* only alphanumeric chars and dash are allowed, everything else is re…

…placed with dash

* leading and trailing dashes are stripped
* added test
#240

pkg/fwdport/fwdport.go

@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"regexp"
 	"strconv"
+	"strings"
 	"sync"
 	"time"
 
@@ -250,14 +251,20 @@ func (pfo *PortForwardOpts) addHost(host string) {
 	// add host to /etc/hosts
 	pfo.HostFile.Hosts.AddHost(pfo.LocalIp.String(), host)
 
-	// replace illegal characters with underscore and add another entry if this changes the hostname
-	hostnameIllegalChars := regexp.MustCompile(`[^a-zA-Z0-9\-.]`)
-	sanitizedHost := hostnameIllegalChars.ReplaceAllString(host, `_`)
+	sanitizedHost := sanitizeHost(host)
 	if host != sanitizedHost {
 		pfo.addHost(sanitizedHost) //should recurse only once
 	}
 }
 
+// make sure any non-alphanumeric characters in the context name don't make it to the generated hostname
+func sanitizeHost(host string) string {
+	hostnameIllegalChars := regexp.MustCompile(`[^a-zA-Z0-9\-]`)
+	replacementChar := `-`
+	sanitizedHost := strings.Trim(hostnameIllegalChars.ReplaceAllString(host, replacementChar), replacementChar)
+	return sanitizedHost
+}
+
 // AddHosts adds hostname entries to /etc/hosts
 func (pfo *PortForwardOpts) AddHosts() {
 

pkg/fwdport/fwdport_test.go

@@ -0,0 +1,23 @@
+package fwdport
+
+import "testing"
+
+func Test_sanitizeHost(t *testing.T) {
+	tests := []struct {
+		contextName string
+		want        string
+	}{
+		{ // This is how Openshift generates context names
+			contextName: "service-name.namespace.project-name/cluster-name:6443/username",
+			want:        "service-name-namespace-project-name-cluster-name-6443-username",
+		},
+		{contextName: "-----test-----", want: "test"},
+	}
+	for _, tt := range tests {
+		t.Run("Sanitize hostname generated from context and namespace: "+tt.contextName, func(t *testing.T) {
+			if got := sanitizeHost(tt.contextName); got != tt.want {
+				t.Errorf("sanitizeHost() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}