USP Client

USP Client is an auxiliary component used to support reverse SSH tunneling in environments where the USP Server cannot reach internal targets directly due to firewall restrictions. It establishes and maintains a secure tunnel with a USP Server, enabling secure proxying of traffic to the internal network.

Configuration Overview

The USP Client requires a minimal set of configuration parameters to establish and maintain secure tunnels. These values must be explicitly defined during installation, as they do not have default values.

• HCL Configuration File: Located at /opt/udmg/etc/usp-client.hcl. This file defines the structured configuration using HCL (HashiCorp Configuration Language), where fields are written using dot notation to express the hierarchy of nested blocks.
• Environment Variable File: Environment variables are loaded from /opt/udmg/etc/usp-client.env via the systemd unit.

info

Any configuration value defined via an environment variable will override the corresponding value in the HCL file.

Configuration File

You can specify the path to the configuration file using one of the following options (in order of precedence):

1. Environment Variable: USP_CLIENT_CONFIG
2. Command Line Flag: -c or --config
3. Default File: usp-client.hcl (lowest precedence)

Commands Usage

To view the available commands and options, run:

usp-client -h

To run a command, run:

usp-client [command]

Available Commands

Command	Description
usp-client [command] --help	Get more information about a command.
completion	Generate the autocompletion script.
help	Display help about any command.
start	Start the USP Client and initiate the tunnel connection.

Available Flags

-h, --help      help for usp-client
-v, --version   version for usp-client

Start USP Client

To start the USP Client, use:

usp-client start [flags] 

Flags:

• -c, --config string: Path to the configuration file (default: usp-client.hcl)
• -h, --help: Displays help information for the start command