Extracts the Redis pool and the cached_mysql / mysqlredis datastore
wrappers out of `runServeCmd` and into a new `cmd/fleet/redis.go`. Same
pattern as the prior extractions on this issue (#44929, #45343, #45583,
#46166, #46421, #46517, #46742). Continues the path toward `serve.go`
>60% coverage per the discussion on #33370.
Three functions come out of the inline block:
- `initRedis` — builds the Redis pool, wraps the datastore with
`cached_mysql.New`, and applies `mysqlredis.New` with the
license-enforced host limit and host-cache options. Returns the pool,
the fully wrapped `fleet.Datastore`, and the outermost
`*mysqlredis.Datastore` (a few callers need the concrete type).
- `buildRedisPoolConfig` — translates `config.RedisConfig` into the
`redis.PoolConfig`, including the `redis://` scheme strip.
- `validateRedisConfig` — encodes the host-cache invariant:
`HostCacheEnabled` requires `HostCacheTTL > 0`. Returns an error so the
caller (or in this case `initRedis` via `initFatal`) can refuse boot
without that decision being buried inside a pure builder.
Behavior is preserved — `runServeCmd` calls these in the same order with
the same arguments, the host-cache validation still aborts startup when
violated, and the full `cmd/fleet` suite passes against MySQL + Redis.
`initRedis` returns early after `initFatal` so it's safe when the
caller's `initFatal` doesn't terminate (the case in tests). Following
the precedent established on #46742, the caller also has a loud
`initFatal` + `return` guard against a nil pool (covers the same nilaway
flow we hit on the datastore slice).
On test scope: `TestValidateRedisConfig` covers all four combinations of
`HostCacheEnabled` and `HostCacheTTL` — that's the real
boot/refuse-to-boot decision. `TestBuildRedisPoolConfigStripsScheme`
pins the `redis://` scheme-strip contract for Render-style URIs. I
didn't add a `buildRedisPoolConfig` field-mapping matrix or an
`initRedis` happy-path unit test: the former would just re-state the
struct literal, and the latter needs a real Redis pool (the smoke boot
exercises it end-to-end instead).
This completes the four named init-block extractions on this issue. If
further coverage gains are needed beyond what these have already moved,
the next conversation is whether to test `runServeCmd` directly via the
injected `initFatal`.
**Related issue:** Refs #33370
# Checklist for submitter
- [x] Added/updated automated tests
- Changes file: not applicable — internal refactor with no user-visible
behavior change
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Refactor**
* Consolidated Redis initialization and datastore wrapping into a
dedicated helper; startup now validates the Redis pool and handles
initialization failures explicitly.
* **Tests**
* Added unit tests for Redis address handling and host-cache TTL
validation to ensure config behavior is enforced.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Rajendra kadam
8bda07655c