Save the build machine.

* src/sql/upgrade-17.sql: New file.
* Makefile.am (dist_sql_DATA): Add it.
* src/schema.sql (Builds): Add "machine" field.
* src/cuirass/database.scm (db-update-build-machine!): New procedure.
* src/cuirass/base.scm (handle-build-event): Use it to record the machine
performing the build.

Makefile.am

@@ -85,7 +85,8 @@ dist_sql_DATA = 				\
   src/sql/upgrade-13.sql			\
   src/sql/upgrade-14.sql			\
   src/sql/upgrade-15.sql			\
-  src/sql/upgrade-16.sql
+  src/sql/upgrade-16.sql			\
+  src/sql/upgrade-17.sql
 
 dist_css_DATA =					\
   src/static/css/cuirass.css			\

src/cuirass/base.scm

@@ -583,7 +583,8 @@ updating the database accordingly."
            (db-update-build-status! drv (build-status started)))
          (log-message "bogus build-started event for '~a'" drv)))
     (('build-remote drv host _ ...)
-     (log-message "'~a' offloaded to '~a'" drv host))
+     (log-message "'~a' offloaded to '~a'" drv host)
+     (db-update-build-machine! drv host))
     (('build-succeeded drv _ ...)
      (if (valid? drv)
          (begin

src/cuirass/database.scm

@@ -60,6 +60,7 @@
             db-add-build-product
             db-register-builds
             db-update-build-status!
+            db-update-build-machine!
             db-get-output
             db-get-inputs
             db-get-build
@@ -802,6 +803,12 @@ log file for DRV."
                             (#:event      . ,(assq-ref status-names
                                                        status)))))))))
 
+(define* (db-update-build-machine! drv machine)
+  "Update the database so that DRV's machine is MACHINE."
+  (with-db-writer-worker-thread db
+    (sqlite-exec db "UPDATE Builds SET machine=" machine
+                 "WHERE derivation=" drv ";")))
+
 (define (db-get-output path)
   "Retrieve the OUTPUT for PATH."
   (with-db-worker-thread db

src/schema.sql

@@ -61,6 +61,7 @@ CREATE TABLE Builds (
   evaluation    INTEGER NOT NULL,
   job_name      TEXT NOT NULL,
   system        TEXT NOT NULL,
+  machine       TEXT, --optional, machine performing the build.
   nix_name      TEXT NOT NULL,
   log           TEXT NOT NULL,
   status        INTEGER NOT NULL,

src/sql/upgrade-17.sql

+BEGIN TRANSACTION;
+
+ALTER TABLE Builds ADD machine TEXT DEFAULT NULL;
+
+COMMIT;