docs(ipcohort): update README for current API + sync/dataset

Fixes API drift (Init/Sync no longer take a force arg) and adds the
recommended sync/dataset pattern alongside the manual atomic.Pointer
fallbacks for both gitshallow and httpcache.
This commit is contained in:
AJ ONeal 2026-04-30 17:17:30 -06:00
parent f459f98139
commit d37bd1d08c
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@ -23,11 +23,58 @@ if cohort.Contains("92.255.85.72") {
fmt.Println("allowed")
```
## Update the list periodically: git (shallow)
`Cohort.Contains(string)` parses the address each call. If you already have
a `netip.Addr` (e.g. from `netip.ParseAddr` on a request peer), use
`Cohort.ContainsAddr(netip.Addr)` to skip the parse.
## Recommended: hot-swap with `sync/dataset`
`sync/dataset` wraps the `atomic.Pointer` + refresh-loop boilerplate so live
requests see the new list without locks or restarts. Pair it with either
`gitshallow` (best when you want incremental updates and don't mind a `git`
binary in the runtime image) or `httpcache` (best for minimal images that
just need a single file over HTTPS).
```go
import (
"context"
"time"
"github.com/therootcompany/golib/net/gitshallow"
"github.com/therootcompany/golib/net/ipcohort"
"github.com/therootcompany/golib/sync/dataset"
)
repo := gitshallow.New(
"https://github.com/bitwire-it/ipblocklist.git",
"/srv/data/ipblocklist", 1, "",
)
set := dataset.NewSet(repo)
view := dataset.Add(set, func(ctx context.Context) (*ipcohort.Cohort, error) {
return ipcohort.LoadFile(repo.FilePath("tables/inbound/single_ips.txt"))
})
if err := set.Load(ctx); err != nil {
log.Fatalf("initial load: %v", err)
}
go set.Tick(ctx, 47*time.Minute, func(err error) { log.Printf("refresh: %v", err) })
// in a request handler:
if view.Value().Contains(peerIP) {
http.Error(w, "blocked", http.StatusForbidden)
return
}
```
## Manual hot-swap: git (shallow)
Without `sync/dataset` if you want to keep the dependency surface small:
```go
import (
"sync/atomic"
"time"
"github.com/therootcompany/golib/net/gitshallow"
"github.com/therootcompany/golib/net/ipcohort"
@ -38,10 +85,10 @@ var cohort atomic.Pointer[ipcohort.Cohort]
repo := gitshallow.New("https://github.com/bitwire-it/ipblocklist.git", "/srv/data/ipblocklist", 1, "")
// Init: clone if missing, pull, load.
if _, err := repo.Init(false); err != nil {
if _, err := repo.Init(); err != nil {
log.Fatalf("init: %v", err)
}
c, err := ipcohort.LoadFile("/srv/data/ipblocklist/tables/inbound/single_ips.txt")
c, err := ipcohort.LoadFile(repo.FilePath("tables/inbound/single_ips.txt"))
if err != nil {
log.Fatalf("load: %v", err)
}
@ -49,10 +96,8 @@ cohort.Store(c)
// Background: pull and reload when HEAD changes.
go func() {
ticker := time.NewTicker(47 * time.Minute)
defer ticker.Stop()
for range ticker.C {
updated, err := repo.Sync(false)
for range time.Tick(47 * time.Minute) {
updated, err := repo.Sync()
if err != nil {
log.Printf("sync: %v", err)
continue
@ -60,22 +105,26 @@ go func() {
if !updated {
continue
}
c, err := ipcohort.LoadFile("/srv/data/ipblocklist/tables/inbound/single_ips.txt")
c, err := ipcohort.LoadFile(repo.FilePath("tables/inbound/single_ips.txt"))
if err != nil {
log.Printf("reload: %v", err)
continue
}
cohort.Store(c)
log.Printf("reloaded %d entries", cohort.Load().Size())
log.Printf("reloaded %d entries", c.Size())
}
}()
```
## Update the list periodically: HTTP (cache)
## Manual hot-swap: HTTP (cache)
Same pattern with `httpcache` for minimal runtime images that don't have
`git`:
```go
import (
"sync/atomic"
"time"
"github.com/therootcompany/golib/net/httpcache"
"github.com/therootcompany/golib/net/ipcohort"
@ -99,9 +148,7 @@ cohort.Store(c)
// Background: conditional GET, reload only when content changes.
go func() {
ticker := time.NewTicker(47 * time.Minute)
defer ticker.Stop()
for range ticker.C {
for range time.Tick(47 * time.Minute) {
updated, err := cacher.Fetch()
if err != nil {
log.Printf("fetch: %v", err)
@ -116,7 +163,7 @@ go func() {
continue
}
cohort.Store(c)
log.Printf("reloaded %d entries", cohort.Load().Size())
log.Printf("reloaded %d entries", c.Size())
}
}()
```