.. _install_sandboxes_front_proxy:
Front proxy
===========
.. sidebar:: Requirements
.. include:: _include/docker-env-setup-link.rst
:ref:`curl <start_sandboxes_setup_curl>`
Used to make ``HTTP`` requests.
To get a flavor of what Envoy has to offer as a front proxy, we are releasing a
`docker compose <https://docs.docker.com/compose/>`_ sandbox that deploys a front Envoy and a
couple of services (simple Flask apps) colocated with a running service Envoy.
The three containers will be deployed inside a virtual network called ``envoymesh``.
Below you can see a graphic showing the docker compose deployment:
.. image:: /_static/docker_compose_front_proxy.svg
:width: 100%
All incoming requests are routed via the front Envoy, which is acting as a reverse proxy sitting on
the edge of the ``envoymesh`` network. Port ``8080``, ``8443``, and ``8001`` are exposed by docker
compose (see :download:`docker-compose.yaml <_include/front-proxy/docker-compose.yaml>`) to handle
``HTTP``, ``HTTPS`` calls to the services and requests to ``/admin`` respectively.
Moreover, notice that all traffic routed by the front Envoy to the service containers is actually
routed to the service Envoys (routes setup in :download:`front-envoy.yaml <_include/front-proxy/front-envoy.yaml>`).
In turn the service Envoys route the request to the Flask app via the loopback
address (routes setup in :download:`service-envoy.yaml <_include/front-proxy/service-envoy.yaml>`). This
setup illustrates the advantage of running service Envoys collocated with your services: all
requests are handled by the service Envoy, and efficiently routed to your services.
Step 1: Start all of our containers
***********************************
Change to the ``examples/front-proxy`` directory.
.. code-block:: console
$ pwd
envoy/examples/front-proxy
$ docker-compose build --pull
$ docker-compose up -d
$ docker-compose ps
Name Command State Ports
----------------------------------------------------------------------------------------------------------------------------------------------------
front-proxy_front-envoy_1 /docker-entrypoint.sh /bin ... Up 10000/tcp, 0.0.0.0:8080->8080/tcp, 0.0.0.0:8001->8001/tcp, 0.0.0.0:8443->8443/tcp
front-proxy_service1_1 /bin/sh -c /usr/local/bin/ ... Up 10000/tcp
front-proxy_service2_1 /bin/sh -c /usr/local/bin/ ... Up 10000/tcp
Step 2: Test Envoy's routing capabilities
*****************************************
You can now send a request to both services via the ``front-envoy``.
For ``service1``:
.. code-block:: console
$ curl -v localhost:8080/service/1
* Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 8080 (#0)
> GET /service/1 HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 200 OK
< content-type: text/html; charset=utf-8
< content-length: 92
< server: envoy
< date: Mon, 06 Jul 2020 06:20:00 GMT
< x-envoy-upstream-service-time: 2
<
Hello from behind Envoy (service 1)! hostname: 36418bc3c824 resolvedhostname: 192.168.160.4
For ``service2``:
.. code-block:: console
$ curl -v localhost:8080/service/2
* Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 8080 (#0)
> GET /service/2 HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 200 OK
< content-type: text/html; charset=utf-8
< content-length: 92
< server: envoy
< date: Mon, 06 Jul 2020 06:23:13 GMT
< x-envoy-upstream-service-time: 2
<
Hello from behind Envoy (service 2)! hostname: ea6165ee4fee resolvedhostname: 192.168.160.2
Notice that each request, while sent to the front Envoy, was correctly routed to the respective
application.
We can also use ``HTTPS`` to call services behind the front Envoy. For example, calling ``service1``:
.. code-block:: console
$ curl https://localhost:8443/service/1 -k -v
* Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 8443 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
* successfully set certificate verify locations:
* CAfile: /etc/ssl/cert.pem
CApath: none
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
* TLSv1.2 (IN), TLS handshake, Server hello (2):
* TLSv1.2 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
* TLSv1.2 (IN), TLS handshake, Server finished (14):
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
* TLSv1.2 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (OUT), TLS handshake, Finished (20):
* TLSv1.2 (IN), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (IN), TLS handshake, Finished (20):
* SSL connection using TLSv1.2 / ECDHE-RSA-CHACHA20-POLY1305
* ALPN, server did not agree to a protocol
* Server certificate:
* subject: CN=front-envoy
* start date: Jul 5 15:18:44 2020 GMT
* expire date: Jul 5 15:18:44 2021 GMT
* issuer: CN=front-envoy
* SSL certificate verify result: self signed certificate (18), continuing anyway.
> GET /service/1 HTTP/1.1
> Host: localhost:8443
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 200 OK
< content-type: text/html; charset=utf-8
< content-length: 92
< server: envoy
< date: Mon, 06 Jul 2020 06:17:14 GMT
< x-envoy-upstream-service-time: 3
<
Hello from behind Envoy (service 1)! hostname: 36418bc3c824 resolvedhostname: 192.168.160.4
Step 3: Test Envoy's load balancing capabilities
************************************************
Now let's scale up our ``service1`` nodes to demonstrate the load balancing abilities of Envoy:
.. code-block:: console
$ docker-compose scale service1=3
Creating and starting example_service1_2 ... done
Creating and starting example_service1_3 ... done
Now if we send a request to ``service1`` multiple times, the front Envoy will load balance the
requests by doing a round robin of the three ``service1`` machines:
.. code-block:: console
$ curl -v localhost:8080/service/1
* Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 8080 (#0)
> GET /service/1 HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 200 OK
< content-type: text/html; charset=utf-8
< content-length: 92
< server: envoy
< date: Mon, 06 Jul 2020 06:21:47 GMT
< x-envoy-upstream-service-time: 6
<
Hello from behind Envoy (service 1)! hostname: 3dc787578c23 resolvedhostname: 192.168.160.6
$ curl -v localhost:8080/service/1
* Trying 192.168.99.100...
* Connected to 192.168.99.100 (192.168.99.100) port 8080 (#0)
> GET /service/1 HTTP/1.1
> Host: 192.168.99.100:8080
> User-Agent: curl/7.54.0
> Accept: */*
>
< HTTP/1.1 200 OK
< content-type: text/html; charset=utf-8
< content-length: 89
< x-envoy-upstream-service-time: 1
< server: envoy
< date: Fri, 26 Aug 2018 19:40:22 GMT
<
Hello from behind Envoy (service 1)! hostname: 3a93ece62129 resolvedhostname: 192.168.160.5
$ curl -v localhost:8080/service/1
* Trying 192.168.99.100...
* Connected to 192.168.99.100 (192.168.99.100) port 8080 (#0)
> GET /service/1 HTTP/1.1
> Host: 192.168.99.100:8080
> User-Agent: curl/7.43.0
> Accept: */*
>
< HTTP/1.1 200 OK
< content-type: text/html; charset=utf-8
< content-length: 89
< x-envoy-upstream-service-time: 1
< server: envoy
< date: Fri, 26 Aug 2018 19:40:24 GMT
< x-envoy-protocol-version: HTTP/1.1
<
Hello from behind Envoy (service 1)! hostname: 36418bc3c824 resolvedhostname: 192.168.160.4
Step 4: Enter containers and curl services
******************************************
In addition of using ``curl`` from your host machine, you can also enter the
containers themselves and ``curl`` from inside them. To enter a container you
can use ``docker-compose exec <container_name> /bin/bash``. For example we can
enter the ``front-envoy`` container, and ``curl`` for services locally:
.. code-block:: console
$ docker-compose exec front-envoy /bin/bash
root@81288499f9d7:/# curl localhost:8080/service/1
Hello from behind Envoy (service 1)! hostname: 85ac151715c6 resolvedhostname: 172.19.0.3
root@81288499f9d7:/# curl localhost:8080/service/1
Hello from behind Envoy (service 1)! hostname: 20da22cfc955 resolvedhostname: 172.19.0.5
root@81288499f9d7:/# curl localhost:8080/service/1
Hello from behind Envoy (service 1)! hostname: f26027f1ce28 resolvedhostname: 172.19.0.6
root@81288499f9d7:/# curl localhost:8080/service/2
Hello from behind Envoy (service 2)! hostname: 92f4a3737bbc resolvedhostname: 172.19.0.2
Step 5: Enter container and curl admin
**************************************
When Envoy runs it also attaches an ``admin`` to your desired port.
In the example configs the admin is bound to port ``8001``.
We can ``curl`` it to gain useful information:
- :ref:`/server_info <operations_admin_interface_server_info>` provides information about the Envoy version you are running.
- :ref:`/stats <operations_admin_interface_stats>` provides statistics about the Envoy server.
In the example we can enter the ``front-envoy`` container to query admin:
.. code-block:: console
$ docker-compose exec front-envoy /bin/bash
root@e654c2c83277:/# curl localhost:8001/server_info
.. code-block:: json
{
"version": "093e2ffe046313242144d0431f1bb5cf18d82544/1.15.0-dev/Clean/RELEASE/BoringSSL",
"state": "LIVE",
"hot_restart_version": "11.104",
"command_line_options": {
"base_id": "0",
"use_dynamic_base_id": false,
"base_id_path": "",
"concurrency": 8,
"config_path": "/etc/front-envoy.yaml",
"config_yaml": "",
"allow_unknown_static_fields": false,
"reject_unknown_dynamic_fields": false,
"ignore_unknown_dynamic_fields": false,
"admin_address_path": "",
"local_address_ip_version": "v4",
"log_level": "info",
"component_log_level": "",
"log_format": "[%Y-%m-%d %T.%e][%t][%l][%n] [%g:%#] %v",
"log_format_escaped": false,
"log_path": "",
"service_cluster": "front-proxy",
"service_node": "",
"service_zone": "",
"drain_strategy": "Gradual",
"mode": "Serve",
"disable_hot_restart": false,
"enable_mutex_tracing": false,
"restart_epoch": 0,
"cpuset_threads": false,
"disabled_extensions": [],
"bootstrap_version": 0,
"hidden_envoy_deprecated_max_stats": "0",
"hidden_envoy_deprecated_max_obj_name_len": "0",
"file_flush_interval": "10s",
"drain_time": "600s",
"parent_shutdown_time": "900s"
},
"uptime_current_epoch": "188s",
"uptime_all_epochs": "188s"
}
.. code-block:: console
root@e654c2c83277:/# curl localhost:8001/stats
cluster.service1.external.upstream_rq_200: 7
...
cluster.service1.membership_change: 2
cluster.service1.membership_total: 3
...
cluster.service1.upstream_cx_http2_total: 3
...
cluster.service1.upstream_rq_total: 7
...
cluster.service2.external.upstream_rq_200: 2
...
cluster.service2.membership_change: 1
cluster.service2.membership_total: 1
...
cluster.service2.upstream_cx_http2_total: 1
...
cluster.service2.upstream_rq_total: 2
...
Notice that we can get the number of members of upstream clusters, number of requests fulfilled by
them, information about http ingress, and a plethora of other useful stats.
.. seealso::
:ref:`Envoy admin quick start guide <start_quick_start_admin>`
Quick start guide to the Envoy admin interface.