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>

data/botPolicies.yaml

@@ -51,6 +51,29 @@ bots:
   #     report_as: 4    # lie to the operator
   #     algorithm: slow # intentionally waste CPU cycles and time
 
+  # Requires a subscription to Thoth to use, see
+  # https://anubis.techaro.lol/docs/admin/thoth#geoip-based-filtering
+  - name: countries-with-aggressive-scrapers
+    action: WEIGH
+    geoip:
+      counties:
+        - BR
+        - CN
+    weight:
+      adjust: 10
+
+  # Requires a subscription to Thoth to use, see
+  # https://anubis.techaro.lol/docs/admin/thoth#asn-based-filtering
+  - name: aggressive-asns-without-functional-abuse-contact
+    action: WEIGH
+    asns:
+      match:
+        - 13335 # Cloudflare
+        - 136907 # Huawei Cloud
+        - 45102 # Alibaba Cloud
+    weight:
+      adjust: 10
+
   # Generic catchall rule
   - name: generic-browser
     user_agent_regex: >-