Make perf testbed OS agnostic (#55) (#64)

Leveraging GOOS to make the tests run seamless in multiple OSes. There will be separate work to establish different baselines for different platforms, this first change is just to make it runs without manual adaptations on multiple OSes.

Author: Paulo Janotti

testbed/testbed/test_bed.go

@@ -25,11 +25,14 @@
 package testbed
 
 import (
+	"bytes"
 	"errors"
 	"log"
 	"os"
 	"path"
 	"path/filepath"
+	"runtime"
+	"text/template"
 
 	"github.com/spf13/viper"
 )
@@ -64,10 +67,28 @@ func LoadConfig() error {
 
 	testBedConfigDir := path.Dir(testBedConfigFile)
 
+	// Use templates to expand some selected content on the config file.
+	cfgTemplate, err := template.ParseFiles(testBedConfigFile)
+	if err != nil {
+		log.Fatalf("Template failed to parse config file %q: %s",
+			testBedConfigFile, err.Error())
+	}
+
+	templateVars := struct {
+		GOOS string
+	}{
+		GOOS: runtime.GOOS,
+	}
+	var buf bytes.Buffer
+	if err := cfgTemplate.Execute(&buf, templateVars); err != nil {
+		log.Fatalf("Configuration template failed to run on file %q: %s",
+			testBedConfigFile, err.Error())
+	}
+
 	// Read the config.
 	v := viper.New()
-	v.SetConfigFile(testBedConfigFile)
-	if err = v.ReadInConfig(); err != nil {
+	v.SetConfigType("yaml")
+	if err = v.ReadConfig(bytes.NewBuffer(buf.Bytes())); err != nil {
 		log.Fatalf("Cannot load test bed config from %q: %s",
 			testBedConfigFile, err.Error())
 	}
@@ -78,7 +99,6 @@ func LoadConfig() error {
 	}
 
 	// Convert relative paths to absolute.
-
 	testBedConfig.Agent, err = filepath.Abs(path.Join(testBedConfigDir, testBedConfig.Agent))
 	if err != nil {
 		log.Fatalf("Cannot resolve file name %q: %s",

testbed/tests/.gitignore

@@ -1 +1 @@
-agent: ../../bin/otelsvc_linux
+agent: ../../bin/otelsvc_{{.GOOS}}