LLT-6855: Separation of daemon lifecycle from VPN connection state management

[tomasz-kumor]

Problem

Currently the VPN connection state is tightly coupled with the daemon lifecycle and there is not way to connect/disconnect VPN exit node without changing the NordVPN Lite daemon state.

Solution

• Separate nordvpnlite daemon lifecycle management from VPN connection state management.
  • Introduced nordvpnlite start --do-not-connect flag to allow separate launching the daemon from establishing VPN connection.
  • Introduced dedicated CLI connect/disconnect commands that allows to control the VPN connection state

Testing

1. Run daemon without establishing VPN connection

# ./nordvpnlite start --do-not-connect -c config.json

Check that daemon is running but VPN connection is not established

# ./nordvpnlite status
{
  "telio_is_running": true,
  "ip_address": null,
  "exit_node": null
}

Connect to the VPN exit node & check that VPN connection is established

# ./nordvpnlite connect
Command executed successfully
# /nordvpnlite status
{
  "telio_is_running": true,
  "ip_address": null,
  "exit_node": {
    "identifier": "2432424-234536f34f3-4235f34-323",
    "public_key": "cnwurvevke4747tb43y3v74659g45gh45vd5e",
    "hostname": "lt.nordvpn.com",
    "endpoint": "181.88.88.88:51320",
    "state": "connected"
  }
}

Disconnect from the VPN exit node

# ./nordvpnlite disconnect
Command executed successfully
# ./nordvpnlite status
{
  "telio_is_running": true,
  "ip_address": null,
  "exit_node": null
}

2. Check legacy behavior

# ./nordvpnlite stop
# ./nordvpnlite start -c config.json
...
# /nordvpnlite status
{
  "telio_is_running": true,
  "ip_address": null,
  "exit_node": {
    "identifier": "2432424-234536f34f3-4235f34-323",
    "public_key": "cnwurvevke4747tb43y3v74659g45gh45vd5e",
    "hostname": "lt.nordvpn.com",
    "endpoint": "181.88.88.88:51320",
    "state": "connected"
  }
}

☑️ Definition of Done checklist

• Commit history is clean (requirements)
• README.md is updated
• Functionality is covered by unit or integration tests

[lcruz99]

what's the reason for this downgrade?

[tomasz-kumor]

I just called

cargo update -p h2

which was suggested as a fix by deny CI job