support core service validate command

internal/settings/settings.go

@@ -304,7 +304,8 @@ func parseArgs(args []string) (*Settings, error) {
 	settings.setProperties, settings.discoveryProperties = parseSetOptionArguments(settings.setOptionArguments.value)
 
 	// Pass flags that are handled by the collector core service as raw command line arguments.
-	settings.colCoreArgs = flagSetToArgs(colCoreFlags, flagSet)
+	colCoreCommands := []string{"validate"}
+	settings.colCoreArgs = flagSetToArgs(colCoreFlags, colCoreCommands, flagSet)
 
 	return settings, nil
 }
@@ -320,12 +321,12 @@ func parseSetOptionArguments(arguments []string) (setProperties, discoveryProper
 	return
 }
 
-// flagSetToArgs takes a list of flag names and returns a list of corresponding command line arguments
-// using values from the provided flagSet.
+// flagSetToArgs takes slices of core service flag names and arguments and returns a slice of corresponding command line
+// arguments using values suitable for being passed to the underlying collector service.
 // The flagSet must be populated (flagSet.Parse is called), otherwise the returned list of arguments will be empty.
-func flagSetToArgs(flagNames []string, flagSet *flag.FlagSet) []string {
+func flagSetToArgs(colFlagNames, colCommands []string, flagSet *flag.FlagSet) []string {
 	var out []string
-	for _, flagName := range flagNames {
+	for _, flagName := range colFlagNames {
 		flag := flagSet.Lookup(flagName)
 		if flag.Changed {
 			switch fv := flag.Value.(type) {
@@ -338,6 +339,16 @@ func flagSetToArgs(flagNames []string, flagSet *flag.FlagSet) []string {
 			}
 		}
 	}
+
+	allowed := map[string]struct{}{}
+	for _, cmd := range colCommands {
+		allowed[cmd] = struct{}{}
+	}
+	for _, arg := range flagSet.Args() {
+		if _, ok := allowed[arg]; ok {
+			out = append(out, arg)
+		}
+	}
 	return out
 }
 

internal/settings/settings_test.go

@@ -203,6 +203,14 @@ func TestSplunkConfigYamlNotUtilizedInResolverURIsWithConfigEnvVar(t *testing.T)
 	require.Equal(t, []string{localGatewayConfig}, settings.ResolverURIs())
 }
 
+func TestNewSettingsWithValidate(t *testing.T) {
+	t.Cleanup(setRequiredEnvVars(t))
+	settings, err := New([]string{"validate"})
+	require.NoError(t, err)
+	require.NotNil(t, settings)
+	require.Equal(t, []string{"--feature-gates", "-telemetry.useOtelForInternalMetrics", "validate"}, settings.ColCoreArgs())
+}
+
 func TestCheckRuntimeParams_Default(t *testing.T) {
 	t.Cleanup(setRequiredEnvVars(t))
 	require.NoError(t, os.Setenv(ConfigEnvVar, localGatewayConfig))

tests/general/validate_test.go

@@ -0,0 +1,157 @@
+// Copyright Splunk, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build integration
+
+package tests
+
+import (
+	"fmt"
+	"regexp"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/signalfx/splunk-otel-collector/tests/testutils"
+)
+
+func TestCoreValidateDefaultConfig(t *testing.T) {
+	tc := testutils.NewTestcase(t)
+	defer tc.PrintLogsOnFailure()
+	defer tc.ShutdownOTLPReceiverSink()
+
+	c, shutdown := tc.SplunkOtelCollectorContainer(
+		"", func(collector testutils.Collector) testutils.Collector {
+			// deferring running service for exec
+			c := collector.WithEnv(
+				map[string]string{
+					"SPLUNK_REALM":        "noop",
+					"SPLUNK_ACCESS_TOKEN": "noop",
+				},
+			).WithArgs("-c", "trap exit SIGTERM ; echo ok ; while true; do : ; done")
+			cc := c.(*testutils.CollectorContainer)
+			cc.Container = cc.Container.WithEntrypoint("bash").WillWaitForLogs("ok")
+			return cc
+		},
+	)
+
+	defer shutdown()
+
+	for _, config := range []string{"gateway", "agent"} {
+		config := config
+		t.Run(config, func(t *testing.T) {
+			sc, stdout, stderr := c.Container.AssertExec(t, 15*time.Second,
+				"bash", "-c", fmt.Sprintf("/otelcol --config /etc/otel/collector/%s_config.yaml validate", config),
+			)
+			assert.Zero(t, sc)
+			require.Empty(t, stdout)
+			require.False(t, regexp.MustCompile("(?i)error").MatchString(stderr))
+		})
+	}
+}
+
+func TestCoreValidateYamlProvider(t *testing.T) {
+	tc := testutils.NewTestcase(t)
+	defer tc.PrintLogsOnFailure()
+	defer tc.ShutdownOTLPReceiverSink()
+
+	config := `exporters:
+  debug:
+    verbosity: detailed
+receivers:
+  hostmetrics:
+    collection_interval: 10s
+    scrapers:
+      cpu:
+service:
+  pipelines:
+    metrics:
+      exporters:
+      - debug
+      receivers:
+      - hostmetrics
+`
+
+	c, shutdown := tc.SplunkOtelCollectorContainer(
+		"", func(collector testutils.Collector) testutils.Collector {
+			// deferring running service for exec
+			c := collector.WithEnv(
+				map[string]string{
+					"SPLUNK_CONFIG":      "",
+					"SPLUNK_CONFIG_YAML": config,
+				},
+			).WithArgs("-c", "trap exit SIGTERM ; echo ok ; while true; do : ; done")
+			cc := c.(*testutils.CollectorContainer)
+			cc.Container = cc.Container.WithEntrypoint("bash").WillWaitForLogs("ok")
+			return cc
+		},
+	)
+
+	defer shutdown()
+
+	sc, stdout, stderr := c.Container.AssertExec(t, 15*time.Second,
+		"bash", "-c", "/otelcol validate",
+	)
+	assert.Zero(t, sc)
+	require.Empty(t, stdout)
+	require.False(t, regexp.MustCompile("(?i)error").MatchString(stderr))
+}
+
+func TestCoreValidateDetectsInvalidYamlProvider(t *testing.T) {
+	tc := testutils.NewTestcase(t)
+	defer tc.PrintLogsOnFailure()
+	defer tc.ShutdownOTLPReceiverSink()
+
+	config := `exporters:
+  not-real:
+    endpoint: an-endpoint
+receivers:
+  hostmetrics:
+    collection_interval: 10s
+    scrapers:
+service:
+  pipelines:
+    metrics:
+      exporters:
+      - not-real
+      receivers:
+      - hostmetrics
+`
+
+	c, shutdown := tc.SplunkOtelCollectorContainer(
+		"", func(collector testutils.Collector) testutils.Collector {
+			// deferring running service for exec
+			c := collector.WithEnv(
+				map[string]string{
+					"SPLUNK_CONFIG":      "",
+					"SPLUNK_CONFIG_YAML": config,
+				},
+			).WithArgs("-c", "trap exit SIGTERM ; echo ok ; while true; do : ; done")
+			cc := c.(*testutils.CollectorContainer)
+			cc.Container = cc.Container.WithEntrypoint("bash").WillWaitForLogs("ok")
+			return cc
+		},
+	)
+
+	defer shutdown()
+
+	sc, stdout, stderr := c.Container.AssertExec(t, 15*time.Second,
+		"bash", "-c", "/otelcol validate",
+	)
+	require.Equal(t, 1, sc)
+	require.Empty(t, stdout)
+	require.Contains(t, stderr, `error decoding 'exporters': unknown type: "not-real"`)
+}