Support publishing build events

Add a table to store events, which have a type and a JSON blob. These can be
used to record changes, this commit inserts events when new builds are
created, and when the status of builds change.

The EventsOutbox table is then used to track when events have been sent
out. This is done through the new cuirass-send-events script.

* Makefile.am (bin_SCRIPTS): Add bin/cuirass-send-events.
(dist_pkgmodule_DATA): Add src/cuirass/send-events.scm.
(dist_sql_DATA): Add src/sql/upgrade-5.sql.
(EXTRA_DIST): bin/cuirass-send-events.in.
(bin/cuirass-send-events): New rule.
* bin/cuirass-send-events.in: New file.
* src/cuirass/send-events.scm: New file.
* src/sql/upgrade-5.sql: New file.
* src/cuirass/database.scm (changes-count): New procedure.
(db-update-build-status!): Call db-add-event after updating the build status.
(db-add-event): New procedure.
(db-add-build): Insert an event when a new build is inserted.
(db-delete-events-with-ids-<=-to): New procedure.
* src/schema.sql (Events): New table.

1 files changed, 7 insertions, 0 deletions

diff --git a/src/schema.sql b/src/schema.sql
index a9e4a6a..cd67530 100644
--- a/src/schema.sql
+++ b/src/schema.sql
@@ -64,6 +64,13 @@ CREATE TABLE Builds (
   FOREIGN KEY (evaluation) REFERENCES Evaluations (id)
 );
 
+CREATE TABLE Events (
+  id            INTEGER PRIMARY KEY,
+  type          TEXT NOT NULL,
+  timestamp     INTEGER NOT NULL,
+  event_json    TEXT NOT NULL
+);
+
 -- Create indexes to speed up common queries, in particular those
 -- corresponding to /api/latestbuilds and /api/queue HTTP requests.
 CREATE INDEX Builds_index ON Builds(job_name, system, status ASC, timestamp ASC, derivation, evaluation, stoptime DESC);