cloud/bmaas/bmdb/scruffy: initialize, implement BMDB metrics
This creates a new BMaaS component, Scruffy the Janitor.
Scruffy will run a bunch of housekeeping jobs that aren't tied to a
particular provider or even region. Currently Scruffy just collects BMDB
metrics by periodically polling the BMDB SQL database.
Change-Id: Icafa714811757eaaf31fed43184ded8512bde067
Reviewed-on: https://review.monogon.dev/c/monogon/+/1819
Tested-by: Jenkins CI
Reviewed-by: Tim Windelschmidt <tim@monogon.tech>
diff --git a/cloud/bmaas/bmdb/model/interfaces.go b/cloud/bmaas/bmdb/model/interfaces.go
new file mode 100644
index 0000000..9c8f601
--- /dev/null
+++ b/cloud/bmaas/bmdb/model/interfaces.go
@@ -0,0 +1,73 @@
+package model
+
+import "context"
+
+// MetricValue is a prometheus-style labeled numerical metric value. In other
+// words, it's a number accompanied by string key/value pairs.
+type MetricValue struct {
+ Count int64
+ Labels map[string]string
+}
+
+// WrapSimpleMetric turns a SQL model function which returns a single number into
+// a function which returns one-length MetricValue list with no labels.
+func WrapSimpleMetric(fn func(*Queries, context.Context) (int64, error)) func(*Queries, context.Context) ([]MetricValue, error) {
+ return func(q *Queries, ctx context.Context) ([]MetricValue, error) {
+ v, err := fn(q, ctx)
+ if err != nil {
+ return nil, err
+ }
+ return []MetricValue{
+ {
+ Count: v,
+ Labels: nil,
+ },
+ }, nil
+ }
+}
+
+// A SQLMetricRow is a row that is the result of some kind of SQL 'metric query'.
+// For each such query we define in our *.sql files, a corresponding
+// implementation exists here.
+type SQLMetricRow interface {
+ Value() MetricValue
+}
+
+// Value implements SQLMetricRow for a row of the result of the
+// CountActiveBackoffs SQL metric query.
+func (c CountActiveBackoffsRow) Value() MetricValue {
+ return MetricValue{
+ Count: c.Count,
+ Labels: map[string]string{
+ "process": string(c.Process),
+ },
+ }
+}
+
+// Value implements SQLMetricRow for a row of the result of the
+// CountActiveWork SQL metric query.
+func (c CountActiveWorkRow) Value() MetricValue {
+ return MetricValue{
+ Count: c.Count,
+ Labels: map[string]string{
+ "process": string(c.Process),
+ },
+ }
+}
+
+// WrapLabeledMetric turns a SQL model function which returns a list of rows
+// implementing SQLMetricRow into a function which returns a list of MetricValues
+// with labels corresponding to the data returned in the rows.
+func WrapLabeledMetric[M SQLMetricRow](fn func(*Queries, context.Context) ([]M, error)) func(*Queries, context.Context) ([]MetricValue, error) {
+ return func(q *Queries, ctx context.Context) ([]MetricValue, error) {
+ v, err := fn(q, ctx)
+ if err != nil {
+ return nil, err
+ }
+ res := make([]MetricValue, len(v))
+ for i, vv := range v {
+ res[i] = vv.Value()
+ }
+ return res, nil
+ }
+}