Mill-ħajja ma' Kubernetes: Kif is-server HTTP ma ffavorixx lill-Ispanjoli

Rappreżentant tal-klijent tagħna, li l-munzell tal-applikazzjoni tiegħu jirrisjedi fil-cloud minn Microsoft (Azure), indirizza problema: reċentement, xi talbiet minn xi klijenti mill-Ewropa bdew jispiċċaw bi żball 400 (Talba ħażina). L-applikazzjonijiet kollha huma miktuba f'.NET, skjerati f'Kubernetes...

Waħda mill-applikazzjonijiet hija l-API, li permezz tagħha finalment jiġi t-traffiku kollu. Dan it-traffiku jinstema' mis-server HTTP kestrel, ikkonfigurat mill-klijent .NET u ospitat f'pod. Bil-debugging, konna xxurtjati fis-sens li kien hemm utent speċifiku li konsistentement riproduċi l-problema. Madankollu, kollox kien ikkumplikat mill-katina tat-traffiku:

L-iżball f'Ingress deher bħal dan:

{
   "number_fields":{
      "status":400,
      "request_time":0.001,
      "bytes_sent":465,
      "upstream_response_time":0,
      "upstream_retries":0,
      "bytes_received":2328
   },
   "stream":"stdout",
   "string_fields":{
      "ingress":"app",
      "protocol":"HTTP/1.1",
      "request_id":"f9ab8540407208a119463975afda90bc",
      "path":"/api/sign-in",
      "nginx_upstream_status":"400",
      "service":"app",
      "namespace":"production",
      "location":"/front",
      "scheme":"https",
      "method":"POST",
      "nginx_upstream_response_time":"0.000",
      "nginx_upstream_bytes_received":"120",
      "vhost":"api.app.example.com",
      "host":"api.app.example.com",
      "user":"",
      "address":"83.41.81.250",
      "nginx_upstream_addr":"10.240.0.110:80",
      "referrer":"https://api.app.example.com/auth/login?long_encrypted_header",
      "service_port":"http",
      "user_agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.121 Safari/537.36",
      "time":"2019-03-06T18:29:16+00:00",
      "content_kind":"cache-headers-not-present",
      "request_query":""
   },
   "timestamp":"2019-03-06 18:29:16",
   "labels":{
      "app":"nginx",
      "pod-template-generation":"6",
      "controller-revision-hash":"1682636041"
   },
   "namespace":"kube-nginx-ingress",
   "nsec":6726612,
   "source":"kubernetes",
   "host":"k8s-node-55555-0",
   "pod_name":"nginx-v2hcb",
   "container_name":"nginx",
   "boolean_fields":{}
}

Fl-istess ħin, Kestrel ta:

HTTP/1.1 400 Bad Request
Connection: close
Date: Wed, 06 Mar 2019 12:34:20 GMT
Server: Kestrel
Content-Length: 0

Anke b'verożità massima, l-iżball Kestrel kien fih estremament ftit informazzjoni utli:

{
   "number_fields":{"ThreadId":76},
   "stream":"stdout",
   "string_fields":{
      "EventId":"{"Id"=>17, "Name"=>"ConnectionBadRequest"}",
      "SourceContext":"Microsoft.AspNetCore.Server.Kestrel",
      "ConnectionId":"0HLL2VJSST5KV",
      "@mt":"Connection id "{ConnectionId}" bad request data: "{message}"",
      "@t":"2019-03-07T13:06:48.1449083Z",
      "@x":"Microsoft.AspNetCore.Server.Kestrel.Core.BadHttpRequestException: Malformed request: invalid headers.n   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.Http1Connection.TryParseRequest(ReadResult result, Boolean& endConnection)n   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.<ProcessRequestsAsync>d__185`1.MoveNext()",
      "message":"Malformed request: invalid headers."
   },
   "timestamp":"2019-03-07 13:06:48",
   "labels":{
      "pod-template-hash":"2368795483",
      "service":"app"
   },
   "namespace":"production",
   "nsec":145341848,
   "source":"kubernetes",
   "host":"k8s-node-55555-1",
   "pod_name":"app-67bdcf98d7-mhktx",
   "container_name":"app",
   "boolean_fields":{}
}

Jidher li tcpdump biss se jgħin biex issolvi din il-problema... imma se nirrepeti dwar il-katina tat-traffiku:

Investigazzjoni

Ovvjament, huwa aħjar li tisma 't-traffiku fuq dak in-nodu speċifiku, fejn Kubernetes uża pod: il-volum tad-dump se jkun tali li jkun possibbli li ssib mill-inqas xi ħaġa pjuttost malajr. U tabilħaqq, meta eżaminatha, ġie nnutat il-qafas li ġej:

GET /back/user HTTP/1.1
Host: api.app.example.com
X-Request-ID: 27ceb14972da8c21a8f92904b3eff1e5
X-Real-IP: 83.41.81.250
X-Forwarded-For: 83.41.81.250
X-Forwarded-Host: api.app.example.com
X-Forwarded-Port: 443
X-Forwarded-Proto: https
X-Original-URI: /front/back/user
X-Scheme: https
X-Original-Forwarded-For: 83.41.81.250
X-Nginx-Geo-Client-Country: Spain
X-Nginx-Geo-Client-City: M.laga
Accept-Encoding: gzip
CF-IPCountry: ES
CF-RAY: 4b345cfd1c4ac691-MAD
CF-Visitor: {"scheme":"https"}
pragma: no-cache
cache-control: no-cache
accept: application/json, text/plain, */*
origin: https://app.example.com
user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.119 Safari/537.36
referer: https://app.example.com/auth/login
accept-language: en-US,en;q=0.9,en-GB;q=0.8,pl;q=0.7
cookie: many_encrypted_cookies; .AspNetCore.Identity.Application=something_encrypted; 
CF-Connecting-IP: 83.41.81.250
True-Client-IP: 83.41.81.250
CDN-Loop: cloudflare

HTTP/1.1 400 Bad Request
Connection: close
Date: Wed, 06 Mar 2019 12:34:20 GMT
Server: Kestrel
Content-Length: 0

Wara spezzjoni aktar mill-qrib tal-miżbla, il-kelma ġiet innutata M.laga. Huwa faċli li wieħed isib li m'hemm l-ebda belt M.laga fi Spanja (iżda hemm Malaga). Ħadna din l-idea, ħares lejn il-konfigurazzjonijiet tal-Ingress, fejn rajna dik imdaħħla xahar ilu (fuq talba tal-klijent) snippet "li ma jagħmilx ħsara".:

    ingress.kubernetes.io/configuration-snippet: |
      proxy_set_header X-Nginx-Geo-Client-Country $geoip_country_name;
      proxy_set_header X-Nginx-Geo-Client-City $geoip_city;

Wara li ddiżattiva t-twassil ta 'dawn l-headers, kollox sar tajjeb! (Malajr deher ċar li l-applikazzjoni nnifisha m'għadhiex teħtieġ dawn l-intestaturi.)

Issa ejja nħarsu lejn il-problema b'mod aktar ġenerali. Jista 'jiġi riprodott faċilment ġewwa l-applikazzjoni billi tagħmel talba telnet lil localhost:80:

GET /back/user HTTP/1.1
Host: api.app.example.com
cache-control: no-cache
accept: application/json, text/plain, */*
origin: https://app.example.com
Cookie: test=Desiree

... prospetti 401 Unauthorized, kif mistenni. X'jiġri jekk nagħmlu:

GET /back/user HTTP/1.1
Host: api.app.example.com
cache-control: no-cache
accept: application/json, text/plain, */*
origin: https://app.example.com
Cookie: test=Désirée

?

Se jirritorna 400 Bad request — fir-reġistru tal-applikazzjoni se nirċievu żball li diġà huwa familjari għalina:

{
   "@t":"2019-03-31T12:59:54.3746446Z",
   "@mt":"Connection id "{ConnectionId}" bad request data: "{message}"",
   "@x":"Microsoft.AspNetCore.Server.Kestrel.Core.BadHttpRequestException: Malformed request: invalid headers.n   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.Http1Connection.TryParseRequest(ReadResult result, Boolean& endConnection)n   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.<ProcessRequestsAsync>d__185`1.MoveNext()",
   "ConnectionId":"0HLLLR1J974L9",
   "message":"Malformed request: invalid headers.",
   "EventId":{
      "Id":17,
      "Name":"ConnectionBadRequest"
   },
   "SourceContext":"Microsoft.AspNetCore.Server.Kestrel",
   "ThreadId":71
}

Riżultati ta '

Speċifikament Kestrel ma tistax ipproċessa b'mod korrett headers HTTP bil-karattri korretti f'UTF-8, li jinsabu fl-ismijiet ta 'numru pjuttost kbir ta' bliet.

Fattur addizzjonali fil-każ tagħna huwa li l-klijent bħalissa ma jippjanax li jibdel l-implimentazzjoni ta 'Kestrel fl-applikazzjoni. Madankollu, kwistjonijiet f'AspNetCore innifsu (No.4318, No.7707) jgħidu li dan mhux se jgħin...

Fil-qosor: in-nota m'għadhiex dwar il-problemi speċifiċi ta 'Kestrel jew UTF-8 (fl-2019?!), Imma dwar il-fatt li mindfulness u studju konsistenti Kull pass li tieħu waqt li tkun qed tfittex problemi illum jew għada se jagħti l-frott. Ix-xorti t-tajba!

PS

Aqra wkoll fuq il-blog tagħna:

• «6 bugs tas-sistema divertenti fl-operat ta' Kubernetes [u s-soluzzjoni tagħhom]»;
• «Suġġerimenti u tricks ta' Kubernetes: paġni ta' żbalji personalizzati f'NGINX Ingress»;
• «Ħarsa ġenerali u paragun tal-kontrolluri Ingress għal Kubernetes»;
• «Monitoraġġ tal-pings bejn in-nodi Kubernetes - ir-riċetta tagħna»;
• «3 każijiet mhux tas-soltu dwar is-subsistema tan-netwerk Linux".

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