Michal Čihař - Blog Archives for Debian

Running Bitcoin node and ElectrumX server

I've been tempted to run own ElectrumX server for quite some. First attempt was to run this on Turris Omnia router, however that turned out to be impossible due to memory requirements both Bitcoind and ElectrumX have.

This time I've dedicated host for this and it runs fine:

Electrum connecting to btc.cihar.com

The server runs Debian sid (probably it would be doable on stretch as well, but I didn't try much) and the setup was pretty simple.

First we need to install some things - Bitcoin daemon and ElectrumX dependencies:

# Bitcoin daemon, not available in stretch
apt install bitcoind

# We will checkout ElectrumX from git
apt install git

# ElectrumX deps
apt install python3-aiohttp

# Build environment for ElectrumX deps
apt install build-essentials python3-pip libleveldb-dev

# ElectrumX deps not packaged in Debian
pip3 install plyvel pylru

# Download ElectrumX sources
su - electrumx -c 'git clone https://github.com/kyuupichan/electrumx.git'

Create users which will run the services:

adduser bitcoind
adduser electrumx

Now it's time to prepare configuration for the services. For Bitcoin it's quite simple - we need to configure RPC interface and enable transaction index in /home/bitcoind/.bitcoin/bitcoin.conf:

txindex=1
listen=1
rpcuser=bitcoin
rpcpassword=somerandompassword

The ElectrumX configuration is quite simple as well and it's pretty well documented. I've decided to place it in /etc/electrumx.conf:

COIN=BitcoinSegwit
DB_DIRECTORY=/home/electrumx/.electrumx
DAEMON_URL=http://bitcoin:somerandompassword@localhost:8332/
TCP_PORT=50001
SSL_PORT=50002
HOST=::

DONATION_ADDRESS=3KPccmPtejpMczeog7dcFdqX4oTebYZ3tF

SSL_CERTFILE=/etc/letsencrypt/live/btc.cihar.com/fullchain.pem
SSL_KEYFILE=/etc/letsencrypt/live/btc.cihar.com/privkey.pem

REPORT_HOST=btc.cihar.com
BANNER_FILE=banner

I've decided to control both services using systemd, so it's matter of creating pretty simple units for that. Actually the Bitcoin one closely matches the one I've used on Turris Omnia and the ElectrumX the one they ship, but there are some minor changes.

Systemd unit for ElectrumX in /etc/systemd/system/electrumx.service:

[Unit]
Description=Electrumx
After=bitcoind.target

[Service]
EnvironmentFile=/etc/electrumx.conf
ExecStart=/home/electrumx/electrumx/electrumx_server.py
User=electrumx
LimitNOFILE=8192
TimeoutStopSec=30min

[Install]
WantedBy=multi-user.target

And finally systemd unit for Bitcoin daemon in /etc/systemd/system/bitcoind.service:

[Unit]
Description=Bitcoind
After=network.target

[Service]
ExecStart=/usr/bin/bitcoind
User=bitcoind
TimeoutStopSec=30min
Restart=on-failure
RestartSec=30

[Install]
WantedBy=multi-user.target

Now everything should be configured and it's time to start up the services:

# Enable services so that they start on boot 
systemctl enable electrumx.service bitcoind.service

# Start services
systemctl start electrumx.service bitcoind.service

Now you have few days time until Bitcoin fetches whole blockchain and ElectrumX indexes that. If you happen to have another Bitcoin node running (or was running in past), you can speedup the process by copying blocks from that system (located in ~/.bitcoin/blocks/). Only get blocks from sources you trust absolutely as it might change your view of history, see Bitcoin wiki for more information on the topic. There is also magnet link in the ElectrumX docs to download ElectrumX database to speed up this process. This should be safe to download from untrusted source.

The last think I'd like to mention is resources usage. You should have at least 4 GB of memory to run this, 8 GB is really preferred (both services consume around 4GB). On disk space, Bitcoin currently consumes 170 GB and ElectrumX 25 GB. Ideally all this should be running on the SSD disk.

You can however offload some of the files to slower storage as old blocks are rarely accessed and this can save some space on your storage. Following script will move around 50 GB of blockchain data to /mnt/btc/blocks (use only when Bitcoin daemon is not running):

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#!/bin/sh
set -e

DEST=/mnt/btc/blocks

cd ~/.bitcoin/blocks/

find . -type f \( -name 'blk00[0123]*.dat' -o -name 'rev00[0123]*dat' \) | sed 's@^\./@@' | while read name ; do
        mv $name $DEST/$name
        ln -s $DEST/$name $name
done

Anyway if you would like to use this server, configure btc.cihar.com in your Electrum client.

If you find this howto useful, you can send some Satoshis to 3KPccmPtejpMczeog7dcFdqX4oTebYZ3tF.

New projects on Hosted Weblate

Hosted Weblate provides also free hosting for free software projects. The hosting requests queue has grown too long, so it's time to process it and include new project.

This time, the newly hosted projects include:

If you want to support this effort, please donate to Weblate, especially recurring donations are welcome to make this service alive. You can do that easily on Liberapay or Bountysource.

Gammu 1.38.5

Today, Gammu 1.38.5 has been released. After long period of bugfix only releases, this comes with several new noteworthy features.

The biggest feature probably is that SMSD can now handle USSD messages as well. Those are usually used for things like checking remaining credit, but it's certainly not limited to this. This feature has been contributed thanks to funding on BountySource.

You can read more information in the release announcement.

Weblate 2.17

Weblate 2.17 has been released today. There are quite some performance improvements, improved search, improved access control settings and various other improvements.

Full list of changes:

  • Weblate by default does shallow Git clones now.
  • Improved performance when updating large translation files.
  • Added support for blocking certain emails from registration.
  • Users can now delete their own comments.
  • Added preview step to search and replace feature.
  • Client side persistence of settings in search and upload forms.
  • Extended search capabilities.
  • More fine grained per project ACL configuration.
  • Default value of BASE_DIR has been changed.
  • Added two step account removal to prevent accidental removal.
  • Project access control settings is now editable.
  • Added optional spam protection for suggestions using Akismet.

Update: The bugfix 2.17.1 is out as well, fixing testsuite errors in some setups:

  • Fixed running testsuite in some specific situations.
  • Locales updates.

If you are upgrading from older version, please follow our upgrading instructions.

You can find more information about Weblate on https://weblate.org, the code is hosted on Github. If you are curious how it looks, you can try it out on demo server. You can login there with demo account using demo password or register your own user. Weblate is also being used on https://hosted.weblate.org/ as official translating service for phpMyAdmin, OsmAnd, Turris, FreedomBox, Weblate itself and many other projects.

Should you be looking for hosting of translations for your project, I'm happy to host them for you or help with setting it up on your infrastructure.

Further development of Weblate would not be possible without people providing donations, thanks to everybody who have helped so far! The roadmap for next release is just being prepared, you can influence this by expressing support for individual issues either by comments or by providing bounty for them.

Using Trezor to store cryptocurencies

For quite some time I have some cryptocurrencies on hold. These mostly come from times it was possible to mine Bitcoin on the CPU, but I've got some small payments recently as well.

I've been using Electrum wallet so far. It worked quite well, but with increasing Bitcoin value, I was considering having some hardware wallet for that. There are few options which you can use, but I've always preferred Trezor as that device is made by guys I know. Also it's probably device with best support out of these (at least I've heard really bad stories about Ledger support).

In the end what decided is that they are also using Weblate to translate their user interface and offered me the wallet for free in exchange. This is price you can not beat :-). Anyway the setup was really smooth and I'm now fully set up. This also made me more open to accept other cryptocurrencies which are supported by Trezor, so you can now see more options on the Weblate donations page.

New projects on Hosted Weblate

Hosted Weblate provides also free hosting for free software projects. The hosting requests queue has grown too long, so it's time to process it and include new project.

This time, the newly hosted projects include:

  • Hunspell - famous spell checker
  • Eolie - a web browser for GNOME
  • SkyTube - an open-source YouTube app for Android
  • Eventum - issue tracking system

Additionally there were some notable additions to existing projects:

If you want to support this effort, please donate to Weblate, especially recurring donations are welcome to make this service alive. You can do that easily on Liberapay or Bountysource.

Better access control in Weblate

Upcoming Weblate 2.17 will bring improved access control settings. Previously this could be controlled only by server admins, but now the project visibility and access presets can be configured.

This allows you to better tweak access control for your needs. There is additional choice of making the project public, but restricting translations, what has been requested by several projects.

You can see the possible choices on the UI screenshot:

Weblate overall experience

On Hosted Weblate this feature is currently available only to commercial hosting customers. Projects hosted for free are limited to public visibility only.

stardicter 1.1

Stardicter 1.1, the set of scripts to convert some freely available dictionaries to StarDict format, has been released today. The biggest change is that it will also keep source data together with generated dictionaries. This is good for licensing reasons and will also allow to actually build these as packages within Debian.

Full list of changes:

  • Various cleanups for first stable release.
  • Fixed generating of README for dictionaries.
  • Added support for generating source tarballs.
  • Fixed installation on systems with non utf-8 locale.

As usual, you can install from pip, download source or download generated dictionaries from my website. The package should be soon available in Debian as well.

New projects on Hosted Weblate

Hosted Weblate provides also free hosting for free software projects. The hosting requests queue has grown too long, so it's time to process it and include new project.

This time, the newly hosted projects include:

If you want to support this effort, please donate to Weblate, especially recurring donations are welcome to make this service alive. You can do them on Liberapay or Bountysource.

Taking over siphashc for Python

Since some time we're using siphash algorithm to speed up looking up strings in Weblate. Even though it is used by Python internally, it's not exposed in the standard library so several third party modules appeared in the PyPI. Out of all these siphashc or rather it's Python 3 fork siphashc3 seemed to perform best, so I've started to use that.

However it turned out that none of them is in active maintenance anymore. The original version lacks Python 3 support, while the siphashc3 uses odd versioning which causes problems to some pip versions.

After trying to get fix into siphashc3 without much of success, I've spoken to original author of siphashc and he has agreed to hand over maintainership to me. So it's new home is at https://github.com/WeblateOrg/siphashc and new release is already available on PyPI.

Note: Originally we were using MD5 in Weblate, but siphash has shown to be faster and fits into 64-bits, what makes it easier to store and index in SQL databases as LONGINT.