3e672b784d
The linker discards whole files in an archive if it doesn't need them, so saves a bit of space (and time). Also allows us to add more niche things to CCAN (e.g. runes support!) without bloating all the binaries. We also had many places which depended on $(CCAN_FILES), but that was already a dependent of $(ALL_PROGRAMS) and $(ALL_TEST_PROGRAMS). Before: ``` $ size lightningd/lightning*d text data bss dec hex filename 2247683 8696 39008 2295387 23065b lightningd/lightning_channeld 2086607 7432 38880 2132919 208bb7 lightningd/lightning_closingd 2227916 8056 39200 2275172 22b764 lightningd/lightning_connectd 3369236 119288 39240 3527764 35d454 lightningd/lightningd 2183551 8352 38880 2230783 2209ff lightningd/lightning_dualopend 2196389 8024 39136 2243549 223bdd lightningd/lightning_gossipd 2086216 7488 39264 2132968 208be8 lightningd/lightning_hsmd 2134396 8136 39424 2181956 214b44 lightningd/lightning_onchaind 2133391 8352 38880 2180623 21460f lightningd/lightning_openingd 1512168 2136 34384 1548688 17a190 lightningd/lightning_websocketd ``` After: ``` text data bss dec hex filename 2192065 8488 38912 2239465 222be9 lightningd/lightning_channeld 2030957 7224 38816 2076997 1fb145 lightningd/lightning_closingd 2179571 7968 39104 2226643 21f9d3 lightningd/lightning_connectd 3354296 119288 39208 3512792 3599d8 lightningd/lightningd 2127933 8144 38816 2174893 212fad lightningd/lightning_dualopend 2141699 7856 39072 2188627 216553 lightningd/lightning_gossipd 2024482 7288 5240 2037010 1f1512 lightningd/lightning_hsmd 2072074 7920 5400 2085394 1fd212 lightningd/lightning_onchaind 2077773 8144 38816 2124733 206bbd lightningd/lightning_openingd 1408958 1752 344 1411054 1587ee lightningd/lightning_websocketd ``` Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> |
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| bitcoin | ||
| ccan | ||
| channeld | ||
| cli | ||
| cln-grpc | ||
| cln-rpc | ||
| closingd | ||
| common | ||
| connectd | ||
| contrib | ||
| db | ||
| devtools | ||
| doc | ||
| external | ||
| gossipd | ||
| hsmd | ||
| lightningd | ||
| onchaind | ||
| openingd | ||
| plugins | ||
| tests | ||
| tools | ||
| wallet | ||
| wire | ||
| .clang-format | ||
| .dir-locals.el | ||
| .editorconfig | ||
| .gitattributes | ||
| .gitignore | ||
| .gitlab-ci.yml | ||
| .gitmodules | ||
| .msggen.json | ||
| action.yml | ||
| Cargo.toml | ||
| ccan_compat.h | ||
| CHANGELOG.md | ||
| configure | ||
| Dockerfile | ||
| LICENSE | ||
| Makefile | ||
| poetry.lock | ||
| pyproject.toml | ||
| README.md | ||
Core Lightning (CLN): A specification compliant Lightning Network implementation in C
Core Lightning (previously c-lightning) is a lightweight, highly customizable and standard compliant implementation of the Lightning Network protocol.
Project Status
This implementation has been in production use on the Bitcoin mainnet since early 2018, with the launch of the Blockstream Store.
We recommend getting started by experimenting on testnet (or regtest), but the implementation is considered stable and can be safely used on mainnet.
Any help testing the implementation, reporting bugs, or helping with outstanding issues is very welcome. Don't hesitate to reach out to us on IRC at #lightning-dev @ libera.chat, #c-lightning @ libera.chat, or on the implementation-specific mailing list c-lightning@lists.ozlabs.org, or on the Lightning Network-wide mailing list lightning-dev@lists.linuxfoundation.org, or on Discord core-lightning, or on Telegram Core Lightning.
Getting Started
Core Lightning only works on Linux and macOS, and requires a locally (or remotely) running bitcoind (version 0.16 or above) that is fully caught up with the network you're running on, and relays transactions (ie with blocksonly=0).
Pruning (prune=n option in bitcoin.conf) is partially supported, see here for more details.
Installation
There are 4 supported installation options:
- Installation from the Ubuntu PPA.
- Installation of a pre-compiled binary from the release page on GitHub.
- Using one of the provided docker images on the Docker Hub.
- Compiling the source code yourself as described in the installation documentation.
For the impatient here's the gist of it for Ubuntu:
sudo apt-get install -y software-properties-common
sudo add-apt-repository -u ppa:lightningnetwork/ppa
sudo apt-get install lightningd snapd
sudo snap install bitcoin-core
sudo ln -s /snap/bitcoin-core/current/bin/bitcoin{d,-cli} /usr/local/bin/
Starting lightningd
Regtest (local, fast-start) Option
If you want to experiment with lightningd, there's a script to set
up a bitcoind regtest test network of two local lightning nodes,
which provides a convenient start_ln helper. See the notes at the top
of the startup_regtest.sh file for details on how to use it.
. contrib/startup_regtest.sh
Note that your local nodeset will be much faster/more responsive if you've configured your node to expose the developer options, e.g.
./configure --enable-developer
Mainnet Option
To test with real bitcoin, you will need to have a local bitcoind node running:
bitcoind -daemon
Wait until bitcoind has synchronized with the network.
Make sure that you do not have walletbroadcast=0 in your ~/.bitcoin/bitcoin.conf, or you may run into trouble.
Notice that running lightningd against a pruned node may cause some issues if not managed carefully, see below for more information.
You can start lightningd with the following command:
lightningd --network=bitcoin --log-level=debug
This creates a .lightning/ subdirectory in your home directory: see man -l doc/lightningd.8 (or https://lightning.readthedocs.io/) for more runtime options.
Using The JSON-RPC Interface
Core Lightning exposes a JSON-RPC 2.0 interface over a Unix Domain socket; the lightning-cli tool can be used to access it, or there is a python client library.
You can use lightning-cli help to print a table of RPC methods; lightning-cli help <command>
will offer specific information on that command.
Useful commands:
- newaddr: get a bitcoin address to deposit funds into your lightning node.
- listfunds: see where your funds are.
- connect: connect to another lightning node.
- fundchannel: create a channel to another connected node.
- invoice: create an invoice to get paid by another node.
- pay: pay someone else's invoice.
- plugin: commands to control extensions.
Care And Feeding Of Your New Lightning Node
Once you've started for the first time, there's a script called
contrib/bootstrap-node.sh which will connect you to other nodes on
the lightning network.
There are also numerous plugins available for Core Lightning which add capabilities: in particular there's a collection at:
https://github.com/lightningd/plugins
Including helpme which guides you through setting up your first channels and customizing your node.
For a less reckless experience, you can encrypt the HD wallet seed: see HD wallet encryption.
You can also chat to other users at #c-lightning @ libera.chat; we are always happy to help you get started!
Opening A Channel
First you need to transfer some funds to lightningd so that it can
open a channel:
# Returns an address <address>
lightning-cli newaddr
lightningd will register the funds once the transaction is confirmed.
You may need to generate a p2sh-segwit address if the faucet does not support bech32:
# Return a p2sh-segwit address
lightning-cli newaddr p2sh-segwit
Confirm lightningd got funds by:
# Returns an array of on-chain funds.
lightning-cli listfunds
Once lightningd has funds, we can connect to a node and open a channel.
Let's assume the remote node is accepting connections at <ip>
(and optional <port>, if not 9735) and has the node ID <node_id>:
lightning-cli connect <node_id> <ip> [<port>]
lightning-cli fundchannel <node_id> <amount_in_satoshis>
This opens a connection and, on top of that connection, then opens a channel.
The funding transaction needs 3 confirmation in order for the channel to be usable, and 6 to be announced for others to use.
You can check the status of the channel using lightning-cli listpeers, which after 3 confirmations (1 on testnet) should say that state is CHANNELD_NORMAL; after 6 confirmations you can use lightning-cli listchannels to verify that the public field is now true.
Sending and Receiving Payments
Payments in Lightning are invoice based.
The recipient creates an invoice with the expected <amount> in
millisatoshi (or "any" for a donation), a unique <label> and a
<description> the payer will see:
lightning-cli invoice <amount> <label> <description>
This returns some internal details, and a standard invoice string called bolt11 (named after the BOLT #11 lightning spec).
The sender can feed this bolt11 string to the decodepay command to see what it is, and pay it simply using the pay command:
lightning-cli pay <bolt11>
Note that there are lower-level interfaces (and more options to these interfaces) for more sophisticated use.
Configuration File
lightningd can be configured either by passing options via the command line, or via a configuration file.
Command line options will always override the values in the configuration file.
To use a configuration file, create a file named config within your top-level lightning directory or network subdirectory
(eg. ~/.lightning/config or ~/.lightning/bitcoin/config). See man -l doc/lightningd-config.5.
Further information
Pruning
Core Lightning requires JSON-RPC access to a fully synchronized bitcoind in order to synchronize with the Bitcoin network.
Access to ZeroMQ is not required and bitcoind does not need to be run with txindex like other implementations.
The lightning daemon will poll bitcoind for new blocks that it hasn't processed yet, thus synchronizing itself with bitcoind.
If bitcoind prunes a block that Core Lightning has not processed yet, e.g., Core Lightning was not running for a prolonged period, then bitcoind will not be able to serve the missing blocks, hence Core Lightning will not be able to synchronize anymore and will be stuck.
In order to avoid this situation you should be monitoring the gap between Core Lightning's blockheight using lightning-cli getinfo and bitcoind's blockheight using bitcoin-cli getblockchaininfo.
If the two blockheights drift apart it might be necessary to intervene.
HD wallet encryption
You can encrypt the hsm_secret content (which is used to derive the HD wallet's master key) by passing the --encrypted-hsm startup argument, or by using the hsmtool (which you can find in the tool/ directory at the root of this repo) with the encrypt method. You can unencrypt an encrypted hsm_secret using the hsmtool with the decrypt method.
If you encrypt your hsm_secret, you will have to pass the --encrypted-hsm startup option to lightningd. Once your hsm_secret is encrypted, you will not be able to access your funds without your password, so please beware with your password management. Also, beware of not feeling too safe with an encrypted hsm_secret: unlike for bitcoind where the wallet encryption can restrict the usage of some RPC command, lightningd always needs to access keys from the wallet which is thus not locked (yet), even with an encrypted BIP32 master seed.
Developers
Developers wishing to contribute should start with the developer guide here.
You should also configure with --enable-developer to get additional checks and options.