From 9404e2f30ae5ab9ede8f53530f600d5cc440de8e Mon Sep 17 00:00:00 2001
From: Erik Baranowski <39704712+erikbaranowski@users.noreply.github.com>
Date: Fri, 29 Sep 2023 10:05:25 -0400
Subject: [PATCH] wire up scrape_classic_histogram for the prometheus converter
 (#5336)

* wire up scrape_classic_histogram for the prometheus converter

Signed-off-by: erikbaranowski <39704712+erikbaranowski@users.noreply.github.com>

---------

Signed-off-by: erikbaranowski <39704712+erikbaranowski@users.noreply.github.com>
---
 .../internal/prometheusconvert/scrape.go      | 44 +++++++++----------
 .../testdata/unsupported.diags                |  1 -
 .../testdata/unsupported.river                |  5 ++-
 3 files changed, 24 insertions(+), 26 deletions(-)

diff --git a/converter/internal/prometheusconvert/scrape.go b/converter/internal/prometheusconvert/scrape.go
index 120ebf8cd9fd..533c86458f4d 100644
--- a/converter/internal/prometheusconvert/scrape.go
+++ b/converter/internal/prometheusconvert/scrape.go
@@ -28,10 +28,6 @@ func appendPrometheusScrape(pb *prometheusBlocks, scrapeConfig *prom_config.Scra
 func validatePrometheusScrape(scrapeConfig *prom_config.ScrapeConfig) diag.Diagnostics {
 	var diags diag.Diagnostics
 
-	if scrapeConfig.ScrapeClassicHistograms {
-		diags.Add(diag.SeverityLevelError, "unsupported scrape_classic_histograms for scrape_configs")
-	}
-
 	if scrapeConfig.NativeHistogramBucketLimit != 0 {
 		diags.Add(diag.SeverityLevelError, "unsupported native_histogram_bucket_limit for scrape_configs")
 	}
@@ -47,25 +43,27 @@ func toScrapeArguments(scrapeConfig *prom_config.ScrapeConfig, forwardTo []stora
 	}
 
 	return &scrape.Arguments{
-		Targets:               targets,
-		ForwardTo:             forwardTo,
-		JobName:               scrapeConfig.JobName,
-		HonorLabels:           scrapeConfig.HonorLabels,
-		HonorTimestamps:       scrapeConfig.HonorTimestamps,
-		Params:                scrapeConfig.Params,
-		ScrapeInterval:        time.Duration(scrapeConfig.ScrapeInterval),
-		ScrapeTimeout:         time.Duration(scrapeConfig.ScrapeTimeout),
-		MetricsPath:           scrapeConfig.MetricsPath,
-		Scheme:                scrapeConfig.Scheme,
-		BodySizeLimit:         scrapeConfig.BodySizeLimit,
-		SampleLimit:           scrapeConfig.SampleLimit,
-		TargetLimit:           scrapeConfig.TargetLimit,
-		LabelLimit:            scrapeConfig.LabelLimit,
-		LabelNameLengthLimit:  scrapeConfig.LabelNameLengthLimit,
-		LabelValueLengthLimit: scrapeConfig.LabelValueLengthLimit,
-		HTTPClientConfig:      *ToHttpClientConfig(&scrapeConfig.HTTPClientConfig),
-		ExtraMetrics:          false,
-		Clustering:            scrape.Clustering{Enabled: false},
+		Targets:                   targets,
+		ForwardTo:                 forwardTo,
+		JobName:                   scrapeConfig.JobName,
+		HonorLabels:               scrapeConfig.HonorLabels,
+		HonorTimestamps:           scrapeConfig.HonorTimestamps,
+		Params:                    scrapeConfig.Params,
+		ScrapeClassicHistograms:   scrapeConfig.ScrapeClassicHistograms,
+		ScrapeInterval:            time.Duration(scrapeConfig.ScrapeInterval),
+		ScrapeTimeout:             time.Duration(scrapeConfig.ScrapeTimeout),
+		MetricsPath:               scrapeConfig.MetricsPath,
+		Scheme:                    scrapeConfig.Scheme,
+		BodySizeLimit:             scrapeConfig.BodySizeLimit,
+		SampleLimit:               scrapeConfig.SampleLimit,
+		TargetLimit:               scrapeConfig.TargetLimit,
+		LabelLimit:                scrapeConfig.LabelLimit,
+		LabelNameLengthLimit:      scrapeConfig.LabelNameLengthLimit,
+		LabelValueLengthLimit:     scrapeConfig.LabelValueLengthLimit,
+		HTTPClientConfig:          *ToHttpClientConfig(&scrapeConfig.HTTPClientConfig),
+		ExtraMetrics:              false,
+		EnableProtobufNegotiation: false,
+		Clustering:                scrape.Clustering{Enabled: false},
 	}
 }
 
diff --git a/converter/internal/prometheusconvert/testdata/unsupported.diags b/converter/internal/prometheusconvert/testdata/unsupported.diags
index 83757cd5c64f..3efc82ee60ab 100644
--- a/converter/internal/prometheusconvert/testdata/unsupported.diags
+++ b/converter/internal/prometheusconvert/testdata/unsupported.diags
@@ -4,7 +4,6 @@
 (Error) unsupported rule_files config was provided
 (Error) unsupported HTTP Client config no_proxy was provided
 (Error) unsupported service discovery nomad was provided
-(Error) unsupported scrape_classic_histograms for scrape_configs
 (Error) unsupported native_histogram_bucket_limit for scrape_configs
 (Error) unsupported storage config was provided
 (Error) unsupported tracing config was provided
diff --git a/converter/internal/prometheusconvert/testdata/unsupported.river b/converter/internal/prometheusconvert/testdata/unsupported.river
index 5c0f43c0ba65..e275ee15edb3 100644
--- a/converter/internal/prometheusconvert/testdata/unsupported.river
+++ b/converter/internal/prometheusconvert/testdata/unsupported.river
@@ -19,8 +19,9 @@ prometheus.scrape "prometheus2" {
 	targets = [{
 		__address__ = "localhost:9091",
 	}]
-	forward_to = [prometheus.remote_write.default.receiver]
-	job_name   = "prometheus2"
+	forward_to               = [prometheus.remote_write.default.receiver]
+	job_name                 = "prometheus2"
+	scrape_classic_histogram = true
 }
 
 prometheus.remote_write "default" {