.. _install_sandboxes_dynamic_config_fs: Dynamic configuration (filesystem) ================================== .. sidebar:: Requirements .. include:: _include/docker-env-setup-link.rst :ref:`curl ` Used to make ``HTTP`` requests. :ref:`jq ` Parse ``json`` output from the upstream echo servers. This example walks through configuring Envoy using filesystem-based dynamic configuration. It demonstrates how configuration provided to Envoy dynamically can be updated without restarting the server. Step 1: Start the proxy container ********************************* Change directory to ``examples/dynamic-config-fs`` in the Envoy repository. Build and start the containers. This should also start two upstream ``HTTP`` echo servers, ``service1`` and ``service2``. .. code-block:: console $ pwd envoy/examples/dynamic-config-fs $ docker-compose build --pull $ docker-compose up -d $ docker-compose ps Name Command State Ports ------------------------------------------------------------------------------------------------------------------------ dynamic-config-fs_proxy_1 /docker-entrypoint.sh /usr ... Up 0.0.0.0:10000->10000/tcp, 0.0.0.0:19000->19000/tcp dynamic-config-fs_service1_1 /bin/echo-server Up 8080/tcp dynamic-config-fs_service2_1 /bin/echo-server Up 8080/tcp Step 2: Check web response ************************** You should be able to make a request to port ``10000``, which will be served by ``service1``. .. code-block:: console $ curl -s http://localhost:10000 Request served by service1 HTTP/2.0 GET / Host: localhost:10000 User-Agent: curl/7.72.0 Accept: */* X-Forwarded-Proto: http X-Request-Id: 6672902d-56ca-456c-be6a-992a603cab9a X-Envoy-Expected-Rq-Timeout-Ms: 15000 Step 3: Dump Envoy's ``dynamic_active_clusters`` config ******************************************************* If you now dump the proxy’s :ref:`dynamic_active_clusters ` configuration, you should see it is configured with the ``example_proxy_cluster`` pointing to ``service1``. .. code-block:: console $ curl -s http://localhost:19000/config_dump | jq -r '.configs[1].dynamic_active_clusters' .. literalinclude:: _include/dynamic-config-fs/response-config-active-clusters.json :language: json :emphasize-lines: 10, 18-19 Step 4: Edit ``cds.yaml`` inside the container to update upstream cluster ************************************************************************* The example setup provides Envoy with two dynamic configuration files: - :download:`configs/cds.yaml <_include/dynamic-config-fs/configs/cds.yaml>` to provide a :ref:`Cluster discovery service (CDS) `. - :download:`configs/lds.yaml <_include/dynamic-config-fs/configs/lds.yaml>` to provide a :ref:`Listener discovery service (LDS) `. Edit ``cds.yaml`` inside the container and change the cluster address from ``service1`` to ``service2``: .. literalinclude:: _include/dynamic-config-fs/configs/cds.yaml :language: yaml :linenos: :lines: 6-13 :lineno-start: 6 :emphasize-lines: 8 You can do this using ``sed`` inside the container: .. code-block:: console docker-compose exec -T proxy sed -i s/service1/service2/ /var/lib/envoy/cds.yaml Step 5: Check Envoy uses updated configuration ********************************************** Checking the web response again, the request should now be handled by ``service2``: .. code-block:: console $ curl http://localhost:10000 | grep "served by" Request served by service2 Dumping the :ref:`dynamic_active_clusters `, the ``example_proxy_cluster`` should now be configured to proxy to ``service2``: .. code-block:: console $ curl -s http://localhost:19000/config_dump | jq -r '.configs[1].dynamic_active_clusters' .. literalinclude:: _include/dynamic-config-fs/response-config-active-clusters-updated.json :language: json :emphasize-lines: 10, 18-19 .. seealso:: :ref:`Dynamic configuration (filesystem) quick start guide ` Quick start guide to filesystem-based dynamic configuration of Envoy. :ref:`Envoy admin quick start guide ` Quick start guide to the Envoy admin interface. :ref:`Dynamic configuration (control plane) sandbox ` Configure Envoy dynamically with the Go Control Plane.