Unistore: Reuse MySQL and Postgres Grafana core config instead of the object (#94223)

* Reuse MySQL and Postgres Grafana config instead of the object

- Only reuse the Grafana DB object for SQLite. Support for SQLite will be added in a different PR
- Fail when reusing the Grafana DB object if it is using DB instrumentation
- In the case that we have to reuse a Grafana DB with its instrumentation, fail with an error that describes a workaround
- Add regression tests to reproduce incident 2144

* remove temp file

* fix linter

* fix linter x2

* fix linter x3

pkg/storage/unified/sql/db/dbimpl/dbimpl_test.go

@@ -0,0 +1,159 @@
+package dbimpl
+
+import (
+	"context"
+	"database/sql"
+	"net/http"
+	"testing"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/otel/trace"
+	traceNoop "go.opentelemetry.io/otel/trace/noop"
+	ini "gopkg.in/ini.v1"
+
+	"github.com/grafana/grafana/pkg/bus"
+	infraDB "github.com/grafana/grafana/pkg/infra/db"
+	"github.com/grafana/grafana/pkg/infra/tracing"
+	"github.com/grafana/grafana/pkg/services/sqlstore"
+	"github.com/grafana/grafana/pkg/setting"
+)
+
+type (
+	// cfgSectionMap represents an INI section, mapping from an INI key to an
+	// INI value.
+	cfgSectionMap = map[string]string
+	// cfgMap is a map from INI section name to INI section contents.
+	cfgMap = map[string]cfgSectionMap
+)
+
+// setupDBForGrafana modifies `m` in the following way:
+//
+//	[database]
+//	type = sqlite3
+//	path = unique-random-path
+//
+// After that, it initializes a temporary SQLite filesystem-backed database that
+// is later deleted when the test finishes.
+func setupDBForGrafana(t *testing.T, ctx context.Context, m cfgMap) {
+	dbSection, ok := m["database"]
+	if !ok {
+		dbSection = cfgSectionMap{}
+		m["database"] = dbSection
+	}
+	dbSection["type"] = "sqlite3"
+	dbSection["path"] = t.TempDir() + "/" + uuid.New().String()
+
+	db, err := sql.Open("sqlite3", "file:"+dbSection["path"])
+	require.NoError(t, err)
+
+	_, err = db.ExecContext(ctx, `
+		CREATE TABLE user (
+			id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
+			version INTEGER NOT NULL,
+			login TEXT NOT NULL,
+			email TEXT NOT NULL,
+			name TEXT NULL,
+			password TEXT NULL,
+			salt TEXT NULL,
+			rands TEXT NULL,
+			company TEXT NULL,
+			org_id INTEGER NOT NULL,
+			is_admin INTEGER NOT NULL,
+			email_verified INTEGER NULL,
+			theme TEXT NULL,
+			created DATETIME NOT NULL,
+			updated DATETIME NOT NULL,
+			help_flags1 INTEGER NOT NULL DEFAULT 0,
+			last_seen_at DATETIME NULL,
+			is_disabled INTEGER NOT NULL DEFAULT 0,
+			is_service_account BOOLEAN DEFAULT 0,
+			uid TEXT NULL
+		);
+		CREATE TABLE org (
+			id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
+			version INTEGER NOT NULL,
+			name TEXT NOT NULL,
+			address1 TEXT NULL,
+			address2 TEXT NULL,
+			city TEXT NULL,
+			state TEXT NULL,
+			zip_code TEXT NULL,
+			country TEXT NULL,
+			billing_email TEXT NULL,
+			created DATETIME NOT NULL,
+			updated DATETIME NOT NULL
+		);
+		CREATE TABLE org_user (
+			id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
+			org_id INTEGER NOT NULL,
+			user_id INTEGER NOT NULL,
+			role TEXT NOT NULL,
+			created DATETIME NOT NULL,
+			updated DATETIME NOT NULL
+		);
+	`)
+	require.NoError(t, err)
+}
+
+func newTestInfraDB(t *testing.T, m cfgMap) infraDB.DB {
+	t.Helper()
+	// nil migrations means no migrations
+	sqlstoreDB, err := sqlstore.ProvideService(
+		newCfgFromIniMap(t, m), // *setting.Cfg
+		featureTogglesNop{},    // featuremgmt.FeatureToggles
+		nil,                    // registry.DatabaseMigrator
+		nopBus{},               // github.com/grafana/grafana/pkg/bus.Bus
+		newNopTestGrafanaTracer(),
+	)
+	require.NoError(t, err)
+
+	return sqlstoreDB
+}
+
+func newCfgFromIniMap(t *testing.T, m cfgMap) *setting.Cfg {
+	t.Helper()
+	cfg, err := setting.NewCfgFromINIFile(newTestINIFile(t, m))
+	require.NoError(t, err)
+	return cfg
+}
+
+func newTestINIFile(t *testing.T, m cfgMap) *ini.File {
+	t.Helper()
+	f := ini.Empty()
+	for sectionName, kvs := range m {
+		section, err := f.NewSection(sectionName)
+		require.NoError(t, err)
+		for k, v := range kvs {
+			_, err := section.NewKey(k, v)
+			require.NoError(t, err)
+		}
+	}
+	return f
+}
+
+type (
+	testGrafanaTracer struct {
+		trace.Tracer
+	}
+	featureTogglesNop struct{}
+	nopBus            struct{}
+)
+
+func (testGrafanaTracer) Inject(context.Context, http.Header, trace.Span) {}
+func newNopTestGrafanaTracer() tracing.Tracer {
+	return testGrafanaTracer{traceNoop.NewTracerProvider().Tracer("test")}
+}
+
+func (featureTogglesNop) IsEnabled(context.Context, string) bool {
+	return false
+}
+func (featureTogglesNop) IsEnabledGlobally(string) bool {
+	return false
+}
+func (featureTogglesNop) GetEnabled(context.Context) map[string]bool {
+	return map[string]bool{}
+}
+
+func (nopBus) Publish(context.Context, bus.Msg) error { return nil }
+func (nopBus) AddEventListener(bus.HandlerFunc)       {}