GCP Authentication filter server (https://blog.salrashid.dev/articles/2022/envoy_gcp_authn/ )

server_tmpl.yaml

admin:
  access_log_path: /dev/null
  address:
    socket_address:
      address: 127.0.0.1
      port_value: 9000
node:
  cluster: service_greeter
  id: test-id
static_resources:
  listeners:
  - name: listener_0
    address:
      socket_address: { address: 0.0.0.0, port_value: 10000 }
    filter_chains:
    - filters:
      - name: envoy.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
          stat_prefix: ingress_http
          codec_type: AUTO
          route_config:
            name: local_route
            virtual_hosts:
            - name: local_service
              domains: ["*"]
              routes:
              - match:
                  prefix: "/get"
                direct_response:
                  status: 200
                  body:
                    inline_string: "ok"          
          http_filters:
          - name: envoy.filters.http.jwt_authn
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.jwt_authn.v3.JwtAuthentication
              providers:
                google-jwt:
                  issuer: https://accounts.google.com
                  audiences:
                  - server.c.$PROJECT_ID.internal
                  remote_jwks:
                    http_uri:
                      uri: https://www.googleapis.com/oauth2/v3/certs
                      cluster: jwt.www.googleapis.com|443
                      timeout:
                        seconds: 5
                  from_headers:
                  - name: Authorization
                    value_prefix: "Bearer "
              rules:
              - match:
                  prefix: "/"
                requires:
                  provider_name: "google-jwt"
          - name: envoy.filters.http.router
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router
      transport_socket:
        name: envoy.transport_sockets.alts
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.transport_sockets.alts.v3.Alts
          handshaker_service: "169.254.169.254:8080"
          peer_service_accounts:
          - "$CLIENT_SERVICE_ACCOUNT"

  clusters:
  - name: jwt.www.googleapis.com|443
    type: LOGICAL_DNS
    dns_lookup_family: V4_ONLY
    connect_timeout: 2s
    lb_policy: ROUND_ROBIN
    load_assignment:
      cluster_name: service_httpbin
      endpoints:
      - lb_endpoints:
        - endpoint:
            address:
              socket_address:
                address: www.googleapis.com
                port_value: 443
    transport_socket:
      name: envoy.transport_sockets.tls
      typed_config:
        "@type": type.googleapis.com/envoy.extensions.transport_sockets.tls.v3.UpstreamTlsContext