The very basic metricator-client and package.

Package can be used in external things if needed.

cmd/metricator-client/main.go

@@ -0,0 +1,105 @@
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+
+	"go.dev.pztrn.name/metricator/internal/common"
+	"go.dev.pztrn.name/metricator/internal/configuration"
+	"go.dev.pztrn.name/metricator/internal/logger"
+	"go.dev.pztrn.name/metricator/pkg/client"
+)
+
+// nolint:gochecknoglobals
+var (
+	application       = flag.String("application", "", "Application to query.")
+	appsList          = flag.Bool("apps-list", false, "Show application's list registered at Metricator.")
+	metricatorHost    = flag.String("metricator-host", "", "IP address or domain on which Metricator is available")
+	metricatorTimeout = flag.Int("metricator-timeout", 5, "Timeout for requests sent to Metricator.")
+	metricsList       = flag.Bool("metrics-list", false, "Show metrics list. Requires 'application' parameter.")
+	metric            = flag.String("metric", "", "Metric data to retrieve. Requires 'application' parameter.")
+)
+
+func main() {
+	config := configuration.NewConfig()
+
+	// Parse configuration.
+	flag.Parse()
+
+	err := config.Parse()
+	if err != nil {
+		log.Fatalln("Failed to parse configuration:", err.Error())
+	}
+
+	logger := logger.NewLogger(config.Logger)
+
+	logger.Debugf("Starting Metricator client, version %s from branch %s (build #%s, commit hash %s)\n",
+		common.Version,
+		common.Branch,
+		common.Build,
+		common.CommitHash,
+	)
+
+	// Check configuration.
+	// We cannot work at all if host isn't defined.
+	if *metricatorHost == "" {
+		logger.Infoln("Host isn't defined.")
+
+		flag.PrintDefaults()
+		os.Exit(1)
+	}
+
+	// If nothing is requested - show error message.
+	if !*appsList && !*metricsList && *metric == "" {
+		logger.Infoln("No action specified.")
+
+		flag.PrintDefaults()
+		os.Exit(1)
+	}
+
+	// When asking to metrics list we need application to be defined.
+	if *metricsList && *application == "" {
+		logger.Infoln("Getting metrics list requires 'application' parameter to be filled.")
+
+		flag.PrintDefaults()
+		os.Exit(1)
+	}
+
+	// When asking for specific metric we need application to be defined.
+	if *metric != "" && *application == "" {
+		logger.Infoln("Getting metric data requires 'application' parameter to be filled.")
+
+		flag.PrintDefaults()
+		os.Exit(1)
+	}
+
+	clientConfig := &client.Config{
+		Host:    *metricatorHost,
+		Timeout: *metricatorTimeout,
+	}
+
+	c := client.NewClient(clientConfig, logger)
+
+	var data interface{}
+
+	switch {
+	case *appsList:
+		data = c.GetAppsList()
+	case *metricsList:
+		data = c.GetMetricsList(*application)
+	case *metric != "":
+		data = c.GetMetric(*application, *metric)
+	}
+
+	dataAsBytes, err := json.Marshal(data)
+	if err != nil {
+		logger.Infoln("Failed to marshal data from Metricator:", err.Error())
+
+		os.Exit(2)
+	}
+
+	fmt.Println(string(dataAsBytes))
+}