Run Envoy

The following instructions walk through starting Envoy as a system daemon or using the Envoy Docker image.

Check your Envoy version

Once you have installed Envoy, you can check the version information as follows:

$ envoy --version

View the Envoy command line options

You can view the Envoy command line options with the --help flag:

$ envoy --help

Run Envoy with the demo configuration

The -c or --config-path flag tells Envoy the path to its initial configuration.

To start Envoy as a system daemon download the demo configuration, and start as follows:

$ envoy -c envoy-demo.yaml

Check Envoy is proxying on http://localhost:10000.

$ curl -v localhost:10000

You can exit the server with Ctrl-c.

See the admin quick start guide for more information about the Envoy admin interface.

Override the default configuration

You can provide an override configuration using --config-yaml which will merge with the main configuration.

This option can only be specified once.

Save the following snippet to envoy-override.yaml:

      port_value: 9902

Next, start the Envoy server using the override configuration:

On Linux/Mac: run:

$ envoy -c envoy-demo.yaml --config-yaml "$(cat envoy-override.yaml)"

On Windows run:

$ envoy -c envoy-demo.yaml --config-yaml "$(Get-Content -Raw envoy-override.yaml)"

The Envoy admin interface should now be available on http://localhost:9902.

$ curl -v localhost:9902


When merging yaml lists (e.g. listeners or clusters) the merged configurations are appended.

You cannot therefore use an override file to change the configurations of previously specified listeners or clusters

Validating your Envoy configuration

You can start Envoy in validate mode.

This allows you to check that Envoy is able to start with your configuration, without actually starting or restarting the service, or making any network connections.

If the configuration is valid the process will print OK and exit with a return code of 0.

For invalid configuration the process will print the errors and exit with 1.

$ envoy --mode validate -c my-envoy-config.yaml
[2020-11-08 12:36:06.543][11][info][main] [source/server/] runtime: layers:
- name: base
- name: admin
[2020-11-08 12:36:06.543][11][info][config] [source/server/] loading tracing configuration
[2020-11-08 12:36:06.543][11][info][config] [source/server/] loading 0 static secret(s)
[2020-11-08 12:36:06.543][11][info][config] [source/server/] loading 1 cluster(s)
[2020-11-08 12:36:06.546][11][info][config] [source/server/] loading 1 listener(s)
[2020-11-08 12:36:06.549][11][info][config] [source/server/] loading stats sink configuration
configuration 'my-envoy-config.yaml' OK

Envoy logging

By default Envoy system logs are sent to /dev/stderr.

This can be overridden using --log-path.

$ mkdir logs
$ envoy -c envoy-demo.yaml --log-path logs/custom.log

Access log paths can be set for the admin interface, and for configured listeners.

The demo configuration is configured with a listener that logs access to /dev/stdout:

          stat_prefix: ingress_http
          - name: envoy.access_loggers.stdout
          - name: envoy.filters.http.router
            name: local_route

The default configuration in the Envoy Docker container also logs access in this way.

Logging to /dev/stderr and /dev/stdout for system and access logs respectively can be useful when running Envoy inside a container as the streams can be separated, and logging requires no additional files or directories to be mounted.

Some Envoy filters and extensions may also have additional logging capabilities.

Envoy can be configured to log to different formats, and to different outputs in addition to files and stdout/err.

Debugging Envoy

The log level for Envoy system logs can be set using the -l or --log-level option.

The available log levels are:

  • trace

  • debug

  • info

  • warning/warn

  • error

  • critical

  • off

The default is info.

You can also set the log level for specific components using the --component-log-level option.

The following example inhibits all logging except for the upstream and connection components, which are set to debug and trace respectively.

$ envoy -c envoy-demo.yaml -l off --component-log-level upstream:debug,connection:trace


See ALL_LOGGER_IDS in logger.h for a list of components.