Running lightwalletd with zebra
Zebra's RPC methods can support a lightwalletd service backed by zebrad. We
recommend using
zcash/lightwalletd because we
use it in testing. Other lightwalletd
forks have limited support, see the
Sync lightwalletd section for more info.
[!NOTE] You can also use
docker
to run lightwalletd with zebra. Please see our docker documentation for more information.
Contents:
Configure zebra for lightwalletd
We need a zebra configuration file. First, we create a file with the default settings:
zebrad generate -o ~/.config/zebrad.toml
The above command places the generated zebrad.toml
config file in the default preferences directory of Linux. For other OSes default locations see here.
Tweak the following option in order to prepare for lightwalletd setup.
JSON-RPC
We need to configure Zebra to behave as an RPC endpoint. The standard RPC port for Zebra is:
8232
for Mainnet, and18232
for Testnet.
For example, to use Zebra as a lightwalletd
backend on Mainnet, give it this
~/.config/zebrad.toml
:
[rpc]
# listen for RPC queries on localhost
listen_addr = '127.0.0.1:8232'
# automatically use multiple CPU threads
parallel_cpu_threads = 0
WARNING: This config allows multiple Zebra instances to share the same RPC port. See the RPC config documentation for details.
Sync Zebra
With the configuration in place you can start synchronizing Zebra with the Zcash blockchain. This may take a while depending on your hardware.
zebrad start
Zebra will display information about sync process:
...
zebrad::commands::start: estimated progress to chain tip sync_percent=10.783 %
...
Until eventually it will get there:
...
zebrad::commands::start: finished initial sync to chain tip, using gossiped blocks sync_percent=100.000 %
...
You can interrupt the process at any time with ctrl-c
and Zebra will resume the next time at around the block you were downloading when stopping the process.
When deploying for production infrastructure, the above command can be run as a service or daemon.
For implementing zebra as a service please see here.
Download and build lightwalletd
While you synchronize Zebra you can install lightwalletd.
Before installing, you need to have go
in place. Please visit the go install page with download and installation instructions.
With go installed and in your path, download and install lightwalletd:
git clone https://github.com/zcash/lightwalletd
cd lightwalletd
make
make install
If everything went good you should have a lightwalletd
binary in ~/go/bin/
.
Sync lightwalletd
Please make sure you have zebrad running (with RPC endpoint and up to date blockchain) to synchronize lightwalletd.
-
lightwalletd
requires azcash.conf
file, however this file can be empty if you are using the default Zebra rpc endpoint (127.0.0.1:8232
) and thezcash/lightwalletd
fork.- Some
lightwalletd
forks also require arpcuser
andrpcpassword
, but Zebra ignores them if it receives them fromlightwalletd
- When using a non-default port, use
rpcport=28232
andrpcbind=127.0.0.1
- When using testnet, use
testnet=1
- Some
-
For production setups
lightwalletd
requires acert.pem
. For more information on how to do this please see here. -
lightwalletd
can run without the certificate (with the--no-tls-very-insecure
flag) however this is not recommended for production environments.
With the cert in ./
and an empty zcash.conf
we can start the sync with:
lightwalletd --zcash-conf-path ~/.config/zcash.conf --data-dir ~/.cache/lightwalletd --log-file /dev/stdout
By default lightwalletd service will listen on 127.0.0.1:9067
Lightwalletd will do its own synchronization, while it is doing you will see messages as:
...
{"app":"lightwalletd","level":"info","msg":"Ingestor adding block to cache: 748000","time":"2022-05-28T19:25:49-03:00"}
{"app":"lightwalletd","level":"info","msg":"Ingestor adding block to cache: 749540","time":"2022-05-28T19:25:53-03:00"}
{"app":"lightwalletd","level":"info","msg":"Ingestor adding block to cache: 751074","time":"2022-05-28T19:25:57-03:00"}
...
Wait until lightwalletd is in sync before connecting any wallet into it. You will know when it is in sync as those messages will not be displayed anymore.
Run tests
The Zebra team created tests for the interaction of zebrad
and lightwalletd
.
To run all the Zebra lightwalletd
tests:
- install
lightwalletd
- install
protoc
- build Zebra with
--features=lightwalletd-grpc-tests
Please refer to acceptance tests documentation in the Lightwalletd tests
section.
Connect a wallet to lightwalletd
The final goal is to connect wallets to the lightwalletd service backed by Zebra.
For demo purposes we used zecwallet-cli with the adityapk00/lightwalletd fork. We didn't test zecwallet-cli with zcash/lightwalletd yet.
Make sure both zebrad
and lightwalletd
are running and listening.
Download and build the cli-wallet
cargo install --locked --git https://github.com/adityapk00/zecwallet-light-cli
zecwallet-cli binary will be at ~/.cargo/bin/zecwallet-cli
.
Run the wallet
$ zecwallet-cli --server 127.0.0.1:9067
Lightclient connecting to http://127.0.0.1:9067/
{
"result": "success",
"latest_block": 1683911,
"total_blocks_synced": 49476
}
Ready!
(main) Block:1683911 (type 'help') >>