Remove panic() and handle it appropriately (#5807)

This is an effort to remove panic from the source. 
Add a new call called CriticialIf, that calls LogIf and exits. 
Replace panics with one of CriticalIf, FatalIf and a return of error.

pkg/net/host.go

@@ -139,12 +139,3 @@ func ParseHost(s string) (*Host, error) {
 		IsPortSet: isPortSet,
 	}, nil
 }
-
-// MustParseHost - parses given string to Host, else panics.
-func MustParseHost(s string) *Host {
-	host, err := ParseHost(s)
-	if err != nil {
-		panic(err)
-	}
-	return host
-}

pkg/net/host_test.go

@@ -207,30 +207,3 @@ func TestParseHost(t *testing.T) {
 		}
 	}
 }
-
-func TestMustParseHost(t *testing.T) {
-	testCases := []struct {
-		s            string
-		expectedHost *Host
-	}{
-		{"play", &Host{"play", 0, false}},
-		{"play:0", &Host{"play", 0, true}},
-		{"play:9000", &Host{"play", 9000, true}},
-		{"play.minio.io", &Host{"play.minio.io", 0, false}},
-		{"play.minio.io:9000", &Host{"play.minio.io", 9000, true}},
-		{"147.75.201.93", &Host{"147.75.201.93", 0, false}},
-		{"147.75.201.93:9000", &Host{"147.75.201.93", 9000, true}},
-		{"play12", &Host{"play12", 0, false}},
-		{"12play", &Host{"12play", 0, false}},
-		{"play-minio-io", &Host{"play-minio-io", 0, false}},
-		{"play--minio.io", &Host{"play--minio.io", 0, false}},
-	}
-
-	for i, testCase := range testCases {
-		host := MustParseHost(testCase.s)
-
-		if !reflect.DeepEqual(host, testCase.expectedHost) {
-			t.Fatalf("test %v: host: expected: %#v, got: %#v", i+1, testCase.expectedHost, host)
-		}
-	}
-}

pkg/net/port.go

@@ -42,13 +42,3 @@ func ParsePort(s string) (p Port, err error) {
 
 	return Port(i), nil
 }
-
-// MustParsePort - parses string into Port, else panics
-func MustParsePort(s string) Port {
-	p, err := ParsePort(s)
-	if err != nil {
-		panic(err)
-	}
-
-	return p
-}

pkg/net/port_test.go

@@ -71,22 +71,3 @@ func TestParsePort(t *testing.T) {
 		}
 	}
 }
-
-func TestMustParsePort(t *testing.T) {
-	testCases := []struct {
-		s            string
-		expectedPort Port
-	}{
-		{"0", Port(0)},
-		{"9000", Port(9000)},
-		{"65535", Port(65535)},
-	}
-
-	for i, testCase := range testCases {
-		port := MustParsePort(testCase.s)
-
-		if port != testCase.expectedPort {
-			t.Fatalf("test %v: error: port: %v, got: %v", i+1, testCase.expectedPort, port)
-		}
-	}
-}

pkg/net/url.go

@@ -35,7 +35,10 @@ func (u URL) IsEmpty() bool {
 func (u URL) String() string {
 	// if port number 80 and 443, remove for http and https scheme respectively
 	if u.Host != "" {
-		host := MustParseHost(u.Host)
+		host, err := ParseHost(u.Host)
+		if err != nil {
+			panic(err)
+		}
 		switch {
 		case u.Scheme == "http" && host.Port == 80:
 			fallthrough