Ported/merged properties from the TUD configuration's hydra-module

hydra-module.nix

@@ -13,16 +13,19 @@ let
       max_servers 25
     '';
 
-  env = ''export NIX_REMOTE=daemon ''
-      + ''HYDRA_DBI="${cfg.dbi}" ''
-      + ''HYDRA_CONFIG=${cfg.baseDir}/data/hydra.conf ''
-      + ''HYDRA_DATA=${cfg.baseDir}/data ''
-      + ''HYDRA_PORT="${toString cfg.port}" ''
-      + (if cfg.logo != null
-         then ''HYDRA_LOGO="${cfg.logo}" ''
-         else "")
-      + ''HYDRA_TRACKER="${cfg.tracker}" ;'';
-
+  env =
+    { NIX_REMOTE = "daemon";
+      HYDRA_DBI = cfg.dbi;
+      HYDRA_CONFIG = "${cfg.baseDir}/data/hydra.conf";
+      HYDRA_DATA = "${cfg.baseDir}/data";
+      HYDRA_PORT = "${toString cfg.port}";
+      OPENSSL_X509_CERT_FILE = "/etc/ssl/certs/ca-bundle.crt";
+    };
+  
+  serverEnv = env //
+    { HYDRA_LOGO = if cfg.logo != null then cfg.logo else "";
+      HYDRA_TRACKER = cfg.tracker;
+    };
 in
 
 {
@@ -60,7 +63,7 @@ in
       };
 
       hydra = mkOption {
-        default = pkgs.hydra;
+        #default = pkgs.hydra;
         description = ''
           Location of hydra
         '';
@@ -121,6 +124,13 @@ in
           If hydra upstart jobs should start automatically.
         '';
       };
+      
+      useWAL = mkOption {
+        default = true;
+        description = ''
+          Whether to use SQLite's Write-Ahead Logging, which may improve performance.
+        '';
+      };
 
     };
 
@@ -156,46 +166,71 @@ in
       build-cache-failure = true
 
       build-poll-interval = 10
+      
+      # Online log compression makes it impossible to get the tail of
+      # builds that are in progress.
+      build-compress-log = false
 
-      use-sqlite-wal = false
+      use-sqlite-wal = ${if cfg.useWAL then "true" else "false"}
     '';
 
-    jobs.hydra_init =
-      { description = "hydra-init";
-        startOn = "started network-interfaces";
-        preStart = ''
+    jobs."hydra-init" =
+      { wantedBy = [ "multi-user.target" ];
+        script = ''
           mkdir -p ${cfg.baseDir}/data
           chown ${cfg.user} ${cfg.baseDir}/data
           ln -sf ${hydraConf} ${cfg.baseDir}/data/hydra.conf
         '';
-        exec = ''
-          echo done
-        '';
+        task = true;
+      };
+    
+    systemd.services."hydra-server" =
+      { wantedBy = [ "multi-user.target" ];
+        wants = [ "hydra-init.service" ];
+        after = [ "hydra-init.service" ];
+        environment = serverEnv;
+        serviceConfig =
+          { ExecStart = "@${cfg.hydra}/bin/hydra-server hydra-server -f -h \* --max_spare_servers 5 --max_servers 25 --max_requests 100";
+            User = cfg.user;
+            Restart = "always";
+          };
       };
 
-    jobs.hydra_server =
-      { description = "hydra-server";
-        startOn = if cfg.autoStart then "started network-interfaces hydra-init" else "never";
-        exec = ''
-          ${pkgs.su}/bin/su - ${cfg.user} -c '${env} ${cfg.hydra}/bin/hydra-server > ${cfg.baseDir}/data/server.log 2>&1'
-        '';
+    systemd.services."hydra-queue-runner" =
+      { wantedBy = [ "multi-user.target" ];
+        wants = [ "hydra-init.service" ];
+        after = [ "hydra-init.service" "network.target" ];
+        path = [ pkgs.nettools pkgs.ssmtp ];
+        environment = env;
+        serviceConfig =
+          { ExecStartPre = "${cfg.hydra}/bin/hydra-queue-runner --unlock";
+            ExecStart = "@${cfg.hydra}/bin/hydra-queue-runner hydra-queue-runner";
+            User = cfg.user;
+            Restart = "always";
+          };
       };
 
-    jobs.hydra_queue_runner =
-      { description = "hydra-queue-runner";
-        startOn = if cfg.autoStart then "started network-interfaces hydra-init" else "never";
-        preStart = "${pkgs.su}/bin/su - ${cfg.user} -c '${env} ${cfg.hydra}/bin/hydra-queue-runner --unlock'";
-        exec = ''
-          ${pkgs.su}/bin/su - ${cfg.user} -c '${env} nice -n 8 ${cfg.hydra}/bin/hydra-queue-runner > ${cfg.baseDir}/data/queue-runner.log 2>&1'
-        '';
+    systemd.services."hydra-evaluator" =
+      { wantedBy = [ "multi-user.target" ];
+        wants = [ "hydra-init.service" ];
+        after = [ "hydra-init.service" "network.target" ];
+        path = [ pkgs.nettools pkgs.ssmtp ];
+        environment = env;
+        serviceConfig =
+          { ExecStart = "@${cfg.hydra}/bin/hydra-evaluator hydra-evaluator";
+            User = cfg.user;
+            Restart = "always";
+          };
       };
 
-    jobs.hydra_evaluator =
-      { description = "hydra-evaluator";
-        startOn = if cfg.autoStart then "started network-interfaces hydra-init" else "never";
-        exec = ''
-          ${pkgs.su}/bin/su - ${cfg.user} -c '${env} nice -n 5 ${cfg.hydra}/bin/hydra-evaluator > ${cfg.baseDir}/data/evaluator.log 2>&1'
-        '';
+    systemd.services."hydra-update-gc-roots" =
+      { wants = [ "hydra-init.service" ];
+        after = [ "hydra-init.service" ];
+        environment = env;
+        serviceConfig =
+          { ExecStart = "@${cfg.hydra}/bin/hydra-update-gc-roots hydra-update-gc-roots";
+            User = cfg.user;
+          };
       };
 
     services.cron.systemCronJobs =
@@ -206,23 +241,11 @@ in
           ''
             #! /bin/sh
             if [ $(($(stat -f -c '%a' /nix/store) * $(stat -f -c '%S' /nix/store))) -lt $((${toString cfg.minimumDiskFree} * 1024**3)) ]; then
-          stop hydra_queue_runner
+                stop hydra_queue_runner
+            fi
+            if [ $(($(stat -f -c '%a' /nix/store) * $(stat -f -c '%S' /nix/store))) -lt $((${toString cfg.minimumDiskFreeEvaluator} * 1024**3)) ]; then
+                stop hydra_evaluator
             fi
-        if [ $(($(stat -f -c '%a' /nix/store) * $(stat -f -c '%S' /nix/store))) -lt $((${toString cfg.minimumDiskFreeEvaluator} * 1024**3)) ]; then
-          stop hydra_evaluator
-        fi
-          '';
-
-        collect = pkgs.writeScript "collect-some-garbage"
-          # Arrange to always have at least 100 GiB free.
-          '' #!/bin/sh -e
-             available="$(df -B1 /nix/store | tail -n 1 | awk '{ print $4 }')"
-             target="$((100 * 1024**3))"
-             to_free="$(($available > $target ? 200 * 1024**2 : $target - $available))"
-
-             echo "$available B available, and targeting $target B available"
-             echo "thus, freeing $to_free B"
-             exec "${pkgs.nix}/bin/nix-collect-garbage" --max-freed "$to_free"
           '';
 
         compressLogs = pkgs.writeScript "compress-logs" ''
@@ -231,13 +254,9 @@ in
            find /nix/var/log/nix/drvs -type f -a ! -newer r -name '*.drv' | xargs bzip2 -v
          '';
       in
-        [ "15 03 * * * root  ${collect} &> ${cfg.baseDir}/data/gc.log"
-          "15 13 * * * root  ${collect} &> ${cfg.baseDir}/data/gc.log"
-
-          "*/5 * * * * root  ${checkSpace} &> ${cfg.baseDir}/data/checkspace.log"
-
+        [ "*/5 * * * * root  ${checkSpace} &> ${cfg.baseDir}/data/checkspace.log"
           "15 5 * * * root  ${compressLogs} &> ${cfg.baseDir}/data/compress.log"
-          "15 02 * * * ${cfg.user} ${env} ${cfg.hydra}/bin/hydra-update-gc-roots &> ${cfg.baseDir}/data/gc-roots.log"
+          "15 2 * * * root  ${pkgs.systemd}/bin/systemctl start hydra-update-gc-roots.service"
         ];
   };
 }