Netgroup inbound peer eviction and secret generation - Closes #3976

[mitsuaki-u]

What was the problem?

Eviction of inbound peers based on netgroup value was not implemented.

Node required a random 32-bit entropy secret on startup.

How did I solve it?

Peers are now evicted based on 4 categories including netgroup value as per new protocol.
Secret generated on node startup.

How to manually test it?

Start node. Set netgroupProtectionRatio to a high value for P2PConfig. Check which peers are evicted.

Review checklist

• The PR resolves Use netgrouping for inbound evictions #3976 Generate 32-bit entropy random secret on node startup #3970
• All new code is covered with unit tests
• Relevant integration / functional tests are added
• Commit messages follow the commit guidelines
• Documentation has been added/updated

Addressed.

[shuse2]

Shouldn't this issue also save the secret to the database?

[mitsuaki-u]

Shouldn't this issue also save the secret to the database?

After discussion with @jondubois we decided to delay persistence to db until a later release. The effect was minimal enough that it can be seen as an optimization rather than necessity.

[shuse2]

LGTM, Please open an issue for saving the secret to the database =)

[diego-G]

I've left few comments. Besides, I'd like to relapse if the features we are adding in this PR is actually covered with any of the existing integration tests.

[mitsuaki-u]

I've left few comments. Besides, I'd like to relapse if the features we are adding in this PR is actually covered with any of the existing integration tests.

There is the limiting factor of not being able to fake the first two IP address groups in integration tests. However the getNetgroup function itself is already covered by unit tests. The new code in this PR is the use of netgroup in protecting some inbound peers from eviction. The functionality is identical with protecting peers for connectTime, which is already covered by integration test.

Addressed.

Addressed