Use 'GeoLite2-City.mmdb' / 'GeoLite2-ASN.mmdb' directly instead of
composing from the edition constants. Reads plainly — the actual
filename is right there.
Filenames are deterministic (<dir>/GeoLite2-City.mmdb,
<dir>/GeoLite2-ASN.mmdb) — callers no longer pass both paths. cmd/check-ip
drops its cityPath/asnPath locals and just hands the maxmind dir to
geoip.Open and the fetcher builder.
geoip.Open now just opens files; download/refresh/polling logic lives at
the cmd layer using dataset.Group with a combined httpcache.Cacher
fetcher (or PollFiles when no GeoIP.conf is available). Removes
geoip.OpenDatabases — the library is no longer concerned with refresh.
- drop Checker struct, loadCohort helper, and contains() nil-wrapper
- inline check logic into server as a closure
- geoip.Databases: no nil-receiver guards, no nil-field branches, no
"disabled" mode. City + ASN are both required; caller hands explicit
paths and OpenDatabases returns a fully-initialized value or an err
- main.go is now straight-line wiring with no helper functions
geoip.Databases now exposes a structured Lookup(ip) Info. Rendering
moved up to the cmd — the library no longer writes to io.Writer.
check-ip adds a Result struct and --format flag (pretty/json). Serve
mode dispatches on ?format=json or Accept: application/json. Pretty
is the default for both one-shot and HTTP.
Databases is now just two *geoip2.Reader fields with Open/Close/PrintInfo.
OpenDatabases still auto-discovers conf and downloads stale .mmdb files
via httpcache before opening, but it no longer runs background goroutines
or holds atomic pointers. Long-running callers that want refresh can wire
httpcache.Cacher to atomic.Pointer themselves.
check-ip drops geo.Init/geo.Run — OpenDatabases does the fetch+open work
itself, and a one-shot CLI doesn't need background refresh.
