Add docs for running litd in regtest in a Polar environment

[otech47]

Seems like it may be possible (#359 (comment)) currently to run litd on regtest (with any risks?) but at least for development purposes it would be great if the README or some other doc detailed how to get this running

I tried to get it working with Polar and blocked by some issue with the macaroon service. Not 100% sure if this can be solved from litd or maybe something specific to Polar... leaving this here in case it is helpful or if anyone can solve it

Getting error
error starting macaroon service: unable to unlock macaroon DB: invalid password

with specs:

OSX 12.6 (Apple M1 ARM)
Polar 1.4.0
Docker 4.13.0
LND (tried with custom LND , and v15.2)
LitD (v0.8.2-alpha commit)

[huumn]

I've managed to get it running with this config (from a working copy of our compose file):

    command:
      - 'litd'
      - '--httpslisten=0.0.0.0:8444'
      - '--insecure-httplisten=0.0.0.0:8443'
      - '--uipassword=password'
      - '--lnd-mode=remote'
      - '--network=regtest'
      - '--remote.lit-debuglevel=debug'
      - '--remote.lnd.rpcserver=stacker_lnd:10009'
      - '--remote.lnd.macaroonpath=/lnd/data/chain/bitcoin/regtest/admin.macaroon'
      - '--remote.lnd.tlscertpath=/lnd/tls.cert'
      - '--autopilot.disable'
      - '--pool.auctionserver=test.pool.lightning.finance:12010'
      - '--loop.server.host=test.swap.lightning.today:11010'

We run a regtest network without polar, but I suspect something like this should work in polar. The subserver part is the ugliest bit.

The config options are documented in code well:

lightning-terminal/config.go

Lines 149 to 227 in 080c934

	type Config struct {
	HTTPSListen string `long:"httpslisten" description:"The host:port to listen for incoming HTTP/2 connections on for the web UI only."`
	HTTPListen string `long:"insecure-httplisten" description:"The host:port to listen on with TLS disabled. This is dangerous to enable as credentials will be submitted without encryption. Should only be used in combination with Tor hidden services or other external encryption."`
	EnableREST bool `long:"enablerest" description:"Also allow REST requests to be made to the main HTTP(s) port(s) configured above."`
	RestCORS []string `long:"restcors" description:"Add an ip:port/hostname to allow cross origin access from. To allow all origins, set as \"*\"."`
	UIPassword string `long:"uipassword" description:"The password that must be entered when using the UI. Use a strong password to protect your node from unauthorized access through the web UI."`
	UIPasswordFile string `long:"uipassword_file" description:"Same as uipassword but instead of passing in the value directly, read the password from the specified file."`
	UIPasswordEnv string `long:"uipassword_env" description:"Same as uipassword but instead of passing in the value directly, read the password from the specified environment variable."`
	DisableUI bool `long:"disableui" description:"If set to true, no web UI will be served and so the uipassword will also not need to be set."`
	LetsEncrypt bool `long:"letsencrypt" description:"Use Let's Encrypt to create a TLS certificate for the UI instead of using lnd's TLS certificate. Port 80 must be free to listen on and must be reachable from the internet for this to work."`
	LetsEncryptHost string `long:"letsencrypthost" description:"The host name to create a Let's Encrypt certificate for."`
	LetsEncryptDir string `long:"letsencryptdir" description:"The directory where the Let's Encrypt library will store its key and certificate."`
	LetsEncryptListen string `long:"letsencryptlisten" description:"The IP:port on which LiT will listen for Let's Encrypt challenges. Let's Encrypt will always try to contact on port 80. Often non-root processes are not allowed to bind to ports lower than 1024. This configuration option allows a different port to be used, but must be used in combination with port forwarding from port 80. This configuration can also be used to specify another IP address to listen on, for example an IPv6 address."`
	TLSCertPath string `long:"tlscertpath" description:"Path to write the self signed TLS certificate for LiT's RPC and REST proxy service (if Let's Encrypt is not used). This only applies to the HTTPSListen port."`
	TLSKeyPath string `long:"tlskeypath" description:"Path to write the self signed TLS private key for LiT's RPC and REST proxy service (if Let's Encrypt is not used). This only applies to the HTTPSListen port."`
	LitDir string `long:"lit-dir" description:"The main directory where LiT looks for its configuration file. If LiT is running in 'remote' lnd mode, this is also the directory where the TLS certificates and log files are stored by default."`
	ConfigFile string `long:"configfile" description:"Path to LiT's configuration file."`
	MacaroonPath string `long:"macaroonpath" description:"Path to write the macaroon for litd's RPC and REST services if it doesn't exist."`
	FirstLNCConnDeadline time.Duration `long:"firstlncconndeadline" description:"The duration after a new LNC session will be revoked if no connection is made with it. This only applies for the first connection which is made using the pairing phrase. "`
	// Network is the Bitcoin network we're running on. This will be parsed
	// before the configuration is loaded and will set the correct flag on
	// `lnd.bitcoin.mainnet|testnet|regtest` and also for the other daemons.
	// That way only one global network flag is needed.
	Network string `long:"network" description:"The network the UI and all its components run on" choice:"regtest" choice:"testnet" choice:"mainnet" choice:"simnet"`
	Remote *subservers.RemoteConfig `group:"Remote mode options (use when lnd-mode=remote)" namespace:"remote"`
	// LndMode is the selected mode to run lnd in. The supported modes are
	// 'integrated' and 'remote'. We only use a string instead of a bool
	// here (and for all the other daemons) to make the CLI more user
	// friendly. Because then we can reference the explicit modes in the
	// help descriptions of the section headers. We'll parse the mode into
	// a bool for internal use for better code readability.
	LndMode string `long:"lnd-mode" description:"The mode to run lnd in, either 'remote' (default) or 'integrated'. 'integrated' means lnd is started alongside the UI and everything is stored in lnd's main data directory, configure everything by using the --lnd.* flags. 'remote' means the UI connects to an existing lnd node and acts as a proxy for gRPC calls to it. In the remote node LiT creates its own directory for log and configuration files, configure everything using the --remote.* flags." choice:"integrated" choice:"remote"`
	Lnd *lnd.Config `group:"Integrated lnd (use when lnd-mode=integrated)" namespace:"lnd"`
	FaradayMode string `long:"faraday-mode" description:"The mode to run faraday in, either 'integrated' (default), 'remote' or 'disable'. 'integrated' means faraday is started alongside the UI and everything is stored in faraday's main data directory, configure everything by using the --faraday.* flags. 'remote' means the UI connects to an existing faraday node and acts as a proxy for gRPC calls to it. 'disable' means that LiT is started without faraday." choice:"integrated" choice:"remote" choice:"disable"`
	Faraday *faraday.Config `group:"Integrated faraday options (use when faraday-mode=integrated)" namespace:"faraday"`
	LoopMode string `long:"loop-mode" description:"The mode to run loop in, either 'integrated' (default), 'remote' or 'disable'. 'integrated' means loopd is started alongside the UI and everything is stored in loop's main data directory, configure everything by using the --loop.* flags. 'remote' means the UI connects to an existing loopd node and acts as a proxy for gRPC calls to it. 'disable' means that LiT is started without loop." choice:"integrated" choice:"remote" choice:"disable"`
	Loop *loopd.Config `group:"Integrated loop options (use when loop-mode=integrated)" namespace:"loop"`
	PoolMode string `long:"pool-mode" description:"The mode to run pool in, either 'integrated' (default), 'remote' or 'disable'. 'integrated' means poold is started alongside the UI and everything is stored in pool's main data directory, configure everything by using the --pool.* flags. 'remote' means the UI connects to an existing poold node and acts as a proxy for gRPC calls to it. 'disable' means that LiT is started without pool." choice:"integrated" choice:"remote" choice:"disable"`
	Pool *pool.Config `group:"Integrated pool options (use when pool-mode=integrated)" namespace:"pool"`
	TaprootAssetsMode string `long:"taproot-assets-mode" description:"The mode to run taproot assets in, either 'integrated' (default), 'remote' or 'disable'. 'integrated' means tapd is started alongside the UI and everything is stored in tap's main data directory, configure everything by using the --taproot-assets.* flags. 'remote' means the UI connects to an existing tapd node and acts as a proxy for gRPC calls to it. 'disable' means that LiT is started without tapd" choice:"integrated" choice:"remote" choice:"disable"`
	TaprootAssets *tapcfg.Config `group:"Integrated taproot assets options (use when taproot-assets=integrated)" namespace:"taproot-assets"`
	RPCMiddleware *mid.Config `group:"RPC middleware options" namespace:"rpcmiddleware"`
	Autopilot *autopilotserver.Config `group:"Autopilot server options" namespace:"autopilot"`
	Firewall *firewall.Config `group:"Firewall options" namespace:"firewall"`
	Accounts *accounts.Config `group:"Accounts options" namespace:"accounts"`
	// faradayRpcConfig is a subset of faraday's full configuration that is
	// passed into faraday's RPC server.
	faradayRpcConfig *frdrpcserver.Config
	// lndRemote is a convenience bool variable that is parsed from the
	// LndMode string variable on startup.
	lndRemote bool
	faradayRemote bool
	loopRemote bool
	poolRemote bool
	tapRemote bool
	// lndAdminMacaroon is the admin macaroon that is given to us by lnd
	// over an in-memory connection on startup. This is only set in
	// integrated lnd mode.
	lndAdminMacaroon []byte
	}

[jamaljsr]

The latest release of Polar officially added support for running litd nodes. It should be pretty straight forward now, without needing to add docs here.