Graffiti hex support

[d00medman]

What type of PR is this?
Feature

What does this PR do? Why is it needed?
When a user provides a string prefixed with "hex:" followed by a hexidecimal string, this change will cause that piece of graffiti to be converted to ascii characters. It was deemed a reasonable feature for the system to have

Which issues(s) does this PR fix?

Fixes #8168

Other notes for review
Performs the conversion to ascii at startup; original value of yaml file captured by the hash field of the graffiti struct. Opted to make conversion errors non-blocking, when this happens the graffiti will be "hex:whatever"

[rkapka]

Opted to make conversion errors non-blocking, when this happens the graffiti will be "hex:whatever"

This doesn't seem to be covered by any test case. Also I am not that big of a fan of whatever. I would prefer leaving the graffiti empty or providing something more meaningful like [parse error]. I don't have a strong opinion on this one, though.

[d00medman]

Opted to make conversion errors non-blocking, when this happens the graffiti will be "hex:whatever"

This doesn't seem to be covered by any test case. Also I am not that big of a fan of whatever. I would prefer leaving the graffiti empty or providing something more meaningful like [parse error]. I don't have a strong opinion on this one, though.

So the "whatever" isn't actually what you'll get as an output, I just used it as a stand in. For example, if you put "hex:test 123", the graffiti used by the validator will be "hex:test 123", apologies for the lack of clarity here

[rkapka]

Thanks for addressing my comments @d00medman. You need to run bazel run //:gazelle -- fix to make the build happy. This will update package dependencies.

[rauljordan]

PTAL @rkapka

[0xKiwi]

E2E is currently failing with the following error:

    assertions.go:85: endtoend_test.go:221 Evaluation failed for epoch 1: could not get graffiti from the list: could not get graffiti from the list

[prestonvanloon]

Please address e2e failure

[rndstr]

just some drive-by nits, feel free to ignore

[prestonvanloon]

Looks like some build failures:

validator/graffiti/parse_graffiti.go:64:42: undefined: hexGraffitiPrefixKey

[d00medman]

It is unclear to me why the e2e test is failing; eyeball test alone is not doing the trick. I have thus far been unsuccessful in running this suite locally, any help in doing so would be very helpful.

[prestonvanloon]

Its failing to write the correct graffiti. You also have unit test failures. I imagine that if you fix the issues causing failures in the unit test, then you'll also fix the issue in the e2e tests.

[prestonvanloon]

E2E is failing for this error

assertions.go:85: endtoend_test.go:221 Evaluation failed for epoch 1: could not get graffiti from the list: could not get graffiti from the list

[prestonvanloon]

The e2e test is supposed to use a random graffiti, and i see that this block had no graffiti.

time="2021-06-09 16:50:41" level=info msg="Submitted new block" blockRoot=0x5b303b82d7ec graffiti="\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00" numAttestations=4 numDeposits=0 prefix=validator pubKey=0x87bbd5574c17 slot=1

[prestonvanloon]

Without changing the unit tests, if you can make all of TestParseGraffitiFile_* pass, then I believe e2e should pass as well. There are multiple test failures there when parsing a graffiti file.

[codecov]

Codecov Report

Merging #8894 (d10fe42) into develop (0d8dd8d) will decrease coverage by 0.01%.
The diff coverage is 86.36%.

@@             Coverage Diff             @@
##           develop    #8894      +/-   ##
===========================================
- Coverage    60.78%   60.77%   -0.02%     
===========================================
  Files          531      531              
  Lines        37862    37883      +21     
===========================================
+ Hits         23015    23022       +7     
- Misses       11567    11579      +12     
- Partials      3280     3282       +2     

[prestonvanloon]

Amazing work! Thanks so much