ledger-tool: add warn log if capitalization changes during create-snapshot

[CriesofCarrots]

Problem

As brought up here, solana-ledger-tool create-snapshot operations that change the capitalization are intended for testing purposes and should be used with caution. The script silently calls Bank::set_capitalization() regardless of whether such operations are included. Node operators use this script on restarts on live clusters, like mainnet-beta, so it's worth taking extra care to ensure capitalization changes are intended.

Summary of Changes

Check capitalization before and after Bank::set_capitalization() and emit a warning if the value changes.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (897adb2) 81.6% compared to head (bd1216f) 81.6%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #35155   +/-   ##
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  Coverage    81.6%    81.6%           
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  Files         833      833           
  Lines      224827   224827           
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+ Hits       183523   183562   +39     
+ Misses      41304    41265   -39     

[steviez]

Like the idea, I'm afraid the warning will get buried though. Maybe do the actual outputting at the end ?

Given the severity, I thought about suggesting adding a flag like --enable-capitalization-difference. However, I could see that something that just gets included in instructions / copy-pasted blindly. What do you think ?

[CriesofCarrots]

Maybe do the actual outputting at the end ?

Maybe both? I agree it's easy to lose the WARNs in the sea of INFOs (that said, it would be nice if INFO wasn't so verbose).

Given the severity, I thought about suggesting adding a flag like --enable-capitalization-difference.

I like it. Blind c+p is always an issue, but at least we have a "should have known better" to point to, instead of a silent footgun. I'll add to this PR.

[steviez]

LGTM