Merge pull request #14747 from prometheus/arthursens/agentmode-flag

Promote Agent mode to it's own cmdline flag

cmd/prometheus/main.go

@@ -198,9 +198,6 @@ func (c *flagConfig) setFeatureListOptions(logger log.Logger) error {
 			case "new-service-discovery-manager":
 				c.enableNewSDManager = true
 				level.Info(logger).Log("msg", "Experimental service discovery manager")
-			case "agent":
-				agentMode = true
-				level.Info(logger).Log("msg", "Experimental agent mode enabled.")
 			case "promql-per-step-stats":
 				c.enablePerStepStats = true
 				level.Info(logger).Log("msg", "Experimental per-step statistics reporting")
@@ -461,9 +458,11 @@ func main() {
 	a.Flag("scrape.discovery-reload-interval", "Interval used by scrape manager to throttle target groups updates.").
 		Hidden().Default("5s").SetValue(&cfg.scrape.DiscoveryReloadInterval)
 
-	a.Flag("enable-feature", "Comma separated feature names to enable. Valid options: agent, auto-gomemlimit, exemplar-storage, expand-external-labels, memory-snapshot-on-shutdown, promql-per-step-stats, promql-experimental-functions, extra-scrape-metrics, new-service-discovery-manager, auto-gomaxprocs, no-default-scrape-port, native-histograms, otlp-write-receiver, created-timestamp-zero-ingestion, concurrent-rule-eval. See https://prometheus.io/docs/prometheus/latest/feature_flags/ for more details.").
+	a.Flag("enable-feature", "Comma separated feature names to enable. Valid options: auto-gomemlimit, exemplar-storage, expand-external-labels, memory-snapshot-on-shutdown, promql-per-step-stats, promql-experimental-functions, extra-scrape-metrics, new-service-discovery-manager, auto-gomaxprocs, no-default-scrape-port, native-histograms, otlp-write-receiver, created-timestamp-zero-ingestion, concurrent-rule-eval. See https://prometheus.io/docs/prometheus/latest/feature_flags/ for more details.").
 		Default("").StringsVar(&cfg.featureList)
 
+	a.Flag("agent", "Run Prometheus in 'Agent mode'.").BoolVar(&agentMode)
+
 	promlogflag.AddFlags(a, &cfg.promlogConfig)
 
 	a.Flag("write-documentation", "Generate command line documentation. Internal use.").Hidden().Action(func(ctx *kingpin.ParseContext) error {

cmd/prometheus/main_test.go

@@ -348,7 +348,7 @@ func getCurrentGaugeValuesFor(t *testing.T, reg prometheus.Gatherer, metricNames
 }
 
 func TestAgentSuccessfulStartup(t *testing.T) {
-	prom := exec.Command(promPath, "-test.main", "--enable-feature=agent", "--web.listen-address=0.0.0.0:0", "--config.file="+agentConfig)
+	prom := exec.Command(promPath, "-test.main", "--agent", "--web.listen-address=0.0.0.0:0", "--config.file="+agentConfig)
 	require.NoError(t, prom.Start())
 
 	actualExitStatus := 0
@@ -366,7 +366,7 @@ func TestAgentSuccessfulStartup(t *testing.T) {
 }
 
 func TestAgentFailedStartupWithServerFlag(t *testing.T) {
-	prom := exec.Command(promPath, "-test.main", "--enable-feature=agent", "--storage.tsdb.path=.", "--web.listen-address=0.0.0.0:0", "--config.file="+promConfig)
+	prom := exec.Command(promPath, "-test.main", "--agent", "--storage.tsdb.path=.", "--web.listen-address=0.0.0.0:0", "--config.file="+promConfig)
 
 	output := bytes.Buffer{}
 	prom.Stderr = &output
@@ -393,7 +393,7 @@ func TestAgentFailedStartupWithServerFlag(t *testing.T) {
 }
 
 func TestAgentFailedStartupWithInvalidConfig(t *testing.T) {
-	prom := exec.Command(promPath, "-test.main", "--enable-feature=agent", "--web.listen-address=0.0.0.0:0", "--config.file="+promConfig)
+	prom := exec.Command(promPath, "-test.main", "--agent", "--web.listen-address=0.0.0.0:0", "--config.file="+promConfig)
 	require.NoError(t, prom.Start())
 
 	actualExitStatus := 0
@@ -431,7 +431,7 @@ func TestModeSpecificFlags(t *testing.T) {
 			args := []string{"-test.main", tc.arg, t.TempDir(), "--web.listen-address=0.0.0.0:0"}
 
 			if tc.mode == "agent" {
-				args = append(args, "--enable-feature=agent", "--config.file="+agentConfig)
+				args = append(args, "--agent", "--config.file="+agentConfig)
 			} else {
 				args = append(args, "--config.file="+promConfig)
 			}

docs/command-line/prometheus.md

@@ -55,7 +55,8 @@ The Prometheus monitoring server
 | <code class="text-nowrap">--query.timeout</code> | Maximum time a query may take before being aborted. Use with server mode only. | `2m` |
 | <code class="text-nowrap">--query.max-concurrency</code> | Maximum number of queries executed concurrently. Use with server mode only. | `20` |
 | <code class="text-nowrap">--query.max-samples</code> | Maximum number of samples a single query can load into memory. Note that queries will fail if they try to load more samples than this into memory, so this also limits the number of samples a query can return. Use with server mode only. | `50000000` |
-| <code class="text-nowrap">--enable-feature</code> | Comma separated feature names to enable. Valid options: agent, auto-gomemlimit, exemplar-storage, expand-external-labels, memory-snapshot-on-shutdown, promql-per-step-stats, promql-experimental-functions, extra-scrape-metrics, new-service-discovery-manager, auto-gomaxprocs, no-default-scrape-port, native-histograms, otlp-write-receiver, created-timestamp-zero-ingestion, concurrent-rule-eval. See https://prometheus.io/docs/prometheus/latest/feature_flags/ for more details. |  |
+| <code class="text-nowrap">--enable-feature</code> | Comma separated feature names to enable. Valid options: auto-gomemlimit, exemplar-storage, expand-external-labels, memory-snapshot-on-shutdown, promql-per-step-stats, promql-experimental-functions, extra-scrape-metrics, new-service-discovery-manager, auto-gomaxprocs, no-default-scrape-port, native-histograms, otlp-write-receiver, created-timestamp-zero-ingestion, concurrent-rule-eval. See https://prometheus.io/docs/prometheus/latest/feature_flags/ for more details. |  |
+| <code class="text-nowrap">--agent</code> | Run Prometheus in 'Agent mode'. |  |
 | <code class="text-nowrap">--log.level</code> | Only log messages with the given severity or above. One of: [debug, info, warn, error] | `info` |
 | <code class="text-nowrap">--log.format</code> | Output format of log messages. One of: [logfmt, json] | `logfmt` |