Address linter warnings

src/cmd/config-generator/app/config.go

@@ -36,7 +36,9 @@ func LoadConfig(log *log.Logger) Config {
 		log.Fatal(err)
 	}
 
-	envstruct.WriteReport(&cfg)
+	if err := envstruct.WriteReport(&cfg); err != nil {
+		log.Fatal(err)
+	}
 
 	return cfg
 }

src/cmd/config-generator/app/generator.go

@@ -6,7 +6,7 @@ import (
 	"io/ioutil"
 	"log"
 	"net/http"
-	_ "net/http/pprof"
+	_ "net/http/pprof" // nolint:gosec
 	"os"
 	"sync"
 	"time"

src/cmd/discovery-registrar/app/config.go

@@ -37,7 +37,9 @@ func LoadConfig(log *log.Logger) Config {
 		log.Fatal(err)
 	}
 
-	envstruct.WriteReport(&cfg)
+	if err := envstruct.WriteReport(&cfg); err != nil {
+		log.Fatal(err)
+	}
 
 	return cfg
 }

src/cmd/discovery-registrar/app/registrar.go

@@ -4,7 +4,7 @@ import (
 	"fmt"
 	"log"
 	"net/http"
-	_ "net/http/pprof"
+	_ "net/http/pprof" // nolint:gosec
 	"time"
 
 	metrics "code.cloudfoundry.org/go-metric-registry"
@@ -55,7 +55,12 @@ func (r *DynamicRegistrar) Start(debugMetrics bool, pprofPort uint16) {
 	if debugMetrics {
 		r.metrics.RegisterDebugMetrics()
 		r.pprofServer = &http.Server{Addr: fmt.Sprintf("127.0.0.1:%d", pprofPort), Handler: http.DefaultServeMux}
-		go func() { r.pprofServer.ListenAndServe() }()
+		go func() {
+			err := r.pprofServer.ListenAndServe()
+			if err != http.ErrServerClosed {
+				log.Fatalf("pprof error: %s", err)
+			}
+		}()
 	}
 	ticker := time.NewTicker(r.publishInterval)
 
@@ -75,7 +80,7 @@ func (r *DynamicRegistrar) Start(debugMetrics bool, pprofPort uint16) {
 func (r *DynamicRegistrar) publishTargets() {
 	targets := r.targetProvider()
 	for _, t := range targets {
-		bytes, err := yaml.Marshal(&t)
+		bytes, err := yaml.Marshal(t)
 		if err != nil {
 			r.logger.Printf("unable to marshal target(%s): %s\n", t.Source, err)
 			continue

src/cmd/metrics-agent/app/config.go

@@ -1,7 +1,7 @@
 package app
 
 import (
-	"fmt"
+	"log"
 	"time"
 
 	"code.cloudfoundry.org/go-envstruct"
@@ -59,11 +59,14 @@ func LoadConfig() Config {
 			ExpirationInterval: time.Minute,
 		},
 	}
+
 	if err := envstruct.Load(&cfg); err != nil {
-		panic(fmt.Sprintf("Failed to load config from environment: %s", err))
+		log.Fatal(err)
 	}
 
-	envstruct.WriteReport(&cfg)
+	if err := envstruct.WriteReport(&cfg); err != nil {
+		log.Fatal(err)
+	}
 
 	return cfg
 }

src/cmd/metrics-agent/app/metrics_agent.go

@@ -6,7 +6,7 @@ import (
 	"fmt"
 	"log"
 	"net/http"
-	_ "net/http/pprof"
+	_ "net/http/pprof" // nolint:gosec
 	"time"
 
 	gendiodes "code.cloudfoundry.org/go-diodes"
@@ -244,7 +244,7 @@ func (m *MetricsAgent) Stop() {
 		defer cancelFunc()
 
 		if m.metricsServer != nil {
-			m.metricsServer.Shutdown(ctx)
+			_ = m.metricsServer.Shutdown(ctx)
 		}
 	}()
 

src/cmd/metrics-agent/app/metrics_agent_test.go

@@ -432,7 +432,8 @@ func newStubPromServer() *stubPromServer {
 func (s *stubPromServer) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	s.requestHeaders <- req.Header
 	s.requestPaths <- req.URL.Path
-	w.Write([]byte(s.resp))
+	_, err := w.Write([]byte(s.resp))
+	Expect(err).ToNot(HaveOccurred())
 }
 
 const promOutput = `

src/cmd/metrics-agent/main.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"log"
-	_ "net/http/pprof"
 	"os"
 	"time"
 

src/internal/gatherer/proxy.go

@@ -108,7 +108,7 @@ func (c *ProxyGatherer) scrape(scrapeConfig scraper.PromScraperConfig) ([]*io_pr
 	}
 
 	defer func() {
-		io.Copy(ioutil.Discard, resp.Body)
+		_, _ = io.Copy(ioutil.Discard, resp.Body)
 		resp.Body.Close()
 	}()
 

src/internal/gatherer/proxy_test.go

@@ -222,7 +222,8 @@ func newStubHttpsPromServer(scrapeCerts *testhelpers.TestCerts) *stubPromServer
 func (s *stubPromServer) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	s.requestHeaders <- req.Header
 	s.requestPaths <- req.URL.Path
-	w.Write([]byte(s.resp))
+	_, err := w.Write([]byte(s.resp))
+	Expect(err).ToNot(HaveOccurred())
 }
 
 func haveFamilyName(name string) types.GomegaMatcher {