feat: implement a client for Thoth, the IP reputation database for Anubis (#637)

* feat(internal): add Thoth client and simple ASN checker

Signed-off-by: Xe Iaso <me@xeiaso.net>

* feat(thoth): cached ip to asn checker

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: go mod tidy

Signed-off-by: Xe Iaso <me@xeiaso.net>

* fix(thoth): minor testing fixups, ensure ASNChecker is Checker

Signed-off-by: Xe Iaso <me@xeiaso.net>

* feat(thoth): make ASNChecker instances

Signed-off-by: Xe Iaso <me@xeiaso.net>

* feat(thoth): add GeoIP checker

Signed-off-by: Xe Iaso <me@xeiaso.net>

* feat(thoth): store a thoth client in a context

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: refactor Checker type to its own package

Signed-off-by: Xe Iaso <me@xeiaso.net>

* test(thoth): add thoth mocking package, ignore context deadline exceeded errors

Signed-off-by: Xe Iaso <me@xeiaso.net>

* feat(thoth): pre-cache private ranges

Signed-off-by: Xe Iaso <me@xeiaso.net>

* feat(lib/policy/config): enable thoth ASNs and GeoIP checker parsing

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore(thoth): refactor to move checker creation to the checker files

Signed-off-by: Xe Iaso <me@xeiaso.net>

* feat(policy): enable thoth checks

Signed-off-by: Xe Iaso <me@xeiaso.net>

* feat(thothmock): test helper function for loading a mock thoth instance

Signed-off-by: Xe Iaso <me@xeiaso.net>

* feat: wire up Thoth, make thoth checks part of the default config

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: spelling

Signed-off-by: Xe Iaso <me@xeiaso.net>

* fix(thoth): mend staticcheck errors

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs(admin): add Thoth docs

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore(policy): update Thoth links in error messages

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs: update CHANGELOG

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: spelling

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore(docs/manifest): enable Thoth

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: add THOTH_INSECURE for contacting Thoth over plain TCP in extreme circumstances

Signed-off-by: Xe Iaso <me@xeiaso.net>

* test(thoth): use mock thoth when credentials aren't detected in the environment

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: spelling

Signed-off-by: Xe Iaso <me@xeiaso.net>

* fix(cmd/anubis): better warnings for half-configured Thoth setups

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs(botpolicies): link to Thoth geoip docs

Signed-off-by: Xe Iaso <me@xeiaso.net>

---------

Signed-off-by: Xe Iaso <me@xeiaso.net>

.github/actions/spelling/expect.txt

@@ -9,10 +9,13 @@ anubistest
 apk
 Applebot
 archlinux
+asnc
+asnchecker
+asns
+aspirational
 badregexes
 bdba
 berr
-betteralign
 bingbot
 bitcoin
 blogging
@@ -25,6 +28,7 @@ Brightbot
 broked
 Bytespider
 cachebuster
+cachediptoasn
 Caddyfile
 caninetools
 Cardyb
@@ -89,9 +93,14 @@ Fordola
 forgejo
 fsys
 fullchain
+gaissmai
 Galvus
+geoip
+geoipchecker
 gha
+gipc
 gitea
+godotenv
 goland
 gomod
 goodbot
@@ -101,6 +110,7 @@ goyaml
 GPG
 GPT
 gptbot
+grpcprom
 grw
 Hashcash
 hashrate
@@ -113,6 +123,7 @@ hostable
 htmlc
 htmx
 httpdebug
+Huawei
 hypertext
 iaskspider
 iat
@@ -120,11 +131,14 @@ ifm
 Imagesift
 imgproxy
 inp
+IPTo
+iptoasn
 iss
 isset
 ivh
 Jenomis
 JGit
+joho
 journalctl
 jshelter
 JWTs
@@ -164,7 +178,6 @@ mojeekbot
 mozilla
 nbf
 netsurf
-NFlag
 nginx
 nobots
 NONINFRINGEMENT
@@ -241,11 +254,14 @@ subrequest
 SVCNAME
 tagline
 tarballs
+tarrif
 techaro
 techarohq
 templ
 templruntime
 testarea
+thoth
+thothmock
 Tik
 Timpibot
 torproject
@@ -270,6 +286,7 @@ websecure
 websites
 Webzio
 wildbase
+withthothmock
 wordpress
 Workaround
 workdir