From c58709a9625b361200183e3dff083a25e4e8ef3b Mon Sep 17 00:00:00 2001
From: Paschalis Tsilias <tpaschalis@users.noreply.github.com>
Date: Thu, 22 Feb 2024 18:47:38 +0200
Subject: [PATCH] otelcolconvert: support converting probabilistic_sampler
 processor (#6481)

Signed-off-by: Paschalis Tsilias <paschalist0@gmail.com>
---
 ...converter_probabilisticsamplerprocessor.go | 62 +++++++++++++++++++
 .../testdata/probabilistic_sampler.river      | 24 +++++++
 .../testdata/probabilistic_sampler.yaml       | 32 ++++++++++
 3 files changed, 118 insertions(+)
 create mode 100644 converter/internal/otelcolconvert/converter_probabilisticsamplerprocessor.go
 create mode 100644 converter/internal/otelcolconvert/testdata/probabilistic_sampler.river
 create mode 100644 converter/internal/otelcolconvert/testdata/probabilistic_sampler.yaml

diff --git a/converter/internal/otelcolconvert/converter_probabilisticsamplerprocessor.go b/converter/internal/otelcolconvert/converter_probabilisticsamplerprocessor.go
new file mode 100644
index 000000000000..32a81192a3f1
--- /dev/null
+++ b/converter/internal/otelcolconvert/converter_probabilisticsamplerprocessor.go
@@ -0,0 +1,62 @@
+package otelcolconvert
+
+import (
+	"fmt"
+
+	"github.com/grafana/agent/component/otelcol"
+	"github.com/grafana/agent/component/otelcol/processor/probabilistic_sampler"
+	"github.com/grafana/agent/converter/diag"
+	"github.com/grafana/agent/converter/internal/common"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/probabilisticsamplerprocessor"
+	"go.opentelemetry.io/collector/component"
+)
+
+func init() {
+	converters = append(converters, probabilisticSamplerProcessorConverter{})
+}
+
+type probabilisticSamplerProcessorConverter struct{}
+
+func (probabilisticSamplerProcessorConverter) Factory() component.Factory {
+	return probabilisticsamplerprocessor.NewFactory()
+}
+
+func (probabilisticSamplerProcessorConverter) InputComponentName() string {
+	return "otelcol.processor.probabilistic_sampler"
+}
+
+func (probabilisticSamplerProcessorConverter) ConvertAndAppend(state *state, id component.InstanceID, cfg component.Config) diag.Diagnostics {
+	var diags diag.Diagnostics
+
+	label := state.FlowComponentLabel()
+
+	args := toProbabilisticSamplerProcessor(state, id, cfg.(*probabilisticsamplerprocessor.Config))
+	block := common.NewBlockWithOverride([]string{"otelcol", "processor", "probabilistic_sampler"}, label, args)
+
+	diags.Add(
+		diag.SeverityLevelInfo,
+		fmt.Sprintf("Converted %s into %s", stringifyInstanceID(id), stringifyBlock(block)),
+	)
+
+	state.Body().AppendBlock(block)
+	return diags
+}
+
+func toProbabilisticSamplerProcessor(state *state, id component.InstanceID, cfg *probabilisticsamplerprocessor.Config) *probabilistic_sampler.Arguments {
+	var (
+		nextTraces = state.Next(id, component.DataTypeTraces)
+		nextLogs   = state.Next(id, component.DataTypeLogs)
+	)
+
+	return &probabilistic_sampler.Arguments{
+		SamplingPercentage: cfg.SamplingPercentage,
+		HashSeed:           cfg.HashSeed,
+		AttributeSource:    string(cfg.AttributeSource),
+		FromAttribute:      cfg.FromAttribute,
+		SamplingPriority:   cfg.SamplingPriority,
+		Output: &otelcol.ConsumerArguments{
+			Logs:   toTokenizedConsumers(nextLogs),
+			Traces: toTokenizedConsumers(nextTraces),
+		},
+	}
+}
diff --git a/converter/internal/otelcolconvert/testdata/probabilistic_sampler.river b/converter/internal/otelcolconvert/testdata/probabilistic_sampler.river
new file mode 100644
index 000000000000..b911192ed55b
--- /dev/null
+++ b/converter/internal/otelcolconvert/testdata/probabilistic_sampler.river
@@ -0,0 +1,24 @@
+otelcol.receiver.otlp "default" {
+	grpc { }
+
+	http { }
+
+	output {
+		metrics = [otelcol.exporter.otlp.default.input]
+		logs    = [otelcol.processor.probabilistic_sampler.default.input]
+		traces  = [otelcol.processor.probabilistic_sampler.default.input]
+	}
+}
+
+otelcol.processor.probabilistic_sampler "default" {
+	output {
+		logs   = [otelcol.exporter.otlp.default.input]
+		traces = [otelcol.exporter.otlp.default.input]
+	}
+}
+
+otelcol.exporter.otlp "default" {
+	client {
+		endpoint = "database:4317"
+	}
+}
diff --git a/converter/internal/otelcolconvert/testdata/probabilistic_sampler.yaml b/converter/internal/otelcolconvert/testdata/probabilistic_sampler.yaml
new file mode 100644
index 000000000000..6f058dbd6c62
--- /dev/null
+++ b/converter/internal/otelcolconvert/testdata/probabilistic_sampler.yaml
@@ -0,0 +1,32 @@
+receivers:
+  otlp:
+    protocols:
+      grpc:
+      http:
+
+exporters:
+  otlp:
+    # Our defaults have drifted from upstream, so we explicitly set our
+    # defaults below (balancer_name and queue_size).
+    endpoint: database:4317
+    balancer_name: pick_first
+    sending_queue:
+      queue_size: 5000
+
+processors:
+  probabilistic_sampler:
+
+service:
+  pipelines:
+    metrics:
+      receivers: [otlp]
+      processors: []
+      exporters: [otlp]
+    logs:
+      receivers: [otlp]
+      processors: [probabilistic_sampler]
+      exporters: [otlp]
+    traces:
+      receivers: [otlp]
+      processors: [probabilistic_sampler]
+      exporters: [otlp]