From d5b6af5167a2791b3e14f7c0c9d50a9d00ec9e0a Mon Sep 17 00:00:00 2001
From: Matt Cotter <matthew.cotter@observeinc.com>
Date: Thu, 24 Oct 2024 15:36:29 -0500
Subject: [PATCH 1/2] feat: validate the otel configuration in diagnose

---
 internal/commands/diagnose/diagnose.go        |  1 +
 internal/commands/diagnose/otelconfigcheck.go | 56 +++++++++++++++++++
 .../commands/diagnose/otelconfigcheck.tmpl    |  5 ++
 3 files changed, 62 insertions(+)
 create mode 100644 internal/commands/diagnose/otelconfigcheck.go
 create mode 100644 internal/commands/diagnose/otelconfigcheck.tmpl

diff --git a/internal/commands/diagnose/diagnose.go b/internal/commands/diagnose/diagnose.go
index 2e7a36825..16d65ae19 100644
--- a/internal/commands/diagnose/diagnose.go
+++ b/internal/commands/diagnose/diagnose.go
@@ -23,6 +23,7 @@ type Diagnostic struct {
 
 var diagnostics = []Diagnostic{
 	configDiagnostic(),
+	otelconfigDiagnostic(),
 	authDiagnostic(),
 }
 
diff --git a/internal/commands/diagnose/otelconfigcheck.go b/internal/commands/diagnose/otelconfigcheck.go
new file mode 100644
index 000000000..1a214a4d5
--- /dev/null
+++ b/internal/commands/diagnose/otelconfigcheck.go
@@ -0,0 +1,56 @@
+package diagnose
+
+import (
+	"context"
+	"embed"
+
+	"github.com/observeinc/observe-agent/internal/commands/start"
+	"github.com/spf13/viper"
+	"go.opentelemetry.io/collector/otelcol"
+)
+
+type OtelConfigTestResult struct {
+	Passed bool
+	Error  string
+}
+
+func checkOtelConfig(_ *viper.Viper) (any, error) {
+	colSettings, cleanup, err := start.SetupAndGenerateCollectorSettings()
+	if err != nil {
+		return nil, err
+	}
+	if cleanup != nil {
+		defer cleanup()
+	}
+	// Copying the implementation from the `otelcol validate` command
+	col, err := otelcol.NewCollector(*colSettings)
+	if err != nil {
+		return nil, err
+	}
+	err = col.DryRun(context.Background())
+	if err != nil {
+		return OtelConfigTestResult{
+			Passed: false,
+			Error:  err.Error(),
+		}, nil
+	}
+	return OtelConfigTestResult{
+		Passed: true,
+	}, nil
+}
+
+const otelconfigcheckTemplate = "otelconfigcheck.tmpl"
+
+var (
+	//go:embed otelconfigcheck.tmpl
+	otelconfigcheckTemplateFS embed.FS
+)
+
+func otelconfigDiagnostic() Diagnostic {
+	return Diagnostic{
+		check:        checkOtelConfig,
+		checkName:    "OTEL Config Check",
+		templateName: otelconfigcheckTemplate,
+		templateFS:   otelconfigcheckTemplateFS,
+	}
+}
diff --git a/internal/commands/diagnose/otelconfigcheck.tmpl b/internal/commands/diagnose/otelconfigcheck.tmpl
new file mode 100644
index 000000000..dbe90e51d
--- /dev/null
+++ b/internal/commands/diagnose/otelconfigcheck.tmpl
@@ -0,0 +1,5 @@
+{{- if .Passed }}
+OTEL configuration is valid.
+{{- else }}
+⚠️ OTEL configuration validation failed with error {{ .Error }}
+{{- end }}

From a1532ba77418210e98a258b930944dc48e7db612 Mon Sep 17 00:00:00 2001
From: Matt Cotter <matthew.cotter@observeinc.com>
Date: Mon, 28 Oct 2024 15:00:43 -0500
Subject: [PATCH 2/2] link to the otel validate command

---
 internal/commands/diagnose/otelconfigcheck.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/internal/commands/diagnose/otelconfigcheck.go b/internal/commands/diagnose/otelconfigcheck.go
index 1a214a4d5..5a33976b5 100644
--- a/internal/commands/diagnose/otelconfigcheck.go
+++ b/internal/commands/diagnose/otelconfigcheck.go
@@ -22,7 +22,8 @@ func checkOtelConfig(_ *viper.Viper) (any, error) {
 	if cleanup != nil {
 		defer cleanup()
 	}
-	// Copying the implementation from the `otelcol validate` command
+	// These are the same checks as the `otelcol validate` command:
+	// https://github.com/open-telemetry/opentelemetry-collector/blob/main/otelcol/command_validate.go
 	col, err := otelcol.NewCollector(*colSettings)
 	if err != nil {
 		return nil, err