nix-bitcoin/modules/bitcoind.nix
Erik Arvstedt 3b842e5fe7
add nix-bitcoin-secrets.target
Remove use of nixops-specific 'keys' group and key services.
Instead:
- Add nix-bitcoin-secrets.target, which should be required by all
  units that depend on secrets. (To keep it simple, it's okay to meet
  the secrets dependency indirectly by e.g. depending on bitcoind.)

  Various secret deployment methods can use this target by
  setting up the secrets before activating the target.
  In case of nixops we just specify that nixops' keys.target comes
  before nix-bitcoin-secrets.target.

  If the target is left undefined in the case of manual secrets
  deployment, systemd will simply ignore unit dependencies on
  the target.

- Allow all users to access the secrets dir.
  The access protection for the individual secret files is unchanged.
  This allows us to drop the unit dependency on the nixops 'keys' group.
2020-01-09 10:43:29 +01:00

306 lines
10 KiB
Nix

{ config, pkgs, lib, ... }:
with lib;
let
nix-bitcoin-services = pkgs.callPackage ./nix-bitcoin-services.nix { };
cfg = config.services.bitcoind;
pidFile = "${cfg.dataDir}/bitcoind.pid";
configFile = pkgs.writeText "bitcoin.conf" ''
${optionalString cfg.testnet "testnet=1"}
${optionalString (cfg.dbCache != null) "dbcache=${toString cfg.dbCache}"}
${optionalString (cfg.prune != null) "prune=${toString cfg.prune}"}
${optionalString (cfg.sysperms != null) "sysperms=${if cfg.sysperms then "1" else "0"}"}
${optionalString (cfg.disablewallet != null) "disablewallet=${if cfg.disablewallet then "1" else "0"}"}
# Connection options
${optionalString (cfg.port != null) "port=${toString cfg.port}"}
${optionalString (cfg.proxy != null) "proxy=${cfg.proxy}"}
listen=${if cfg.listen then "1" else "0"}
# RPC server options
${optionalString (cfg.rpc.port != null) "rpcport=${toString cfg.rpc.port}"}
${concatMapStringsSep "\n"
(rpcUser: "rpcauth=${rpcUser.name}:${rpcUser.passwordHMAC}")
(attrValues cfg.rpc.users)
}
${optionalString (cfg.rpcuser != null) "rpcuser=${cfg.rpcuser}"}
${optionalString (cfg.rpcpassword != null) "rpcpassword=${cfg.rpcpassword}"}
# ZMQ options
${optionalString (cfg.zmqpubrawblock != null) "zmqpubrawblock=${cfg.zmqpubrawblock}"}
${optionalString (cfg.zmqpubrawtx != null) "zmqpubrawtx=${cfg.zmqpubrawtx}"}
# Extra config options (from bitcoind nixos service)
${cfg.extraConfig}
'';
cmdlineOptions = concatMapStringsSep " " (arg: "'${arg}'") [
"-datadir=${cfg.dataDir}"
"-pid=${pidFile}"
];
hexStr = types.strMatching "[0-9a-f]+";
rpcUserOpts = { name, ... }: {
options = {
name = mkOption {
type = types.str;
example = "alice";
description = ''
Username for JSON-RPC connections.
'';
};
passwordHMAC = mkOption {
type = with types; uniq (strMatching "[0-9a-f]+\\$[0-9a-f]{64}");
example = "f7efda5c189b999524f151318c0c86$d5b51b3beffbc02b724e5d095828e0bc8b2456e9ac8757ae3211a5d9b16a22ae";
description = ''
Password HMAC-SHA-256 for JSON-RPC connections. Must be a string of the
format <SALT-HEX>$<HMAC-HEX>.
'';
};
};
config = {
name = mkDefault name;
};
};
in {
options = {
services.bitcoind = {
enable = mkEnableOption "Bitcoin daemon";
package = mkOption {
type = types.package;
default = pkgs.blockchains.bitcoind;
defaultText = "pkgs.blockchains.bitcoind";
description = "The package providing bitcoin binaries.";
};
extraConfig = mkOption {
type = types.lines;
default = "";
example = ''
par=16
rpcthreads=16
logips=1
'';
description = "Additional configurations to be appended to <filename>bitcoin.conf</filename>.";
};
dataDir = mkOption {
type = types.path;
default = "/var/lib/bitcoind";
description = "The data directory for bitcoind.";
};
configFileOption = mkOption {
type = types.path;
default = configFile;
description = "The data directory for bitcoind.";
};
user = mkOption {
type = types.str;
default = "bitcoin";
description = "The user as which to run bitcoind.";
};
group = mkOption {
type = types.str;
default = cfg.user;
description = "The group as which to run bitcoind.";
};
rpc = {
port = mkOption {
type = types.nullOr types.ints.u16;
default = null;
description = "Override the default port on which to listen for JSON-RPC connections.";
};
users = mkOption {
default = {};
example = {
alice.passwordHMAC = "f7efda5c189b999524f151318c0c86$d5b51b3beffbc02b724e5d095828e0bc8b2456e9ac8757ae3211a5d9b16a22ae";
bob.passwordHMAC = "b2dd077cb54591a2f3139e69a897ac$4e71f08d48b4347cf8eff3815c0e25ae2e9a4340474079f55705f40574f4ec99";
};
type = with types; loaOf (submodule rpcUserOpts);
description = ''
RPC user information for JSON-RPC connnections.
'';
};
};
rpcuser = mkOption {
type = types.nullOr types.str;
default = null;
description = "Username for JSON-RPC connections";
};
rpcpassword = mkOption {
type = types.nullOr types.str;
default = null;
description = "Password for JSON-RPC connections";
};
testnet = mkOption {
type = types.bool;
default = false;
description = "Whether to use the test chain.";
};
port = mkOption {
type = types.nullOr types.ints.u16;
default = null;
description = "Override the default port on which to listen for connections.";
};
proxy = mkOption {
type = types.nullOr types.str;
default = null;
description = "Connect through SOCKS5 proxy";
};
listen = mkOption {
type = types.bool;
default = false;
description = ''
If enabled, the bitcoin service will listen.
'';
};
sysperms = mkOption {
type = types.nullOr types.bool;
default = null;
description = ''
Create new files with system default permissions, instead of umask 077 (only effective with disabled wallet functionality)
'';
};
disablewallet = mkOption {
type = types.nullOr types.bool;
default = null;
description = ''
Do not load the wallet and disable wallet RPC calls
'';
};
dbCache = mkOption {
type = types.nullOr (types.ints.between 4 16384);
default = null;
example = 4000;
description = "Override the default database cache size in megabytes.";
};
prune = mkOption {
type = types.nullOr (types.coercedTo
(types.enum [ "disable" "manual" ])
(x: if x == "disable" then 0 else 1)
types.ints.unsigned
);
default = null;
example = 10000;
description = ''
Reduce storage requirements by enabling pruning (deleting) of old
blocks. This allows the pruneblockchain RPC to be called to delete
specific blocks, and enables automatic pruning of old blocks if a
target size in MiB is provided. This mode is incompatible with -txindex
and -rescan. Warning: Reverting this setting requires re-downloading
the entire blockchain. ("disable" = disable pruning blocks, "manual"
= allow manual pruning via RPC, >=550 = automatically prune block files
to stay under the specified target size in MiB)
'';
};
zmqpubrawblock = mkOption {
type = types.nullOr types.str;
default = null;
example = "tcp://127.0.0.1:28332";
description = "ZMQ address for zmqpubrawblock notifications";
};
zmqpubrawtx = mkOption {
type = types.nullOr types.str;
default = null;
example = "tcp://127.0.0.1:28333";
description = "ZMQ address for zmqpubrawtx notifications";
};
cli = mkOption {
type = types.package;
readOnly = true;
default = pkgs.writeScriptBin "bitcoin-cli" ''
exec ${cfg.package}/bin/bitcoin-cli -datadir='${cfg.dataDir}' "$@"
'';
description = "Binary to connect with the bitcoind instance.";
};
enforceTor = nix-bitcoin-services.enforceTor;
};
};
config = mkIf cfg.enable {
environment.systemPackages = [ cfg.package ];
systemd.services.bitcoind = {
description = "Bitcoin daemon";
requires = [ "nix-bitcoin-secrets.target" ];
after = [ "network.target" "nix-bitcoin-secrets.target" ];
wantedBy = [ "multi-user.target" ];
preStart = ''
if ! test -e ${cfg.dataDir}; then
mkdir -m 0770 -p '${cfg.dataDir}'
fi
if ! test -e ${cfg.dataDir}/blocks; then
mkdir -m 0770 -p '${cfg.dataDir}/blocks'
fi
cp '${cfg.configFileOption}' '${cfg.dataDir}/bitcoin.conf'
chmod o-rw '${cfg.dataDir}/bitcoin.conf'
chown -R '${cfg.user}:${cfg.group}' '${cfg.dataDir}'
echo "rpcpassword=$(cat /secrets/bitcoin-rpcpassword)" >> '${cfg.dataDir}/bitcoin.conf'
chmod -R g+rX '${cfg.dataDir}/blocks'
'';
serviceConfig = {
Type = "simple";
User = "${cfg.user}";
Group = "${cfg.group}";
ExecStart = "${cfg.package}/bin/bitcoind ${cmdlineOptions}";
PIDFile = "${pidFile}";
Restart = "on-failure";
# Hardening measures
PrivateTmp = "true";
ProtectSystem = "full";
NoNewPrivileges = "true";
PrivateDevices = "true";
MemoryDenyWriteExecute = "true";
# Permission for preStart
PermissionsStartOnly = "true";
} // nix-bitcoin-services.defaultHardening
// (if cfg.enforceTor
then nix-bitcoin-services.allowTor
else nix-bitcoin-services.allowAnyIP)
// optionalAttrs (cfg.zmqpubrawblock != null || cfg.zmqpubrawtx != null) nix-bitcoin-services.allowAnyProtocol;
};
# Use this to update the banlist:
# wget https://people.xiph.org/~greg/banlist.cli.txt
systemd.services.bitcoind-import-banlist = {
description = "Bitcoin daemon banlist importer";
wantedBy = [ "bitcoind.service" ];
bindsTo = [ "bitcoind.service" ];
after = [ "bitcoind.service" ];
script = ''
cd ${cfg.cli}/bin
# Poll until bitcoind accepts commands. This can take a long time.
while ! ./bitcoin-cli getnetworkinfo &> /dev/null; do
sleep 1
done
echo "Importing node banlist..."
cat ${./banlist.cli.txt} | while read line; do
if ! err=$(eval "$line" 2>&1) && [[ $err != *already\ banned* ]]; then
# unexpected error
echo "$err"
exit 1
fi
done
'';
serviceConfig = {
User = "${cfg.user}";
Group = "${cfg.group}";
} // nix-bitcoin-services.defaultHardening
// nix-bitcoin-services.allowTor;
};
users.users.${cfg.user} = {
group = cfg.group;
description = "Bitcoin daemon user";
home = cfg.dataDir;
};
users.groups.${cfg.group} = {};
users.groups.bitcoinrpc = {};
};
}