From 9dbb6dd8790cca18a86e9031e4d576ba7ab1da39 Mon Sep 17 00:00:00 2001
From: Bence Csati <bence.csati@axoflow.com>
Date: Wed, 4 Dec 2024 12:41:36 +0100
Subject: [PATCH] fix: add flag to skip fail if the endpoint is not available

Signed-off-by: Bence Csati <bence.csati@axoflow.com>
---
 config.go      | 11 +++++++++--
 config_test.go | 11 +++++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/config.go b/config.go
index 723854b..6298a0f 100644
--- a/config.go
+++ b/config.go
@@ -33,6 +33,10 @@ type TCPClientSettings struct {
 type Config struct {
 	TCPClientSettings `mapstructure:",squash"` // squash ensures fields are correctly decoded in embedded struct.
 
+	// SkipFailOnInvalidTCPEndpoint controls whether to fail if the endpoint is invalid.
+	// This is useful for cases where the collector is started before the endpoint becomes available.
+	SkipFailOnInvalidTCPEndpoint bool `mapstructure:"skip_fail_on_invalid_tcp_endpoint"`
+
 	// RequireAck enables the acknowledgement feature.
 	RequireAck bool `mapstructure:"require_ack"`
 
@@ -87,8 +91,11 @@ func (config *Config) Validate() error {
 
 	// Resolve TCP address just to ensure that it is a valid one. It is better
 	// to fail here than at when the exporter is started.
-	if _, err := net.ResolveTCPAddr("tcp", config.Endpoint); err != nil {
-		return fmt.Errorf("exporter has an invalid TCP endpoint: %w", err)
+	if !config.SkipFailOnInvalidTCPEndpoint {
+		if _, err := net.ResolveTCPAddr("tcp", config.Endpoint); err != nil {
+			return fmt.Errorf("exporter has an invalid TCP endpoint: %w", err)
+		}
 	}
+
 	return nil
 }
diff --git a/config_test.go b/config_test.go
index 8b47641..91360c8 100644
--- a/config_test.go
+++ b/config_test.go
@@ -110,6 +110,17 @@ func TestConfigValidate(t *testing.T) {
 			},
 			err: fmt.Errorf("exporter has an invalid TCP endpoint: address http://localhost:24224: too many colons in address"),
 		},
+		{
+			desc: "Endpoint is invalid but SkipFailOnInvalidTCPEndpoint is false",
+			cfg: &Config{
+				TCPClientSettings: TCPClientSettings{
+					Endpoint:          "http://localhost:24224",
+					ConnectionTimeout: time.Second * 30,
+				},
+				SkipFailOnInvalidTCPEndpoint: true,
+			},
+			err: nil,
+		},
 		{
 			desc: "Config is valid",
 			cfg: &Config{