Using the Envoy Docker Image¶
The following examples use the official Envoy Docker image.
These instructions are known to work for the x86_64
and arm64
architectures.
Running Envoy with docker-compose¶
If you would like to use Envoy with docker-compose you can overwrite the provided configuration file by using a volume.
version: '3'
services:
envoy:
image: envoyproxy/envoy:v1.22.6
ports:
- "10000:10000"
volumes:
- ./envoy.yaml:/etc/envoy/envoy.yaml
If you use this method, you will have to ensure that the envoy
user can read the mounted file
either by ensuring the correct permissions on the file, or making it world-readable, as described
below.
Build and run a Docker image¶
Create a simple Dockerfile to execute Envoy.
If you create a custom envoy.yaml
you can create your own Docker image with it using the following
Dockerfile recipe:
FROM envoyproxy/envoy:v1.22.6
COPY envoy.yaml /etc/envoy/envoy.yaml
RUN chmod go+r /etc/envoy/envoy.yaml
Build the Docker image using:
$ docker build -t envoy:v1 .
Assuming Envoy is configured to listen on ports 9901
and 10000
, you can now start it
with:
$ docker run -d --name envoy -p 9901:9901 -p 10000:10000 envoy:v1
Permissions for running Docker Envoy containers as a non-root user¶
By default, the Envoy Docker image will start as the root user but will switch to the envoy
user created at build time, in the Docker ENTRYPOINT
.
Alternatively, you can start the container specifying the Docker user
.
In this case the container will not attempt to drop privileges, but you will still need to ensure that the user running inside the container has any required permissions, as described below.
Changing the uid
and/or gid
of the envoy
user inside the container¶
The default uid
and gid
for the envoy
user are 101
.
The uid
and gid
of this user can be set at runtime using the ENVOY_UID
and ENVOY_GID
environment variables.
This can be done, for example, on the Docker command line:
$ docker run -d --name envoy -e ENVOY_UID=777 -e ENVOY_GID=777 envoyproxy/envoy:v1.22.6
This can be useful if you wish to restrict or provide access to unix
sockets inside the container, or
for controlling access to an Envoy socket from outside of the container.
To run the process inside the container as the root
user you can set ENVOY_UID
to 0
,
but doing so has the potential to weaken the security of your running container.
Logging permissions inside the Envoy container¶
The envoy
image sends application logs to /dev/stdout
and /dev/stderr
by default, and these
can be viewed in the container log.
If you send application, admin or access logs to a file output, the envoy
user will require the
necessary permissions to write to this file. This can be achieved by setting the ENVOY_UID
and/or
by making the file writeable by the envoy user.
For example, to mount a log folder from the host and make it writable, you can:
$ mkdir logs
$ chown 777 logs
$ docker run -d --name envoy -v $(pwd)/logs:/var/log -e ENVOY_UID=777 envoyproxy/envoy:v1.22.6
You can then configure envoy
to log to files in /var/log
Configuration and binary file permissions inside the Envoy container¶
The envoy
user also needs to have permission to access any required configuration files mounted
into the container.
Any binary files specified in the configuration should also be executable by the envoy
user.
If you are running in an environment with a strict umask
setting, you may need to provide envoy
with access by setting the ownership and/or permissions of the file.
One method of doing this without changing any file permissions is to start the container with the
host user’s uid
, for example:
$ docker run -d --name envoy -v $(pwd)/envoy.yaml:/etc/envoy/envoy.yaml -e ENVOY_UID=$(id -u) envoyproxy/envoy:v1.22.6
Listen only on ports > 1024 inside the Docker Envoy container¶
Unix-based systems restrict opening well-known
ports (ie. with a port number < 1024
) to the root
user.
If you need to listen on a well-known
port you can use Docker to do so.
For example, to create an Envoy server listening on port 8000
, with forwarding from port 80
:
$ docker run -d --name envoy -p 80:8000 envoyproxy/envoy:v1.22.6