initialize using a k8s-friendly name derived from full service name

appsody/initializer.go

@@ -7,6 +7,8 @@ import (
 	"os"
 	"os/exec"
 	"strings"
+
+	"github.com/lkingland/faas/k8s"
 )
 
 // NameMappings are short-name to repository full name mappings,
@@ -39,11 +41,14 @@ func (n *Initializer) Initialize(name, language, path string) error {
 
 	// Appsody does not support domain names as the project name
 	// (ex: www.example.com), and has extremely strict naming requirements
-	// (only lower case letters, numbers and dashes).  So for now replace
+	// (subdomains per rfc 1035).  So let's just assume its name must be a valid domain, and
-	// any dots with dashes.
+	// encode it as a 1035 domain by doubling down on hyphens.
-	name = strings.ReplaceAll(name, ".", "-")
+	project, err := k8s.ToSubdomain(name)
+	if err != nil {
+		return err
+	}
 
-	// Dereference stack short name
+	// Dereference stack short name.  ex. "go" -> "go-ce-functions"
 	stackName, ok := stackShortNames[language]
 	if !ok {
 		languages := []string{}
@@ -56,13 +61,12 @@ func (n *Initializer) Initialize(name, language, path string) error {
 
 	// set up the command, specifying a sanitized project name and connecting
 	// standard output and error.
-	cmd := exec.Command("appsody", "init", "boson/"+stackName, "--project-name", name)
+	cmd := exec.Command("appsody", "init", "boson/"+stackName, "--project-name", project)
 	cmd.Dir = path
 
-	fmt.Println(cmd)
-
 	// If verbose logging is enabled, echo appsody's chatty stdout.
 	if n.Verbose {
+		fmt.Println(cmd)
 		cmd.Stdout = os.Stdout
 	}
 

k8s/names.go

@@ -0,0 +1,67 @@
+package k8s
+
+import (
+	"errors"
+	"strings"
+
+	"k8s.io/apimachinery/pkg/util/validation"
+)
+
+// ToSubdomain converts a domain to a subdomain.
+// If the input is not a valid domain an error is thrown.
+func ToSubdomain(in string) (string, error) {
+	if err := validation.IsFullyQualifiedDomainName(nil, in); err != nil {
+		return "", err.ToAggregate()
+	}
+
+	out := []rune{}
+	for _, c := range in {
+		// convert dots to hyphens
+		if c == '.' {
+			out = append(out, '-')
+		} else if c == '-' {
+			out = append(out, '-')
+			out = append(out, '-')
+		} else {
+			out = append(out, c)
+		}
+	}
+	return string(out), nil
+}
+
+// FromSubdomain converts a doman which has been encoded as
+// a subdomain using the algorithm of ToSubdoman back to a domain.
+// Input errors if not a 1035 label.
+func FromSubdomain(in string) (string, error) {
+	if errs := validation.IsDNS1035Label(in); len(errs) > 0 {
+		return "", errors.New(strings.Join(errs, ","))
+	}
+
+	rr := []rune(in)
+	out := []rune{}
+
+	for i := 0; i < len(rr); i++ {
+		c := rr[i]
+		if c == '-' {
+			// If the next rune is either nonexistent
+			// or not also a dash, this is an encoded dot.
+			if i+1 == len(rr) || rr[i+1] != '-' {
+				out = append(out, '.')
+				continue
+			}
+
+			// If the next rune is also a dash, this is
+			// an escaping dash, so append a slash, and
+			// increment the pointer such that the next
+			// loop begins with the next potential tuple.
+			if rr[i+1] == '-' {
+				out = append(out, '-')
+				i++
+				continue
+			}
+		}
+		out = append(out, c)
+	}
+
+	return string(out), nil
+}

k8s/names_test.go

@@ -0,0 +1,56 @@
+package k8s
+
+import "testing"
+
+// TestToSubdomain ensures that a valid domain name is
+// encoded into the expected subdmain.
+func TestToSubdomain(t *testing.T) {
+	cases := []struct {
+		In  string
+		Out string
+		Err bool
+	}{
+		{"", "", true},        // invalid domain
+		{"*", "", true},       // invalid domain
+		{"example", "", true}, // invalid domain
+		{"example.com", "example-com", false},
+		{"my-domain.com", "my--domain-com", false},
+	}
+
+	for _, c := range cases {
+		out, err := ToSubdomain(c.In)
+		if err != nil && !c.Err {
+			t.Fatalf("Unexpected error: %v", err)
+		}
+		if out != c.Out {
+			t.Fatalf("expected '%v' to yield '%v', got '%v'", c.In, c.Out, out)
+		}
+	}
+}
+
+// TestFromSubdomain ensures that a valid subdomain is decoded
+// back into a domain.
+func TestFromSubdomain(t *testing.T) {
+	cases := []struct {
+		In  string
+		Out string
+		Err bool
+	}{
+		{"", "", true},  // invalid subdomain
+		{"*", "", true}, // invalid subdomain
+		{"example-com", "example.com", false},
+		{"my--domain-com", "my-domain.com", false},
+		{"cdn----1-my--domain-com", "cdn--1.my-domain.com", false},
+	}
+
+	for _, c := range cases {
+		out, err := FromSubdomain(c.In)
+		if err != nil && !c.Err {
+			t.Fatalf("Unexpected error: %v", err)
+		}
+		if out != c.Out {
+			t.Fatalf("expected '%v' to yield '%v', got '%v'", c.In, c.Out, out)
+		}
+	}
+
+}