How does linkerd-proxy do service discovery for http request?

[copbint]

I'm trying to run linkerd-proxy without kubernetes and docker, and encounterd some problems, any suggestions would be really appreciated.

What did I do:

1. prepare two node:

ubuntu1: 192.168.56.107
ubuntu2: 192.168.56.108

2. run linkerd2-mock-dst on ubuntu1
   ./linkerd2-mock-dst --endpoints ubuntu2.servic:8080=192.168.56.108:8080

3. set iptables rule on ubuntu1(only output direction rules so far):

iptables -t nat -A OUTPUT -p tcp  -m owner --uid-owner 1001  -j RETURN
iptables -t nat -A OUTPUT -p tcp  --dport 8080 -j REDIRECT --to-port 4140

4. run linkerd-proxy on ubuntu1, with a user(id is 1001):

export LINKERD2_PROXY_TAP_DISABLED=true
export LINKERD2_PROXY_IDENTITY_DISABLED=true
export LINKERD2_PROXY_DESTINATION_SVC_ADDR=192.168.56.107:8086
export LINKERD2_PROXY_LOG=debug
export LINKERD2_PROXY_ADMIN_LISTEN_ADDR=127.0.0.1:4191
export LINKERD2_PROXY_OUTBOUND_LISTEN_ADDR=127.0.0.1:4140
export LINKERD2_PROXY_INBOUND_LISTEN_ADDR=127.0.0.1:4143
export LINKERD2_PROXY_DESTINATION_PROFILE_NETWORKS=10.0.0.0/8,100.64.0.0/10,172.16.0.0/12,192.168.0.0/16
./linkerd-proxy   

5. start a http server on ubuntu2, listen on :192.168.56.108:8080

6. add a recored in /etc/hosts of ubuntu1, to avoid Could not resolve host: ubuntu2.service:
   192.168.56.108 ubuntu2.service

7. use curl to connect http server from ubuntu1.

8. the request succeed, but something is wrong accroding to the log:
   log of linkerd2-mock-dst:

Nov 02 09:40:12.028  INFO request{headers={"te": "trailers", "content-type": "application/grpc"}}:stream_overrides{dst=Dst { name: "192.168.56.108", port: 8080 }}: linkerd2_mock_dst::destination: Does not exist

log of linkerd-proxy :

[     9.388539221s] DEBUG ThreadId(03) outbound: linkerd2_cache: services=0 dropped=0
[     9.388675052s] DEBUG ThreadId(03) outbound: linkerd2_cache: Caching new service
[     9.389391154s] DEBUG ThreadId(02) dst: tower::balance::p2c::service: updating from discover
[     9.389528319s] DEBUG ThreadId(02) dst: linkerd2_proxy_resolve::recover: recovering err=end of stream reached
[     9.390486231s] DEBUG ThreadId(02) dst:h2: h2::codec::framed_write: send; frame=Headers { stream_id: StreamId(1), flags: (0x4: END_HEADERS) }
[     9.390729597s] DEBUG ThreadId(02) dst:h2: h2::codec::framed_write: send; frame=Data { stream_id: StreamId(1) }
[     9.390856777s] DEBUG ThreadId(02) dst:h2: h2::codec::framed_write: send; frame=Data { stream_id: StreamId(1), flags: (0x1: END_STREAM) }
[     9.395847838s] DEBUG ThreadId(06) dst:h2: h2::codec::framed_read: received; frame=Headers { stream_id: StreamId(1), flags: (0x4: END_HEADERS) }
[     9.396445276s] DEBUG ThreadId(06) dst:h2: h2::codec::framed_read: received; frame=Headers { stream_id: StreamId(1), flags: (0x5: END_HEADERS | END_STREAM) }
[     9.397284379s] DEBUG ThreadId(06) outbound: linkerd2_service_profiles::default: Handling rejected discovery
[     9.397966771s] DEBUG ThreadId(06) outbound: linkerd2_proxy_transport::prefix: Buffering prefix capacity=8192
[     9.398563120s] DEBUG ThreadId(06) outbound: linkerd2_proxy_http::detect: Handling as HTTP
[     9.399578306s] DEBUG ThreadId(05) outbound:http{v=1.x}:logical{dst=192.168.56.108:8080}:concrete: linkerd2_app_outbound::resolve: Synthesizing endpoint error=status: InvalidArgument, message: "Discovery rejected", details: [], metadata: MetadataMap { headers: {} } addr=192.168.56.108:8080
[     9.400671233s] DEBUG ThreadId(06) outbound:accept{peer.addr=192.168.56.107:39734 target.addr=192.168.56.108:8080}: hyper::proto::h1::io: read 84 bytes
[     9.400915100s] DEBUG ThreadId(05) outbound:http{v=1.x}:logical{dst=192.168.56.108:8080}:concrete: tower::balance::p2c::service: updating from discover
[     9.401157334s] DEBUG ThreadId(05) tower::balance::p2c::service: updating from discover
[     9.401571295s]  WARN ThreadId(02) outbound:http{v=1.x}:logical{dst=192.168.56.108:8080}:concrete: linkerd2_proxy_discover::buffer: Discovery stream ended!
[     9.401723780s] DEBUG ThreadId(02) tower::balance::p2c::service: updating from discover
[     9.401926303s] DEBUG ThreadId(02) outbound:http{v=1.x}:logical{dst=192.168.56.108:8080}:concrete:endpoint{peer.addr=192.168.56.108:8080}: linkerd2_proxy_http::client: Building HTTP client settings=Http1
[     9.402299711s] DEBUG ThreadId(02) outbound:http{v=1.x}:logical{dst=192.168.56.108:8080}:concrete: tower::balance::p2c::service: updating from discover
[     9.402800879s] DEBUG ThreadId(06) outbound:accept{peer.addr=192.168.56.107:39734 target.addr=192.168.56.108:8080}: hyper::proto::h1::io: parsed 3 headers
[     9.403334129s] DEBUG ThreadId(06) outbound:accept{peer.addr=192.168.56.107:39734 target.addr=192.168.56.108:8080}: hyper::proto::h1::conn: incoming body is empty
[     9.404175818s] DEBUG ThreadId(02) outbound:http{v=1.x}:logical{dst=192.168.56.108:8080}:concrete: tower::balance::p2c::service: updating from discover
[     9.404515036s] DEBUG ThreadId(02) outbound:http{v=1.x}:logical{dst=192.168.56.108:8080}:concrete:endpoint{peer.addr=192.168.56.108:8080}:http1: linkerd2_proxy_http::client: method=GET uri=http://ubuntu2.service:8080/ version=HTTP/1.1
[     9.404627478s] DEBUG ThreadId(02) outbound:http{v=1.x}:logical{dst=192.168.56.108:8080}:concrete:endpoint{peer.addr=192.168.56.108:8080}:http1: linkerd2_proxy_http::client: headers={"host": "ubuntu2.service:8080", "user-agent": "curl/7.68.0", "accept": "*/*", "l5d-dst-canonical": "192.168.56.108:8080"}
[     9.404761452s] DEBUG ThreadId(02) outbound:http{v=1.x}:logical{dst=192.168.56.108:8080}:concrete:endpoint{peer.addr=192.168.56.108:8080}:http1: linkerd2_proxy_http::h1: Caching new client use_absolute_form=false
[     9.405335535s] DEBUG ThreadId(02) outbound:http{v=1.x}:logical{dst=192.168.56.108:8080}:concrete:endpoint{peer.addr=192.168.56.108:8080}:http1: linkerd2_app_outbound::prevent_loop: addr=192.168.56.108:8080 self.port=4140
[     9.405500424s] DEBUG ThreadId(02) outbound:http{v=1.x}:logical{dst=192.168.56.108:8080}:concrete:endpoint{peer.addr=192.168.56.108:8080}:http1: linkerd2_proxy_transport::tls::client: peer.identity=None(NotProvidedByServiceDiscovery)
[     9.405594798s] DEBUG ThreadId(02) outbound:http{v=1.x}:logical{dst=192.168.56.108:8080}:concrete:endpoint{peer.addr=192.168.56.108:8080}:http1: linkerd2_proxy_transport::connect: Connecting peer.addr=192.168.56.108:8080
[     9.406377300s] DEBUG ThreadId(03) outbound:http{v=1.x}:logical{dst=192.168.56.108:8080}:concrete:endpoint{peer.addr=192.168.56.108:8080}:http1: linkerd2_proxy_transport::connect: Connected local.addr=192.168.56.107:39736 keepalive=None
[     9.406556493s] DEBUG ThreadId(03) outbound:http{v=1.x}:logical{dst=192.168.56.108:8080}:concrete:endpoint{peer.addr=192.168.56.108:8080}:http1: linkerd2_proxy_transport::metrics: client connection open
[     9.407723479s] DEBUG ThreadId(03) hyper::proto::h1::io: flushed 124 bytes
[     9.408858250s] DEBUG ThreadId(03) hyper::proto::h1::io: read 1424 bytes
[     9.409084756s] DEBUG ThreadId(03) hyper::proto::h1::io: parsed 4 headers
[     9.409184749s] DEBUG ThreadId(03) hyper::proto::h1::conn: incoming body is content-length (1268 bytes)
[     9.409327984s] DEBUG ThreadId(03) hyper::proto::h1::conn: incoming body completed
[     9.410350447s] DEBUG ThreadId(06) outbound:accept{peer.addr=192.168.56.107:39734 target.addr=192.168.56.108:8080}: hyper::proto::h1::io: flushed 1424 bytes
[     9.410675031s] DEBUG ThreadId(05) outbound:accept{peer.addr=192.168.56.107:39734 target.addr=192.168.56.108:8080}: hyper::proto::h1::io: read 0 bytes
[     9.410785064s] DEBUG ThreadId(05) outbound:accept{peer.addr=192.168.56.107:39734 target.addr=192.168.56.108:8080}: hyper::proto::h1::conn: read eof
[     9.411114240s] DEBUG ThreadId(05) outbound:accept{peer.addr=192.168.56.107:39734 target.addr=192.168.56.108:8080}: linkerd2_app_core::serve: Connection closed

It means linkerd-proxy use destination ip and port (192.168.56.108:8080) to do service discovery request, but not domain name in the http header Host(ubuntu2.service:8080).

Thanks very much!