Add elasticsearch service (#37)

README.md

@@ -20,6 +20,7 @@ TODO
 - [ ] MySQL
 - [x] Redis
 - [x] Redis Cluster
+- [x] Elasticsearch
 - [ ] ...
 
 ## A note on process working directory

nix/default.nix

@@ -37,5 +37,6 @@ in
     ./postgres.nix
     ./redis.nix
     ./redis-cluster.nix
+    ./elasticsearch.nix
   ];
 }

nix/elasticsearch.nix

@@ -0,0 +1,198 @@
+# Based on https://github.com/cachix/devenv/blob/main/src/modules/services/elasticsearch.nix
+{ pkgs, lib, name, config, ... }:
+let
+  inherit (lib) types;
+in
+{
+  options = {
+    description = ''
+      Configure elasticsearch. This will start a single-node cluster by default.
+      Note: 
+      To use elastic search you will need the following inside your `perSystem`, if not already configured:
+      { 
+        _module.args.pkgs = import inputs.nixpkgs {
+            inherit system;
+            # Required for elastic search
+            config.allowUnfree = true;
+          };
+      } 
+    '';
+    enable = lib.mkEnableOption name;
+
+    package = lib.mkPackageOption pkgs "elasticsearch7" { };
+
+    dataDir = lib.mkOption {
+      type = types.str;
+      default = "./data/${name}";
+      description = "Directory where elasticsearch stores its data.";
+    };
+
+    listenAddress = lib.mkOption {
+      description = "Elasticsearch listen address.";
+      default = "127.0.0.1";
+      type = types.str;
+    };
+
+    port = lib.mkOption {
+      description = "Elasticsearch port to listen for HTTP traffic.";
+      default = 9200;
+      type = types.int;
+    };
+
+    tcp_port = lib.mkOption {
+      description = "Elasticsearch port for the node to node communication.";
+      default = 9300;
+      type = types.int;
+    };
+
+    cluster_name = lib.mkOption {
+      description =
+        "Elasticsearch name that identifies your cluster for auto-discovery.";
+      default = "elasticsearch";
+      type = types.str;
+    };
+
+    single_node = lib.mkOption {
+      description = "Start a single-node cluster";
+      default = true;
+      type = types.bool;
+    };
+
+    extraConf = lib.mkOption {
+      description = "Extra configuration for elasticsearch.";
+      default = "";
+      type = types.str;
+      example = ''
+        node.name: "elasticsearch"
+        node.master: true
+        node.data: false
+      '';
+    };
+
+    logging = lib.mkOption {
+      description = "Elasticsearch logging configuration.";
+      default = ''
+        logger.action.name = org.elasticsearch.action
+        logger.action.level = info
+        appender.console.type = Console
+        appender.console.name = console
+        appender.console.layout.type = PatternLayout
+        appender.console.layout.pattern = [%d{ISO8601}][%-5p][%-25c{1.}] %marker%m%n
+        rootLogger.level = info
+        rootLogger.appenderRef.console.ref = console
+      '';
+      type = types.str;
+    };
+
+    extraCmdLineOptions = lib.mkOption {
+      description =
+        "Extra command line options for the elasticsearch launcher.";
+      default = [ ];
+      type = types.listOf types.str;
+    };
+
+    extraJavaOptions = lib.mkOption {
+      description = "Extra command line options for Java.";
+      default = [ ];
+      type = types.listOf types.str;
+      example = [ "-Djava.net.preferIPv4Stack=true" ];
+    };
+
+    plugins = lib.mkOption {
+      description = "Extra elasticsearch plugins";
+      default = [ ];
+      type = types.listOf types.package;
+      example =
+        lib.literalExpression "[ pkgs.elasticsearchPlugins.discovery-ec2 ]";
+    };
+
+    outputs.settings = lib.mkOption {
+      type = types.deferredModule;
+      internal = true;
+      readOnly = true;
+      default = {
+        processes."${name}" =
+          let
+            es7 = builtins.compareVersions config.package.version "7" >= 0;
+
+            esConfig = ''
+              network.host: ${config.listenAddress}
+              cluster.name: ${config.cluster_name}
+              ${lib.optionalString config.single_node "discovery.type: single-node"}
+              http.port: ${toString config.port}
+              transport.port: ${toString config.tcp_port}
+              ${config.extraConf}
+            '';
+
+            elasticsearchYml = pkgs.writeTextFile {
+              name = "elasticsearch.yml";
+              text = esConfig;
+            };
+
+            loggingConfigFilename = "log4j2.properties";
+            loggingConfigFile = pkgs.writeTextFile {
+              name = loggingConfigFilename;
+              text = config.logging;
+            };
+
+            esPlugins = pkgs.buildEnv {
+              name = "elasticsearch-plugins";
+              paths = config.plugins;
+              postBuild = "${pkgs.coreutils}/bin/mkdir -p $out/plugins";
+            };
+
+            startScript = pkgs.writeShellScript "es-startup" ''
+              set -e
+
+              export ES_HOME=$(${pkgs.coreutils}/bin/realpath ${config.dataDir})
+              export ES_JAVA_OPTS="${toString config.extraJavaOptions}"
+              export ES_PATH_CONF="${config.dataDir}/config"
+              mkdir -m 0700 -p "${config.dataDir}"
+              # Install plugins
+              rm -f "${config.dataDir}/plugins"
+              ln -sf ${esPlugins}/plugins "${config.dataDir}/plugins"
+              rm -f "${config.dataDir}/lib"
+              ln -sf ${config.package}/lib "${config.dataDir}/lib"
+              rm -f "${config.dataDir}/modules"
+              ln -sf ${config.package}/modules "${config.dataDir}/modules"
+
+              # Create config dir
+              mkdir -m 0700 -p "${config.dataDir}/config"
+              rm -f "${config.dataDir}/config/elasticsearch.yml"
+              cp ${elasticsearchYml} "${config.dataDir}/config/elasticsearch.yml"
+              rm -f "${config.dataDir}/logging.yml"
+              rm -f "${config.dataDir}/config/${loggingConfigFilename}"
+              cp ${loggingConfigFile} "${config.dataDir}/config/${loggingConfigFilename}"
+
+              mkdir -p "${config.dataDir}/scripts"
+              rm -f "${config.dataDir}/config/jvm.options"
+
+              cp ${config.package}/config/jvm.options "${config.dataDir}/config/jvm.options"
+
+              # Create log dir
+              mkdir -m 0700 -p "${config.dataDir}/logs"
+
+              # Start it
+              exec ${config.package}/bin/elasticsearch ${toString config.extraCmdLineOptions}
+            '';
+
+          in
+          {
+            command = "${startScript}";
+
+            readiness_probe = {
+              exec.command = "${pkgs.curl}/bin/curl -f -k http://${config.listenAddress}:${toString config.port}";
+              initial_delay_seconds = 15;
+              period_seconds = 10;
+              timeout_seconds = 2;
+              success_threshold = 1;
+              failure_threshold = 5;
+            };
+
+            # https://github.com/F1bonacc1/process-compose#-auto-restart-if-not-healthy
+            availability.restart = "on_failure";
+          };
+      };
+    };
+  };
+}

nix/elasticsearch_test.nix

@@ -0,0 +1,14 @@
+{ pkgs, config, ... }: {
+  services.elasticsearch."es1".enable = true;
+  settings.processes.test =
+    {
+      command = pkgs.writeShellApplication {
+        runtimeInputs = [ pkgs.curl ];
+        text = ''
+         curl 127.0.0.1:9200/_cat/health 
+        '';
+        name = "elasticsearch-test";
+      };
+      depends_on."es1".condition = "process_healthy";
+    };
+}

test/flake.nix

@@ -12,7 +12,12 @@
       imports = [
         inputs.process-compose-flake.flakeModule
       ];
-      perSystem = { self', pkgs, lib, ... }: {
+      perSystem = { self', pkgs, system, lib, ... }: {
+        _module.args.pkgs = import inputs.nixpkgs {
+          inherit system;
+          # Required for elastic search
+          config.allowUnfree = true;
+        };
         process-compose = {
           postgres = {
             imports = [
@@ -32,6 +37,12 @@
               ../nix/redis-cluster_test.nix
             ];
           };
+          elasticsearch = {
+            imports = [
+              inputs.services-flake.processComposeModules.default
+              ../nix/elasticsearch_test.nix
+            ];
+          };
         };
       };
     };