Determine latest chosen preset using latest non-null preset selection

See https://github.com/coder/internal/issues/398

Signed-off-by: Danny Kopping <danny@coder.com>

coderd/database/dump.sql

@@ -1878,7 +1878,8 @@ SELECT
     NULL::timestamp with time zone AS next_start_at,
     NULL::uuid AS agent_id,
     NULL::workspace_agent_lifecycle_state AS lifecycle_state,
-    NULL::timestamp with time zone AS ready_at;
+    NULL::timestamp with time zone AS ready_at,
+    NULL::uuid AS current_preset_id;
 
 CREATE TABLE workspace_proxies (
     id uuid NOT NULL,
@@ -2472,6 +2473,34 @@ CREATE OR REPLACE VIEW workspace_prebuilds AS
              JOIN workspace_agents wa ON ((wa.resource_id = wr.id)))
           WHERE (w.owner_id = 'c42fdf75-3097-471c-8c33-fb52454d81c0'::uuid)
           GROUP BY w.id, wa.id
+        ), current_presets AS (
+         SELECT w.id AS prebuild_id,
+            lps.template_version_preset_id
+           FROM (workspaces w
+             JOIN ( SELECT wb.id,
+                    wb.created_at,
+                    wb.updated_at,
+                    wb.workspace_id,
+                    wb.template_version_id,
+                    wb.build_number,
+                    wb.transition,
+                    wb.initiator_id,
+                    wb.provisioner_state,
+                    wb.job_id,
+                    wb.deadline,
+                    wb.reason,
+                    wb.daily_cost,
+                    wb.max_deadline,
+                    wb.template_version_preset_id
+                   FROM (( SELECT tv.template_id,
+                            wbmax_1.workspace_id,
+                            max(wbmax_1.build_number) AS max_build_number
+                           FROM (workspace_builds wbmax_1
+                             JOIN template_versions tv ON ((tv.id = wbmax_1.template_version_id)))
+                          WHERE (wbmax_1.template_version_preset_id IS NOT NULL)
+                          GROUP BY tv.template_id, wbmax_1.workspace_id) wbmax
+                     JOIN workspace_builds wb ON (((wb.workspace_id = wbmax.workspace_id) AND (wb.build_number = wbmax.max_build_number))))) lps ON ((lps.workspace_id = w.id)))
+          WHERE (w.owner_id = 'c42fdf75-3097-471c-8c33-fb52454d81c0'::uuid)
         )
  SELECT p.id,
     p.created_at,
@@ -2491,9 +2520,11 @@ CREATE OR REPLACE VIEW workspace_prebuilds AS
     p.next_start_at,
     a.agent_id,
     a.lifecycle_state,
-    a.ready_at
+    a.ready_at,
-   FROM (all_prebuilds p
+    cp.template_version_preset_id AS current_preset_id
-     LEFT JOIN workspace_agents a ON ((a.workspace_id = p.id)));
+   FROM ((all_prebuilds p
+     LEFT JOIN workspace_agents a ON ((a.workspace_id = p.id)))
+     JOIN current_presets cp ON ((cp.prebuild_id = p.id)));
 
 CREATE TRIGGER inhibit_enqueue_if_disabled BEFORE INSERT ON notification_messages FOR EACH ROW EXECUTE FUNCTION inhibit_enqueue_if_disabled();
 

coderd/database/migrations/000297_prebuilds.up.sql

@@ -30,19 +30,45 @@ FROM (SELECT tv.template_id,
 	);
 
 CREATE VIEW workspace_prebuilds AS
-WITH all_prebuilds AS (SELECT w.*
+WITH
+	-- All workspaces owned by the "prebuilds" user.
+	all_prebuilds AS (SELECT w.*
 					  FROM workspaces w
 					  WHERE w.owner_id = 'c42fdf75-3097-471c-8c33-fb52454d81c0'),
+	-- All workspace agents belonging to the workspaces owned by the "prebuilds" user.
 	workspace_agents AS (SELECT w.id AS workspace_id, wa.id AS agent_id, wa.lifecycle_state, wa.ready_at
 						 FROM workspaces w
 								  INNER JOIN workspace_latest_build wlb ON wlb.workspace_id = w.id
 								  INNER JOIN workspace_resources wr ON wr.job_id = wlb.job_id
 								  INNER JOIN workspace_agents wa ON wa.resource_id = wr.id
 						 WHERE w.owner_id = 'c42fdf75-3097-471c-8c33-fb52454d81c0'
-						  GROUP BY w.id, wa.id)
+						 GROUP BY w.id, wa.id),
-SELECT p.*, a.agent_id, a.lifecycle_state, a.ready_at
+	-- We can't rely on the template_version_preset_id in the workspace_builds table because this value is only set on the
+	-- initial workspace creation. Subsequent stop/start transitions will not have a value for template_version_preset_id,
+	-- and therefore we can't rely on (say) the latest build's chosen template_version_preset_id.
+	--
+	-- See https://github.com/coder/internal/issues/398
+	current_presets AS (SELECT w.id AS prebuild_id, lps.template_version_preset_id
+						FROM workspaces w
+								 INNER JOIN (
+							-- The latest workspace build which had a preset explicitly selected
+							SELECT wb.*
+							FROM (SELECT tv.template_id,
+										 wbmax.workspace_id,
+										 MAX(wbmax.build_number) as max_build_number
+								  FROM workspace_builds wbmax
+										   JOIN template_versions tv ON (tv.id = wbmax.template_version_id)
+								  WHERE wbmax.template_version_preset_id IS NOT NULL
+								  GROUP BY tv.template_id, wbmax.workspace_id) wbmax
+									 JOIN workspace_builds wb ON (
+								wb.workspace_id = wbmax.workspace_id
+									AND wb.build_number = wbmax.max_build_number
+								)) lps ON lps.workspace_id = w.id
+						WHERE w.owner_id = 'c42fdf75-3097-471c-8c33-fb52454d81c0')
+SELECT p.*, a.agent_id, a.lifecycle_state, a.ready_at, cp.template_version_preset_id AS current_preset_id
 FROM all_prebuilds p
-		 LEFT JOIN workspace_agents a ON a.workspace_id = p.id;
+		 LEFT JOIN workspace_agents a ON a.workspace_id = p.id
+		 INNER JOIN current_presets cp ON cp.prebuild_id = p.id;
 
 CREATE VIEW workspace_prebuild_builds AS
 SELECT *

coderd/database/models.go

@@ -3489,6 +3489,7 @@ type WorkspacePrebuild struct {
 	AgentID           uuid.NullUUID                    `db:"agent_id" json:"agent_id"`
 	LifecycleState    NullWorkspaceAgentLifecycleState `db:"lifecycle_state" json:"lifecycle_state"`
 	ReadyAt           sql.NullTime                     `db:"ready_at" json:"ready_at"`
+	CurrentPresetID   uuid.NullUUID                    `db:"current_preset_id" json:"current_preset_id"`
 }
 
 type WorkspacePrebuildBuild struct {

coderd/database/queries.sql.go

@@ -5484,19 +5484,23 @@ func (q *sqlQuerier) GetPrebuildsInProgress(ctx context.Context) ([]GetPrebuilds
 
 const getRunningPrebuilds = `-- name: GetRunningPrebuilds :many
 SELECT p.id               AS workspace_id,
+       p.name             AS workspace_name,
        p.template_id,
        b.template_version_id,
        tvp_curr.id        AS current_preset_id,
        tvp_desired.id     AS desired_preset_id,
+       -- TODO: just because a prebuild is in a ready state doesn't mean it's eligible; if the prebuild is due to be
+       --       deleted to reconcile state then it MUST NOT be eligible for claiming. We'll need some kind of lock here.
        CASE
            WHEN p.lifecycle_state = 'ready'::workspace_agent_lifecycle_state THEN TRUE
-		   ELSE FALSE END AS eligible
+           ELSE FALSE END AS ready,
+       p.created_at
 FROM workspace_prebuilds p
          INNER JOIN workspace_latest_build b ON b.workspace_id = p.id
          INNER JOIN provisioner_jobs pj ON b.job_id = pj.id
          INNER JOIN templates t ON p.template_id = t.id
          LEFT JOIN template_version_presets tvp_curr
-				   ON tvp_curr.id = b.template_version_preset_id
+                   ON tvp_curr.id = p.current_preset_id -- See https://github.com/coder/internal/issues/398.
          LEFT JOIN template_version_presets tvp_desired
                    ON tvp_desired.template_version_id = t.active_version_id
 WHERE (b.transition = 'start'::workspace_transition
@@ -5509,11 +5513,13 @@ WHERE (b.transition = 'start'::workspace_transition
 
 type GetRunningPrebuildsRow struct {
 	WorkspaceID       uuid.UUID     `db:"workspace_id" json:"workspace_id"`
+	WorkspaceName     string        `db:"workspace_name" json:"workspace_name"`
 	TemplateID        uuid.UUID     `db:"template_id" json:"template_id"`
 	TemplateVersionID uuid.UUID     `db:"template_version_id" json:"template_version_id"`
 	CurrentPresetID   uuid.NullUUID `db:"current_preset_id" json:"current_preset_id"`
 	DesiredPresetID   uuid.NullUUID `db:"desired_preset_id" json:"desired_preset_id"`
-	Eligible          bool          `db:"eligible" json:"eligible"`
+	Ready             bool          `db:"ready" json:"ready"`
+	CreatedAt         time.Time     `db:"created_at" json:"created_at"`
 }
 
 func (q *sqlQuerier) GetRunningPrebuilds(ctx context.Context) ([]GetRunningPrebuildsRow, error) {
@@ -5527,11 +5533,13 @@ func (q *sqlQuerier) GetRunningPrebuilds(ctx context.Context) ([]GetRunningPrebu
 		var i GetRunningPrebuildsRow
 		if err := rows.Scan(
 			&i.WorkspaceID,
+			&i.WorkspaceName,
 			&i.TemplateID,
 			&i.TemplateVersionID,
 			&i.CurrentPresetID,
 			&i.DesiredPresetID,
-			&i.Eligible,
+			&i.Ready,
+			&i.CreatedAt,
 		); err != nil {
 			return nil, err
 		}

coderd/database/queries/prebuilds.sql

@@ -1,18 +1,22 @@
 -- name: GetRunningPrebuilds :many
 SELECT p.id               AS workspace_id,
+       p.name             AS workspace_name,
        p.template_id,
        b.template_version_id,
        tvp_curr.id        AS current_preset_id,
        tvp_desired.id     AS desired_preset_id,
+       -- TODO: just because a prebuild is in a ready state doesn't mean it's eligible; if the prebuild is due to be
+       --       deleted to reconcile state then it MUST NOT be eligible for claiming. We'll need some kind of lock here.
        CASE
            WHEN p.lifecycle_state = 'ready'::workspace_agent_lifecycle_state THEN TRUE
-		   ELSE FALSE END AS eligible
+           ELSE FALSE END AS ready,
+       p.created_at
 FROM workspace_prebuilds p
          INNER JOIN workspace_latest_build b ON b.workspace_id = p.id
          INNER JOIN provisioner_jobs pj ON b.job_id = pj.id
          INNER JOIN templates t ON p.template_id = t.id
          LEFT JOIN template_version_presets tvp_curr
-				   ON tvp_curr.id = b.template_version_preset_id
+                   ON tvp_curr.id = p.current_preset_id -- See https://github.com/coder/internal/issues/398.
          LEFT JOIN template_version_presets tvp_desired
                    ON tvp_desired.template_version_id = t.active_version_id
 WHERE (b.transition = 'start'::workspace_transition