Add Clickhouse service (#85)

doc/services-flake/clickhouse.md

@@ -0,0 +1,27 @@
+# Clickhouse
+
+## Getting Started
+
+```nix
+# In `perSystem.process-compose.<name>`
+{
+  services.clickhouse."clickhouse-1".enable = true;
+}
+```
+
+## Tips & Tricks
+
+### Change the HTTP default port
+
+Clickhouse has [HTTP Interface](https://clickhouse.com/docs/en/interfaces/http) that is enabled by default on port 8123. To change the default port, use the `extraConfig` option:
+
+```nix
+{
+  services.clickhouse."clickhouse-1" = {
+    enable = true;
+    extraConfig = ''
+      http_port: 9050
+    '';
+  };
+}
+```

doc/services-flake/services.md

@@ -8,6 +8,7 @@ short-title: Services
 > This list denotes the progress of documentation, not implementation. See full list of implemented services at [gh].
 
 - [ ] Apache Kafka
+- [ ] [[clickhouse]]#
 - [ ] Elasticsearch
 - [ ] MySQL
 - [ ] Nginx

nix/clickhouse.nix

@@ -0,0 +1,87 @@
+# Based on: https://github.com/cachix/devenv/blob/main/src/modules/services/clickhouse.nix
+{ pkgs, lib, name, config, ... }:
+let
+  inherit (lib) types;
+in
+{
+  options = {
+    enable = lib.mkEnableOption name;
+
+    package = lib.mkOption {
+      type = types.package;
+      description = "Which package of clickhouse to use";
+      default = pkgs.clickhouse;
+      defaultText = lib.literalExpression "pkgs.clickhouse";
+    };
+
+    port = lib.mkOption {
+      type = types.int;
+      description = "Which port to run clickhouse on. This port is for `clickhouse-client` program";
+      default = 9000;
+    };
+
+    dataDir = lib.mkOption {
+      type = types.str;
+      default = "./data/${name}";
+      description = "The clickhouse data directory";
+    };
+
+    extraConfig = lib.mkOption {
+      type = types.lines;
+      description = "Additional configuration to be appended to `clickhouse-config.yaml`.";
+      default = "";
+    };
+
+    outputs.settings = lib.mkOption {
+      type = types.deferredModule;
+      internal = true;
+      readOnly = true;
+      default = {
+        processes = {
+          "${name}" =
+            let
+              clickhouseConfig = pkgs.writeText "clickhouse-config.yaml" ''
+                logger:
+                  level: warning
+                  console: 1
+                tcp_port: ${toString config.port}
+                default_profile: default
+                default_database: default
+                path: ${config.dataDir}/clickhouse
+                tmp_path: ${config.dataDir}/clickhouse/tmp
+                user_files_path: ${config.dataDir}/clickhouse/user_files
+                format_schema_path: ${config.dataDir}/clickhouse/format_schemas
+                user_directories:
+                  users_xml:
+                    path: ${config.package}/etc/clickhouse-server/users.xml
+                ${config.extraConfig}
+              '';
+              startScript = pkgs.writeShellApplication {
+                name = "start-clickhouse";
+                runtimeInputs = [ config.package ];
+                text = ''
+                  clickhouse-server --config-file=${clickhouseConfig}
+                '';
+              };
+            in
+            {
+              command = "${lib.getExe startScript}";
+
+              readiness_probe = {
+                exec.command = ''${config.package}/bin/clickhouse-client --query "SELECT 1" --port ${builtins.toString config.port}'';
+                initial_delay_seconds = 2;
+                period_seconds = 10;
+                timeout_seconds = 4;
+                success_threshold = 1;
+                failure_threshold = 5;
+              };
+              namespace = name;
+
+              # https://github.com/F1bonacc1/process-compose#-auto-restart-if-not-healthy
+              availability.restart = "on_failure";
+            };
+        };
+      };
+    };
+  };
+}

nix/clickhouse_test.nix

@@ -0,0 +1,35 @@
+{ pkgs, config, ... }: {
+  services.clickhouse."clickhouse" = {
+    enable = true;
+    extraConfig = ''
+      http_port: 9050
+    '';
+  };
+
+  settings.processes.test =
+    let
+      cfg = config.services.clickhouse."clickhouse";
+    in
+    {
+      command = pkgs.writeShellApplication {
+        runtimeInputs = [ cfg.package pkgs.gnugrep pkgs.curl ];
+        text =
+          let
+            # Tests based on: https://github.com/NixOS/nixpkgs/blob/master/nixos/tests/clickhouse.nix
+            tableDDL = pkgs.writeText "ddl.sql" "CREATE TABLE `demo` (`value` FixedString(10)) engine = MergeTree PARTITION BY value ORDER BY tuple();";
+            insertQuery = pkgs.writeText "insert.sql" "INSERT INTO `demo` (`value`) VALUES ('foo');";
+            selectQuery = pkgs.writeText "select.sql" "SELECT * from `demo`";
+          in
+          ''
+            clickhouse-client < ${tableDDL}
+            clickhouse-client < ${insertQuery}
+            clickhouse-client < ${selectQuery} | grep foo
+
+            # Test clickhouse http port
+            curl http://localhost:9050 | grep Ok
+          '';
+        name = "clickhouse-test";
+      };
+      depends_on."clickhouse".condition = "process_healthy";
+    };
+}

nix/default.nix

@@ -5,6 +5,7 @@ in
 {
   imports = builtins.map multiService [
     ./apache-kafka.nix
+    ./clickhouse.nix
     ./elasticsearch.nix
     ./mysql.nix
     ./nginx.nix

test/flake.nix

@@ -38,6 +38,7 @@
           in
           builtins.listToAttrs (builtins.map mkPackageFor [
             ../nix/apache-kafka_test.nix
+            ../nix/clickhouse_test.nix
             ../nix/elasticsearch_test.nix
             ../nix/mysql_test.nix
             ../nix/nginx_test.nix