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Zero Fundamentals: Secure TCP and SSH Connections

Now that you’ve built several routes, you'll learn how to proxy TCP and SSH connections with Pomerium Zero.

Before You Start

Make sure you’ve completed the following tutorials:

Each tutorial builds on the same configuration files. In this guide, you'll proxy TCP connections to a Redis database and a remote OpenSSH server.

Background​

When replacing a traditional VPN, there are often non-HTTP based applications you still need to reach. Pomerium can provide the same type of protection to these services with Pomerium CLI, a client-side application to proxy TCP connections.

In this guide, you'll proxy TCP connections to a Redis database and an OpenSSH server.

Pomerium’s CLI client comes with a tcp command that you can use to secure these connections.

Prerequisites​

To complete this guide, you need:

  • Pomerium CLI to proxy TCP connections between end-users and services behind Pomerium
note

This guide assumes you've installed the Pomerium CLI client to your system.

Test Pomerium CLI installation​

Test the installation:

$ pomerium-cli
Usage:
  pomerium-cli [command]

Available Commands:
  cache       commands for working with the cache
  completion  Generate the autocompletion script for the specified shell
  help        Help about any command
  k8s         commands for the kubernetes credential plugin
  tcp         creates a TCP tunnel through Pomerium
  version     version

Flags:
  -h, --help      help for pomerium-cli
  -v, --version   version for pomerium-cli

Use "pomerium-cli [command] --help" for more information about a command.

Add Redis and OpenSSH services​

Add the Redis and OpenSSH server configurations to your Docker Compose file:

redis:
  image: redis:latest
  networks:
    main: {}
  expose:
    - 6379

myssh:
  image: linuxserver/openssh-server:latest
  networks:
    main: {}
  expose:
    - 2222
  environment:
    PASSWORD_ACCESS: 'true'
    USER_PASSWORD: supersecret
    USER_NAME: user

Add routes in Pomerium Zero​

Create a Redis route:

  1. Create a new route for your Redis database

  2. In From, select tcp+https:// in the protocol dropdown menu

  3. Enter your external route and append :6379 to it

    1. For example, redis.super-hero-7645.pomerium.app:6379

  4. In To, enter tcp://redis:6379

  5. In Policies, select Any Authenticated User

    Building the Redis route in the Zero Console

Create an OpenSSH route:

  1. Create a new route for the OpenSSH server

  2. In From, select tcp+https:// in the protocol dropdown menu

  3. Enter your external route and append :22 to it

    1. For example, myssh.super-hero-7645.pomerium.app:22

  4. In To, enter tcp://myssh:2222

    Building the OpenSSH route in the Zero Console

Save your changes and apply them.

Connect to Redis​

In a terminal, run the following command:

$ pomerium-cli tcp redis.<CLUSTER_SUBDOMAIN>.pomerium.app:6379 --listen localhost:6379

In a separate terminal window, run the redis-cli info command. If set up correctly, this action will prompt Pomerium to authenticate you in your browser, which will establish a TCP connection.

You should see a similar output in your terminal:

$  redis-cli info
# Server
redis_version:7.0.5
redis_git_sha1:00000000
redis_git_dirty:0
redis_build_id:d9291579292e26e3
redis_mode:standalone
os:Linux 6.3.13-linuxkit aarch64
arch_bits:64
monotonic_clock:POSIX clock_gettime
multiplexing_api:epoll
atomicvar_api:c11-builtin
gcc_version:10.2.1
process_id:1
process_supervised:no
run_id:bc1b8bcd39f1e51d615f5739158e6ae964f7e724
tcp_port:6379
server_time_usec:1713989553900448
uptime_in_seconds:64
uptime_in_days:0
hz:10
configured_hz:10
lru_clock:2713521
executable:/data/redis-server
config_file:
io_threads_active:0

We truncated the Redis response above for the sake of brevity, but it demonstrates that you successfully proxied a TCP connection to the Redis service.

Connect to SSH server​

In a terminal, run the following command:

$ pomerium-cli tcp myssh.<CLUSTER_SUBDOMAIN>.pomerium.app:22 --listen :2222

In a separate terminal window, run:

ssh user@localhost -p 2222

If set up correctly, Pomerium will open your browser to authenticate you. This will establish a TCP connection.

The SSH server will request a password, which you can find in the Docker Compose file:

  • USER_PASSWORD: supersecret
  • USER_NAME: user

After authenticating, you should see a greeting from OpenSSH, like:

$ user@myssh.<CLUSTER_SUBDOMAIN>.pomerium.app's password:
Welcome to OpenSSH Server

f157ed9f7a38:~$

Awesome! You successfully configured two services that take advantage of Pomerium's TCP capabilities to proxy requests.

Next Steps:​