Propagate the patterns used in cmd/check-ip to the other command-line
tools touched by this PR:
- flag.FlagSet + Config struct instead of package-level flag.String
pointers (geoip-update, ipcohort-contains, git-shallow-sync).
- -V/--version/version and help/-help/--help handled before Parse,
matching the project's CLI conventions.
- Stderr "Loading X... Nms (counts)" progress lines on the stages that
actually take time: blocklist cohort parse (ipcohort-contains),
per-edition fetch (geoip-update), and repo sync (git-shallow-sync).
Stdout stays machine-parseable.
Adds geoip.TarGzName(edition) as the single source of truth for the
cache filename. The _LATEST suffix signals that the file is whatever
MaxMind served most recently (versus the dated Content-Disposition
name) and keeps httpcache's ETag sidecar tied to a stable path across
releases.
Cacher.Header is a stdlib http.Header that's merged into every request.
Authorization is stripped on redirect unconditionally (presigned S3/R2
targets, etc). Callers build the header with the usual http.Header
literal; BasicAuth/Bearer still produce the Authorization value.
The old ParseConf opened the file itself, which the name did not
convey. Now it parses the config text directly, matching
encoding/json.Unmarshal-style conventions: callers read the file (or
source the string however they like) and pass it in. Also introduce
errors.ErrMissingCredentials for the credential-missing case so callers
can branch on it.
- httpcache.Cacher loses Transform (always atomic copy to Path); adds
BasicAuth and Bearer helpers for Authorization header values.
- geoip.Open now reads <dir>/GeoLite2-City.tar.gz and GeoLite2-ASN.tar.gz
directly: extracts the .mmdb entry in memory and opens via
geoip2.FromBytes. No .mmdb files written to disk.
- geoip.Downloader/New/NewCacher/Fetch/ExtractMMDB removed — geoip is
purely read/lookup; fetching is each caller's concern.
- cmd/check-ip/main.go is a single main() again: blocklists via
gitshallow+dataset, geoip via two httpcache.Cachers (if GeoIP.conf
present) + geoip.Open. No geo refresh loop, no dataset.Group for geo.
- cmd/geoip-update and the integration test construct httpcache.Cachers
directly against geoip.DownloadBase + edition IDs, writing .tar.gz.
geoip.ParseConf() extracted from geoip-update into the geoip package so
both cmds can read GeoIP.conf without duplication.
check-ip gains -geoip-conf flag: reads AccountID+LicenseKey, resolves
mmdb paths into data-dir, builds httpcache.Cachers with geoip.NewCacher.
Background runLoop now refreshes both blocklists and GeoIP DBs on each
tick, hot-swapping geoip2.Reader via atomic.Pointer.Swap + old.Close().
