Remove need for separate remote-write flag for stateless ruler

This removes the need to pass a separate `remote-write` flag to ruler
to enable stateless mode. Instead, we now check if a remote-write config is provided
and automatically enables stateless mode based off that.

Ruler test is also cleaned up to remove unnecessary
tests (i.e those that have been performed by other e2e suites).

Signed-off-by: Michael Okoko <okokomichaels@outlook.com>

cmd/thanos/config.go

@@ -226,13 +226,10 @@ func (ac *alertMgrConfig) registerFlag(cmd extflag.FlagClause) *alertMgrConfig {
 }
 
 type ruleRWConfig struct {
-	remoteWrite bool
-	configPath  *extflag.PathOrContent
+	configPath *extflag.PathOrContent
 }
 
 func (rc *ruleRWConfig) registerFlag(cmd extflag.FlagClause) *ruleRWConfig {
-	cmd.Flag("remote-write", "If true, directs ruler to remote-write evaluated samples to the server configured by 'remote-write.config'.").
-		BoolVar(&rc.remoteWrite)
-	rc.configPath = extflag.RegisterPathOrContent(cmd, "remote-write.config", "YAML config for the remote-write server where samples should be sent to. See https://thanos.io/tip/components/rule.md/#query-api", false)
+	rc.configPath = extflag.RegisterPathOrContent(cmd, "remote-write.config", "YAML config for the remote-write server where samples should be sent to. This automatically enables stateless mode for ruler and no series will be stored in the ruler's TSDB. See https://thanos.io/tip/components/rule.md/#query-api", false)
 	return rc
 }

cmd/thanos/rule.go

@@ -172,8 +172,8 @@ func registerRule(app *extkingpin.App) {
 			return errors.New("--query/--query.sd-files and --query.config* parameters cannot be defined at the same time")
 		}
 
-		// Parse and check remote-write config if it's enabled
-		if conf.rwConfig.remoteWrite {
+		// Parse and check remote-write config and enable stateless mode for ruler.
+		if conf.rwConfig.configPath != nil {
 			conf.rwConfigYAML, err = conf.rwConfig.configPath.Content()
 			if err != nil {
 				return err
@@ -337,7 +337,7 @@ func runRule(
 		db         *tsdb.DB
 	)
 
-	if conf.rwConfig.remoteWrite {
+	if conf.rwConfig.configPath != nil {
 		conf.rwConfigYAML, err = conf.rwConfig.configPath.Content()
 		if err != nil {
 			return err

test/e2e/e2ethanos/services.go

@@ -340,10 +340,14 @@ func NewReceiverWithConfigWatcher(sharedDir string, networkName string, name str
 }
 
 func NewTSDBRuler(sharedDir string, name string, ruleSubDir string, amCfg []alert.AlertmanagerConfig, queryCfg []query.Config) (*Service, error) {
-	return NewRuler(sharedDir, name, ruleSubDir, amCfg, queryCfg, false, remotewrite.Config{})
+	return newRuler(sharedDir, name, ruleSubDir, amCfg, queryCfg, nil)
 }
 
-func NewRuler(sharedDir string, name string, ruleSubDir string, amCfg []alert.AlertmanagerConfig, queryCfg []query.Config, remoteWrite bool, remoteWriteCfg remotewrite.Config) (*Service, error) {
+func NewStatelessRuler(sharedDir string, name string, ruleSubDir string, amCfg []alert.AlertmanagerConfig, queryCfg []query.Config, remoteWriteCfg *remotewrite.Config) (*Service, error) {
+	return newRuler(sharedDir, name, ruleSubDir, amCfg, queryCfg, remoteWriteCfg)
+}
+
+func newRuler(sharedDir string, name string, ruleSubDir string, amCfg []alert.AlertmanagerConfig, queryCfg []query.Config, remoteWriteCfg *remotewrite.Config) (*Service, error) {
 	dir := filepath.Join(sharedDir, "data", "rule", name)
 	container := filepath.Join(e2e.ContainerSharedDir, "data", "rule", name)
 	if err := os.MkdirAll(dir, 0750); err != nil {
@@ -378,12 +382,11 @@ func NewRuler(sharedDir string, name string, ruleSubDir string, amCfg []alert.Al
 		"--query.sd-dns-interval":         "1s",
 		"--resend-delay":                  "5s",
 	}
-	if remoteWrite {
+	if remoteWriteCfg != nil {
 		rwCfgBytes, err := yaml.Marshal(remoteWriteCfg)
 		if err != nil {
 			return nil, errors.Wrapf(err, "generate remote write config: %v", remoteWriteCfg)
 		}
-		ruleArgs["--remote-write"] = ""
 		ruleArgs["--remote-write.config"] = string(rwCfgBytes)
 	}
 

test/e2e/rule_test.go

@@ -18,7 +18,7 @@ import (
 	"testing"
 	"time"
 
-	commoncfg "github.com/prometheus/common/config"
+	common_cfg "github.com/prometheus/common/config"
 	"github.com/prometheus/prometheus/config"
 	"github.com/thanos-io/thanos/pkg/rules/remotewrite"
 
@@ -600,7 +600,7 @@ groups:
 	testutil.Ok(t, err)
 	testutil.Ok(t, s.StartAndWaitReady(querier))
 
-	r, err := e2ethanos.NewRuler(s.SharedDir(), "1", rulesSubDir, []alert.AlertmanagerConfig{
+	r, err := e2ethanos.NewStatelessRuler(s.SharedDir(), "1", rulesSubDir, []alert.AlertmanagerConfig{
 		{
 			EndpointsConfig: http_util.EndpointsConfig{
 				StaticAddresses: []string{
@@ -620,47 +620,16 @@ groups:
 				Scheme: "http",
 			},
 		},
-	}, true, remotewrite.Config{
+	}, &remotewrite.Config{
 		Name: "ruler-rw-receivers",
 		RemoteStore: &config.RemoteWriteConfig{
-			URL:  &commoncfg.URL{URL: rwURL},
+			URL:  &common_cfg.URL{URL: rwURL},
 			Name: "thanos-receiver",
 		},
 	})
 	testutil.Ok(t, err)
 	testutil.Ok(t, s.StartAndWaitReady(r))
 
-	t.Run("inject samples into receiver to reset its StoreAPI MinTime", func(t *testing.T) {
-		// inject data into receiver to reset its minTime (so it doesn't get filtered out by store)
-		// the sample is injected through a prometheus instance that remote_writes samples into the receiver node
-		prom, _, err := e2ethanos.NewPrometheus(s.SharedDir(), "1", defaultPromConfig("prom", 0, e2ethanos.RemoteWriteEndpoint(receiver.NetworkEndpoint(8081)), ""), e2ethanos.DefaultPrometheusImage())
-		testutil.Ok(t, err)
-		testutil.Ok(t, s.StartAndWaitReady(prom))
-
-		queryAndAssertSeries(t, ctx, querier.HTTPEndpoint(), queryUpWithoutInstance, promclient.QueryOptions{
-			Deduplicate: false,
-		}, []model.Metric{
-			{
-				"job":        "myself",
-				"prometheus": "prom",
-				"receive":    "1",
-				"replica":    "0",
-				"tenant_id":  "default-tenant",
-			},
-		})
-	})
-
-	t.Run("query can contact from receiver", func(t *testing.T) {
-		testAbsentQuery := "absent(nonexistent{job='thanos-receive'})"
-		queryAndAssertSeries(t, ctx, querier.HTTPEndpoint(), testAbsentQuery, promclient.QueryOptions{
-			Deduplicate: false,
-		}, []model.Metric{
-			{
-				"job": "thanos-receive",
-			},
-		})
-	})
-
 	t.Run("can fetch remote-written samples from receiver", func(t *testing.T) {
 		testRecordedSamples := "test_absent_metric"
 		queryAndAssertSeries(t, ctx, querier.HTTPEndpoint(), testRecordedSamples, promclient.QueryOptions{

test/e2e/rules_api_test.go

@@ -96,9 +96,9 @@ func TestRulesAPI_Fanout(t *testing.T) {
 	}
 
 	// Recreate rulers with the corresponding query config.
-	r1, err = e2ethanos.NewRuler(s.SharedDir(), "rule1", thanosRulesSubDir, nil, queryCfg)
+	r1, err = e2ethanos.NewTSDBRuler(s.SharedDir(), "rule1", thanosRulesSubDir, nil, queryCfg)
 	testutil.Ok(t, err)
-	r2, err = e2ethanos.NewRuler(s.SharedDir(), "rule2", thanosRulesSubDir, nil, queryCfg)
+	r2, err = e2ethanos.NewTSDBRuler(s.SharedDir(), "rule2", thanosRulesSubDir, nil, queryCfg)
 	testutil.Ok(t, err)
 	testutil.Ok(t, s.StartAndWaitReady(r1, r2))