NewPseudoRand returns an instance of math/rand.Rand seeded from the environment variable COCKROACH_RANDOM_SEED.

NewPseudoSeed generates a seed from crypto/rand.

RandBytes returns a byte slice of the given length with random data.

RandIntInRange returns a value in [min, max).

ReadTestdataBytes reads random bytes, but then nudges them into printable ASCII, *reducing their randomness* to make them a little friendlier for humans using them as testdata.

SeedForTests seeds the random number generator and prints the seed value used.