01%     
  Complexity     3545     3545              
============================================
  Files           269      269              
  Lines         20363    20363              
  Branches       3375     3375              
============================================
+ Hits          13135    13139       +4     
+ Misses         5533     5529       -4     
  Partials       1695     1695              

see 1 file with indirect coverage changes

[DarshitChanpura]

@peterzhuamazon shared his perspective from build side and I share the sentiment. Here is an approach that allows us to gradually bring this change in :

1. We allow passing an additional inline argument with initialAdminPassword
2. If the argument is not present, we then prompt user during installation script to provide an admin password.
3. (For now) If they choose to not provide password we default it to admin with a warning message in next release this option will be removed, and in next release we remove it. (For 2.11 it might be too close to make this call especially with CI builds and RC generation)

[peternied]

I believe there are other options that are being looked into to handle the rollout process around changing the default password. Lets reopen this change if the rollout process indicates its the path forward.