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Awtentika f'Kubernetes billi tuża GitHub OAuth u Dex

Nippreżenta għall-attenzjoni tiegħek tutorja biex tiġġenera aċċess għal cluster Kubernetes billi tuża Dex, dex-k8s-authenticator u GitHub.

Awtentika f'Kubernetes billi tuża GitHub OAuth u Dex
Meme lokali miċ-chat ta' Kubernetes bil-lingwa Russa Telegramma

Introduzzjoni

Aħna nużaw Kubernetes biex noħolqu ambjenti dinamiċi għat-tim tal-iżvilupp u l-QA. Allura rridu nagħtuhom aċċess għall-cluster kemm għad-dashboard kif ukoll għall-kubectl. B'differenza OpenShift, vanilla Kubernetes m'għandux awtentikazzjoni nattiva, għalhekk nużaw għodod ta 'partijiet terzi għal dan.

F'din il-konfigurazzjoni nużaw:

  • dex-k8s-awtentikatur  — applikazzjoni tal-web biex tiġġenera kubectl config
  • dex — Fornitur tal-OpenID Connect
  • GitHub - sempliċement għax nużaw GitHub fil-kumpanija tagħna

Ippruvajna nużaw Google OIDC, imma sfortunatament aħna falliet biex nibdew bi gruppi, għalhekk l-integrazzjoni ma 'GitHub addattatna pjuttost tajjeb. Mingħajr mapping tal-grupp, mhux se jkun possibbli li jinħolqu politiki RBAC bbażati fuq gruppi.

Allura, kif jaħdem il-proċess ta' awtorizzazzjoni Kubernetes tagħna f'rappreżentazzjoni viżiva:

Awtentika f'Kubernetes billi tuża GitHub OAuth u Dex
Proċess ta' awtorizzazzjoni

Ftit aktar dettall u punt b'punt:

  1. L-utent jidħol f'dex-k8s-authenticator (login.k8s.example.com)
  2. dex-k8s-authenticator jgħaddi t-talba lil Dex (dex.k8s.example.com)
  3. Dex jidderieġi mill-ġdid lejn il-paġna tal-login ta' GitHub
  4. GitHub jiġġenera l-informazzjoni meħtieġa dwar l-awtorizzazzjoni u jibgħatha lura lil Dex
  5. Dex jgħaddi l-informazzjoni riċevuta lil dex-k8s-authenticator
  6. L-utent jirċievi token OIDC minn GitHub
  7. dex-k8s-authenticator iżid token ma' kubeconfig
  8. kubectl jgħaddi t-token lil KubeAPIServer
  9. KubeAPIServer jirritorna aċċessi għal kubectl ibbażati fuq it-token mgħoddi
  10. L-utent ikollu aċċess minn kubectl

Azzjonijiet preparatorji

Naturalment, diġà għandna cluster Kubernetes installat (k8s.example.com), u jiġi wkoll b'HELM installat minn qabel. Għandna wkoll organizzazzjoni fuq GitHub (super-org).
Jekk m'għandekx HELM, installah sempliċi ħafna.

L-ewwel irridu nwaqqfu GitHub.

Mur fil-paġna tas-settings tal-organizzazzjoni, (https://github.com/organizations/super-org/settings/applications) u oħloq applikazzjoni ġdida (App OAuth Awtorizzata):
Awtentika f'Kubernetes billi tuża GitHub OAuth u Dex
Ħolqien ta' applikazzjoni ġdida fuq GitHub

Imla l-oqsma bl-URLs meħtieġa, pereżempju:

  • URL tal-paġna ewlenija: https://dex.k8s.example.com
  • URL ta' callback ta' awtorizzazzjoni: https://dex.k8s.example.com/callback

Oqgħod attent bil-links, huwa importanti li ma titlifx slashes.

Bi tweġiba għal formola mimlija, GitHub se jiġġenera Client ID и Client secret, żommhom f'post sigur, se jkunu utli għalina (per eżempju, nużaw Vault għall-ħażna tas-sigrieti):

Client ID: 1ab2c3d4e5f6g7h8
Client secret: 98z76y54x32w1

Ipprepara rekords DNS għal sottodominji login.k8s.example.com и dex.k8s.example.com, kif ukoll ċertifikati SSL għad-dħul.

Ejja noħolqu ċertifikati SSL:

cat <<EOF | kubectl create -f -
apiVersion: certmanager.k8s.io/v1alpha1
kind: Certificate
metadata:
  name: cert-auth-dex
  namespace: kube-system
spec:
  secretName: cert-auth-dex
  dnsNames:
    - dex.k8s.example.com
  acme:
    config:
    - http01:
        ingressClass: nginx
      domains:
      - dex.k8s.example.com
  issuerRef:
    name: le-clusterissuer
    kind: ClusterIssuer
---
apiVersion: certmanager.k8s.io/v1alpha1
kind: Certificate
metadata:
  name: cert-auth-login
  namespace: kube-system
spec:
  secretName: cert-auth-login
  dnsNames:
    - login.k8s.example.com
  acme:
    config:
    - http01:
        ingressClass: nginx
      domains:
      - login.k8s.example.com
  issuerRef:
    name: le-clusterissuer
    kind: ClusterIssuer
EOF
kubectl describe certificates cert-auth-dex -n kube-system
kubectl describe certificates cert-auth-login -n kube-system

ClusterIssuer bit-titolu le-clusterissuer għandha diġà teżisti, imma jekk le, oħloqha billi tuża HELM:

helm install --namespace kube-system -n cert-manager stable/cert-manager
cat << EOF | kubectl create -f -
apiVersion: certmanager.k8s.io/v1alpha1
kind: ClusterIssuer
metadata:
  name: le-clusterissuer
  namespace: kube-system
spec:
  acme:
    server: https://acme-v02.api.letsencrypt.org/directory
    email: [email protected]
    privateKeySecretRef:
      name: le-clusterissuer
    http01: {}
EOF

Konfigurazzjoni KubeAPIServer

Biex kubeAPIServer jaħdem, trid tikkonfigura l-OIDC u taġġorna l-cluster:

kops edit cluster
...
  kubeAPIServer:
    anonymousAuth: false
    authorizationMode: RBAC
    oidcClientID: dex-k8s-authenticator
    oidcGroupsClaim: groups
    oidcIssuerURL: https://dex.k8s.example.com/
    oidcUsernameClaim: email
kops update cluster --yes
kops rolling-update cluster --yes

Aħna nużaw kops għall-iskjerament ta 'clusters, iżda dan jaħdem bl-istess mod għal maniġers oħra tal-clusters.

Konfigurazzjoni Dex u dex-k8s-authenticator

Biex Dex jaħdem, jeħtieġ li jkollok ċertifikat u ċavetta mill-kaptan tal-Kubernetes, ejja nġibuha minn hemm:

sudo cat /srv/kubernetes/ca.{crt,key}
-----BEGIN CERTIFICATE-----
AAAAAAAAAAABBBBBBBBBBCCCCCC
-----END CERTIFICATE-----
-----BEGIN RSA PRIVATE KEY-----
DDDDDDDDDDDEEEEEEEEEEFFFFFF
-----END RSA PRIVATE KEY-----

Ejja nikklonu r-repożitorju ta' dex-k8s-authenticator:

git clone [email protected]:mintel/dex-k8s-authenticator.git
cd dex-k8s-authenticator/

Bl-użu ta 'fajls ta' valuri, nistgħu nikkonfiguraw b'mod flessibbli varjabbli għal tagħna Ċarts HELM.

Ejja niddeskrivu l-konfigurazzjoni għal Dex:

cat << EOF > values-dex.yml
global:
  deployEnv: prod
tls:
  certificate: |-
    -----BEGIN CERTIFICATE-----
    AAAAAAAAAAABBBBBBBBBBCCCCCC
    -----END CERTIFICATE-----
  key: |-
    -----BEGIN RSA PRIVATE KEY-----
    DDDDDDDDDDDEEEEEEEEEEFFFFFF
    -----END RSA PRIVATE KEY-----
ingress:
  enabled: true
  annotations:
    kubernetes.io/ingress.class: nginx
    kubernetes.io/tls-acme: "true"
  path: /
  hosts:
    - dex.k8s.example.com
  tls:
    - secretName: cert-auth-dex
      hosts:
        - dex.k8s.example.com
serviceAccount:
  create: true
  name: dex-auth-sa
config: |
  issuer: https://dex.k8s.example.com/
  storage: # https://github.com/dexidp/dex/issues/798
    type: sqlite3
    config:
      file: /var/dex.db
  web:
    http: 0.0.0.0:5556
  frontend:
    theme: "coreos"
    issuer: "Example Co"
    issuerUrl: "https://example.com"
    logoUrl: https://example.com/images/logo-250x25.png
  expiry:
    signingKeys: "6h"
    idTokens: "24h"
  logger:
    level: debug
    format: json
  oauth2:
    responseTypes: ["code", "token", "id_token"]
    skipApprovalScreen: true
  connectors:
  - type: github
    id: github
    name: GitHub
    config:
      clientID: $GITHUB_CLIENT_ID
      clientSecret: $GITHUB_CLIENT_SECRET
      redirectURI: https://dex.k8s.example.com/callback
      orgs:
      - name: super-org
        teams:
        - team-red
  staticClients:
  - id: dex-k8s-authenticator
    name: dex-k8s-authenticator
    secret: generatedLongRandomPhrase
    redirectURIs:
      - https://login.k8s.example.com/callback/
envSecrets:
  GITHUB_CLIENT_ID: "1ab2c3d4e5f6g7h8"
  GITHUB_CLIENT_SECRET: "98z76y54x32w1"
EOF

U għal dex-k8s-authenticator:

cat << EOF > values-auth.yml
global:
  deployEnv: prod
dexK8sAuthenticator:
  clusters:
  - name: k8s.example.com
    short_description: "k8s cluster"
    description: "Kubernetes cluster"
    issuer: https://dex.k8s.example.com/
    k8s_master_uri: https://api.k8s.example.com
    client_id: dex-k8s-authenticator
    client_secret: generatedLongRandomPhrase
    redirect_uri: https://login.k8s.example.com/callback/
    k8s_ca_pem: |
      -----BEGIN CERTIFICATE-----
      AAAAAAAAAAABBBBBBBBBBCCCCCC
      -----END CERTIFICATE-----
ingress:
  enabled: true
  annotations:
    kubernetes.io/ingress.class: nginx
    kubernetes.io/tls-acme: "true"
  path: /
  hosts:
    - login.k8s.example.com
  tls:
    - secretName: cert-auth-login
      hosts:
        - login.k8s.example.com
EOF

Installa Dex u dex-k8s-authenticator:

helm install -n dex --namespace kube-system --values values-dex.yml charts/dex
helm install -n dex-auth --namespace kube-system --values values-auth.yml charts/dex-k8s-authenticator

Ejja niċċekkja l-funzjonalità tas-servizzi (Dex għandu jirritorna l-kodiċi 400, u dex-k8s-authenticator għandu jirritorna l-kodiċi 200):

curl -sI https://dex.k8s.example.com/callback | head -1
HTTP/2 400
curl -sI https://login.k8s.example.com/ | head -1
HTTP/2 200

Konfigurazzjoni RBAC

Aħna noħolqu ClusterRole għall-grupp, fil-każ tagħna b'aċċess għall-qari biss:

cat << EOF | kubectl create -f -
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: cluster-read-all
rules:
  -
    apiGroups:
      - ""
      - apps
      - autoscaling
      - batch
      - extensions
      - policy
      - rbac.authorization.k8s.io
      - storage.k8s.io
    resources:
      - componentstatuses
      - configmaps
      - cronjobs
      - daemonsets
      - deployments
      - events
      - endpoints
      - horizontalpodautoscalers
      - ingress
      - ingresses
      - jobs
      - limitranges
      - namespaces
      - nodes
      - pods
      - pods/log
      - pods/exec
      - persistentvolumes
      - persistentvolumeclaims
      - resourcequotas
      - replicasets
      - replicationcontrollers
      - serviceaccounts
      - services
      - statefulsets
      - storageclasses
      - clusterroles
      - roles
    verbs:
      - get
      - watch
      - list
  - nonResourceURLs: ["*"]
    verbs:
      - get
      - watch
      - list
  - apiGroups: [""]
    resources: ["pods/exec"]
    verbs: ["create"]
EOF

Ejja noħolqu konfigurazzjoni għal ClusterRoleBinding:

cat <<EOF | kubectl create -f -
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: dex-cluster-auth
  namespace: kube-system
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-read-all
subjects:
  kind: Group
  name: "super-org:team-red"
EOF

Issa aħna lesti għall-ittestjar.

Testijiet

Mur fil-paġna tal-login (https://login.k8s.example.com) u illoggja billi tuża l-kont GitHub tiegħek:

Awtentika f'Kubernetes billi tuża GitHub OAuth u Dex
Il-paġna tal-login

Awtentika f'Kubernetes billi tuża GitHub OAuth u Dex
Il-paġna tal-login rediretta lejn GitHub

Awtentika f'Kubernetes billi tuża GitHub OAuth u Dex
 Segwi l-istruzzjonijiet iġġenerati biex tikseb aċċess

Wara li nikkopja-pejst mill-paġna web, nistgħu nużaw kubectl biex niġġestixxu r-riżorsi tal-cluster tagħna:

kubectl get po
NAME                READY   STATUS    RESTARTS   AGE
mypod               1/1     Running   0          3d

kubectl delete po mypod
Error from server (Forbidden): pods "mypod" is forbidden: User "[email protected]" cannot delete pods in the namespace "default"

U jaħdem, l-utenti kollha ta 'GitHub fl-organizzazzjoni tagħna jistgħu jaraw ir-riżorsi u jidħlu fil-miżwed, iżda m'għandhomx drittijiet biex jibdluhom.

Sors: www.habr.com

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