{ config, lib, pkgs, ... }: let inherit (lib) concatStringsSep flip literalMD literalExpression optionalAttrs optionals recursiveUpdate mdDoc mkEnableOption mkPackageOption mkIf mkOption types versionAtLeast ; cfg = config.services.cassandra; atLeast3 = versionAtLeast cfg.package.version "3"; atLeast3_11 = versionAtLeast cfg.package.version "3.11"; atLeast4 = versionAtLeast cfg.package.version "4"; defaultUser = "cassandra"; cassandraConfig = flip recursiveUpdate cfg.extraConfig ( { commitlog_sync = "batch"; commitlog_sync_batch_window_in_ms = 2; start_native_transport = cfg.allowClients; cluster_name = cfg.clusterName; partitioner = "org.apache.cassandra.dht.Murmur3Partitioner"; endpoint_snitch = "SimpleSnitch"; data_file_directories = [ "${cfg.homeDir}/data" ]; commitlog_directory = "${cfg.homeDir}/commitlog"; saved_caches_directory = "${cfg.homeDir}/saved_caches"; } // optionalAttrs (cfg.seedAddresses != [ ]) { seed_provider = [ { class_name = "org.apache.cassandra.locator.SimpleSeedProvider"; parameters = [{ seeds = concatStringsSep "," cfg.seedAddresses; }]; } ]; } // optionalAttrs atLeast3 { hints_directory = "${cfg.homeDir}/hints"; } ); cassandraConfigWithAddresses = cassandraConfig // ( if cfg.listenAddress == null then { listen_interface = cfg.listenInterface; } else { listen_address = cfg.listenAddress; } ) // ( if cfg.rpcAddress == null then { rpc_interface = cfg.rpcInterface; } else { rpc_address = cfg.rpcAddress; } ); cassandraEtc = pkgs.stdenv.mkDerivation { name = "cassandra-etc"; cassandraYaml = builtins.toJSON cassandraConfigWithAddresses; cassandraEnvPkg = "${cfg.package}/conf/cassandra-env.sh"; cassandraLogbackConfig = pkgs.writeText "logback.xml" cfg.logbackConfig; passAsFile = [ "extraEnvSh" ]; inherit (cfg) extraEnvSh package; buildCommand = '' mkdir -p "$out" echo "$cassandraYaml" > "$out/cassandra.yaml" ln -s "$cassandraLogbackConfig" "$out/logback.xml" ( cat "$cassandraEnvPkg" echo "# lines from services.cassandra.extraEnvSh: " cat "$extraEnvShPath" ) > "$out/cassandra-env.sh" # Delete default JMX Port, otherwise we can't set it using env variable sed -i '/JMX_PORT="7199"/d' "$out/cassandra-env.sh" # Delete default password file sed -i '/-Dcom.sun.management.jmxremote.password.file=\/etc\/cassandra\/jmxremote.password/d' "$out/cassandra-env.sh" ${lib.optionalString atLeast4 '' cp $package/conf/jvm*.options $out/ ''} ''; }; defaultJmxRolesFile = builtins.foldl' (left: right: left + right) "" (map (role: "${role.username} ${role.password}") cfg.jmxRoles); fullJvmOptions = cfg.jvmOpts ++ optionals (cfg.jmxRoles != [ ]) [ "-Dcom.sun.management.jmxremote.authenticate=true" "-Dcom.sun.management.jmxremote.password.file=${cfg.jmxRolesFile}" ] ++ optionals cfg.remoteJmx [ "-Djava.rmi.server.hostname=${cfg.rpcAddress}" ] ++ optionals atLeast4 [ # Historically, we don't use a log dir, whereas the upstream scripts do # expect this. We override those by providing our own -Xlog:gc flag. "-Xlog:gc=warning,heap*=warning,age*=warning,safepoint=warning,promotion*=warning" ]; commonEnv = { # Sufficient for cassandra 2.x, 3.x CASSANDRA_CONF = "${cassandraEtc}"; # Required since cassandra 4 CASSANDRA_LOGBACK_CONF = "${cassandraEtc}/logback.xml"; }; in { options.services.cassandra = { enable = mkEnableOption (lib.mdDoc '' Apache Cassandra – Scalable and highly available database ''); clusterName = mkOption { type = types.str; default = "Test Cluster"; description = mdDoc '' The name of the cluster. This setting prevents nodes in one logical cluster from joining another. All nodes in a cluster must have the same value. ''; }; user = mkOption { type = types.str; default = defaultUser; description = mdDoc "Run Apache Cassandra under this user."; }; group = mkOption { type = types.str; default = defaultUser; description = mdDoc "Run Apache Cassandra under this group."; }; homeDir = mkOption { type = types.path; default = "/var/lib/cassandra"; description = mdDoc '' Home directory for Apache Cassandra. ''; }; package = mkPackageOption pkgs "cassandra" { example = "cassandra_3_11"; }; jvmOpts = mkOption { type = types.listOf types.str; default = [ ]; description = mdDoc '' Populate the `JVM_OPT` environment variable. ''; }; listenAddress = mkOption { type = types.nullOr types.str; default = "127.0.0.1"; example = null; description = mdDoc '' Address or interface to bind to and tell other Cassandra nodes to connect to. You _must_ change this if you want multiple nodes to be able to communicate! Set {option}`listenAddress` OR {option}`listenInterface`, not both. Leaving it blank leaves it up to `InetAddress.getLocalHost()`. This will always do the "Right Thing" _if_ the node is properly configured (hostname, name resolution, etc), and the Right Thing is to use the address associated with the hostname (it might not be). Setting {option}`listenAddress` to `0.0.0.0` is always wrong. ''; }; listenInterface = mkOption { type = types.nullOr types.str; default = null; example = "eth1"; description = mdDoc '' Set `listenAddress` OR `listenInterface`, not both. Interfaces must correspond to a single address, IP aliasing is not supported. ''; }; rpcAddress = mkOption { type = types.nullOr types.str; default = "127.0.0.1"; example = null; description = mdDoc '' The address or interface to bind the native transport server to. Set {option}`rpcAddress` OR {option}`rpcInterface`, not both. Leaving {option}`rpcAddress` blank has the same effect as on {option}`listenAddress` (i.e. it will be based on the configured hostname of the node). Note that unlike {option}`listenAddress`, you can specify `"0.0.0.0"`, but you must also set `extraConfig.broadcast_rpc_address` to a value other than `"0.0.0.0"`. For security reasons, you should not expose this port to the internet. Firewall it if needed. ''; }; rpcInterface = mkOption { type = types.nullOr types.str; default = null; example = "eth1"; description = mdDoc '' Set {option}`rpcAddress` OR {option}`rpcInterface`, not both. Interfaces must correspond to a single address, IP aliasing is not supported. ''; }; logbackConfig = mkOption { type = types.lines; default = '' %-5level %date{HH:mm:ss,SSS} %msg%n ''; description = mdDoc '' XML logback configuration for cassandra ''; }; seedAddresses = mkOption { type = types.listOf types.str; default = [ "127.0.0.1" ]; description = mdDoc '' The addresses of hosts designated as contact points in the cluster. A joining node contacts one of the nodes in the seeds list to learn the topology of the ring. Set to `[ "127.0.0.1" ]` for a single node cluster. ''; }; allowClients = mkOption { type = types.bool; default = true; description = mdDoc '' Enables or disables the native transport server (CQL binary protocol). This server uses the same address as the {option}`rpcAddress`, but the port it uses is not `rpc_port` but `native_transport_port`. See the official Cassandra docs for more information on these variables and set them using {option}`extraConfig`. ''; }; extraConfig = mkOption { type = types.attrs; default = { }; example = { commitlog_sync_batch_window_in_ms = 3; }; description = mdDoc '' Extra options to be merged into {file}`cassandra.yaml` as nix attribute set. ''; }; extraEnvSh = mkOption { type = types.lines; default = ""; example = literalExpression ''"CLASSPATH=$CLASSPATH:''${extraJar}"''; description = mdDoc '' Extra shell lines to be appended onto {file}`cassandra-env.sh`. ''; }; fullRepairInterval = mkOption { type = types.nullOr types.str; default = "3w"; example = null; description = mdDoc '' Set the interval how often full repairs are run, i.e. {command}`nodetool repair --full` is executed. See for more information. Set to `null` to disable full repairs. ''; }; fullRepairOptions = mkOption { type = types.listOf types.str; default = [ ]; example = [ "--partitioner-range" ]; description = mdDoc '' Options passed through to the full repair command. ''; }; incrementalRepairInterval = mkOption { type = types.nullOr types.str; default = "3d"; example = null; description = mdDoc '' Set the interval how often incremental repairs are run, i.e. {command}`nodetool repair` is executed. See for more information. Set to `null` to disable incremental repairs. ''; }; incrementalRepairOptions = mkOption { type = types.listOf types.str; default = [ ]; example = [ "--partitioner-range" ]; description = mdDoc '' Options passed through to the incremental repair command. ''; }; maxHeapSize = mkOption { type = types.nullOr types.str; default = null; example = "4G"; description = mdDoc '' Must be left blank or set together with {option}`heapNewSize`. If left blank a sensible value for the available amount of RAM and CPU cores is calculated. Override to set the amount of memory to allocate to the JVM at start-up. For production use you may wish to adjust this for your environment. `MAX_HEAP_SIZE` is the total amount of memory dedicated to the Java heap. `HEAP_NEWSIZE` refers to the size of the young generation. The main trade-off for the young generation is that the larger it is, the longer GC pause times will be. The shorter it is, the more expensive GC will be (usually). ''; }; heapNewSize = mkOption { type = types.nullOr types.str; default = null; example = "800M"; description = mdDoc '' Must be left blank or set together with {option}`heapNewSize`. If left blank a sensible value for the available amount of RAM and CPU cores is calculated. Override to set the amount of memory to allocate to the JVM at start-up. For production use you may wish to adjust this for your environment. `HEAP_NEWSIZE` refers to the size of the young generation. The main trade-off for the young generation is that the larger it is, the longer GC pause times will be. The shorter it is, the more expensive GC will be (usually). The example `HEAP_NEWSIZE` assumes a modern 8-core+ machine for decent pause times. If in doubt, and if you do not particularly want to tweak, go with 100 MB per physical CPU core. ''; }; mallocArenaMax = mkOption { type = types.nullOr types.int; default = null; example = 4; description = mdDoc '' Set this to control the amount of arenas per-thread in glibc. ''; }; remoteJmx = mkOption { type = types.bool; default = false; description = mdDoc '' Cassandra ships with JMX accessible *only* from localhost. To enable remote JMX connections set to true. Be sure to also enable authentication and/or TLS. See: ''; }; jmxPort = mkOption { type = types.int; default = 7199; description = mdDoc '' Specifies the default port over which Cassandra will be available for JMX connections. For security reasons, you should not expose this port to the internet. Firewall it if needed. ''; }; jmxRoles = mkOption { default = [ ]; description = mdDoc '' Roles that are allowed to access the JMX (e.g. {command}`nodetool`) BEWARE: The passwords will be stored world readable in the nix store. It's recommended to use your own protected file using {option}`jmxRolesFile` Doesn't work in versions older than 3.11 because they don't like that it's world readable. ''; type = types.listOf (types.submodule { options = { username = mkOption { type = types.str; description = lib.mdDoc "Username for JMX"; }; password = mkOption { type = types.str; description = lib.mdDoc "Password for JMX"; }; }; }); }; jmxRolesFile = mkOption { type = types.nullOr types.path; default = if atLeast3_11 then pkgs.writeText "jmx-roles-file" defaultJmxRolesFile else null; defaultText = literalMD ''generated configuration file if version is at least 3.11, otherwise `null`''; example = "/var/lib/cassandra/jmx.password"; description = lib.mdDoc '' Specify your own jmx roles file. Make sure the permissions forbid "others" from reading the file if you're using Cassandra below version 3.11. ''; }; }; config = mkIf cfg.enable { assertions = [ { assertion = (cfg.listenAddress == null) != (cfg.listenInterface == null); message = "You have to set either listenAddress or listenInterface"; } { assertion = (cfg.rpcAddress == null) != (cfg.rpcInterface == null); message = "You have to set either rpcAddress or rpcInterface"; } { assertion = (cfg.maxHeapSize == null) == (cfg.heapNewSize == null); message = "If you set either of maxHeapSize or heapNewSize you have to set both"; } { assertion = cfg.remoteJmx -> cfg.jmxRolesFile != null; message = '' If you want JMX available remotely you need to set a password using jmxRoles or jmxRolesFile if using Cassandra older than v3.11. ''; } ]; users = mkIf (cfg.user == defaultUser) { users.${defaultUser} = { group = cfg.group; home = cfg.homeDir; createHome = true; uid = config.ids.uids.cassandra; description = "Cassandra service user"; }; groups.${defaultUser}.gid = config.ids.gids.cassandra; }; systemd.services.cassandra = { description = "Apache Cassandra service"; after = [ "network.target" ]; environment = commonEnv // { JVM_OPTS = builtins.concatStringsSep " " fullJvmOptions; MAX_HEAP_SIZE = toString cfg.maxHeapSize; HEAP_NEWSIZE = toString cfg.heapNewSize; MALLOC_ARENA_MAX = toString cfg.mallocArenaMax; LOCAL_JMX = if cfg.remoteJmx then "no" else "yes"; JMX_PORT = toString cfg.jmxPort; }; wantedBy = [ "multi-user.target" ]; serviceConfig = { User = cfg.user; Group = cfg.group; ExecStart = "${cfg.package}/bin/cassandra -f"; SuccessExitStatus = 143; }; }; systemd.services.cassandra-full-repair = { description = "Perform a full repair on this Cassandra node"; after = [ "cassandra.service" ]; requires = [ "cassandra.service" ]; environment = commonEnv; serviceConfig = { User = cfg.user; Group = cfg.group; ExecStart = concatStringsSep " " ([ "${cfg.package}/bin/nodetool" "repair" "--full" ] ++ cfg.fullRepairOptions); }; }; systemd.timers.cassandra-full-repair = mkIf (cfg.fullRepairInterval != null) { description = "Schedule full repairs on Cassandra"; wantedBy = [ "timers.target" ]; timerConfig = { OnBootSec = cfg.fullRepairInterval; OnUnitActiveSec = cfg.fullRepairInterval; Persistent = true; }; }; systemd.services.cassandra-incremental-repair = { description = "Perform an incremental repair on this cassandra node."; after = [ "cassandra.service" ]; requires = [ "cassandra.service" ]; environment = commonEnv; serviceConfig = { User = cfg.user; Group = cfg.group; ExecStart = concatStringsSep " " ([ "${cfg.package}/bin/nodetool" "repair" ] ++ cfg.incrementalRepairOptions); }; }; systemd.timers.cassandra-incremental-repair = mkIf (cfg.incrementalRepairInterval != null) { description = "Schedule incremental repairs on Cassandra"; wantedBy = [ "timers.target" ]; timerConfig = { OnBootSec = cfg.incrementalRepairInterval; OnUnitActiveSec = cfg.incrementalRepairInterval; Persistent = true; }; }; }; meta.maintainers = with lib.maintainers; [ roberth ]; }