Lua

SSH Tunnel Thread Activity Log

Demonstrates the tunnel-log properties KeepTunnelLog, TunnelLog, and TunnelLogPath, which record the activity of the SSH tunnel and client-manager threads.

Note: The log paths are relative to the application's current working directory. Absolute paths may also be used.

Background: This is the counterpart to the accept log, covering the SSH side rather than the listener: the tunnel and client-manager threads that actually move data. As with the accept log, KeepTunnelLog enables the in-memory TunnelLog while TunnelLogPath writes a separate file. Together the two logs let you localize a problem to either the accepting side or the forwarding side.

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Lua

local chilkat = require("chilkat")

-- Demonstrates the SshTunnel tunnel-log properties KeepTunnelLog, TunnelLog, and TunnelLogPath.
--
-- These log the activity of the SSH tunnel and client-manager threads.

local tunnel = chilkat.SshTunnel.new()

-- Retain the SSH tunnel-thread activity in memory so it can be read from the TunnelLog property.
tunnel.keep_tunnel_log = true

-- Optionally also write the tunnel-thread activity to a file (separate from the in-memory log).
tunnel.tunnel_log_path = "qa_output/tunnel.log"

tunnel.dest_hostname = "db.internal.example.com"
tunnel.dest_port = 5432

local sshPort = 22
local success = tunnel:connect("ssh.example.com", sshPort)
if not success then
    print(tunnel.last_error_text)
    return
end

-- Normally you would not hard-code the password in source.  You should instead obtain it
-- from an interactive prompt, environment variable, or a secrets vault.
local password = "mySshPassword"

success = tunnel:authenticate_pw("mySshLogin", password)
if not success then
    print(tunnel.last_error_text)
    return
end

local listenPort = 1080
success = tunnel:begin_accepting(listenPort)
if not success then
    print(tunnel.last_error_text)
    return
end

-- ... clients transfer data through the tunnel ...

-- Read the accumulated in-memory tunnel log.
print(tunnel.tunnel_log)

local waitForThreadExit = true
success = tunnel:close_tunnel(waitForThreadExit)
if not success then
    print(tunnel.last_error_text)
    return
end