discovery: add port parameters

Currently the ACI spec only supports discovery on ports 443 and 80, this
does not allow using a discovery server on any other ports.

This commit adds an argument allowing for discovery on arbitrary ports.
If the argument is not specified (as in, is 0), the default ports are
used.

actool/discover.go

@@ -29,16 +29,19 @@ var (
 		Name:        "discover",
 		Description: "Discover the download URLs for an app",
 		Summary:     "Discover the download URLs for one or more app container images",
-		Usage:       "[--json] APP...",
+		Usage:       "[--json] [--port] [--insecure] APP...",
 		Run:         runDiscover,
 	}
+	flagPort uint
 )
 
 func init() {
 	cmdDiscover.Flags.BoolVar(&transportFlags.Insecure, "insecure", false,
 		"Don't check TLS certificates and allow insecure non-TLS downloads over http")
 	cmdDiscover.Flags.BoolVar(&outputJson, "json", false,
 		"Output result as JSON")
+	cmdDiscover.Flags.UintVar(&flagPort, "port", 0,
+		"Port to connect when performing discovery")
 }
 
 func runDiscover(args []string) (exit int) {
@@ -62,7 +65,7 @@ func runDiscover(args []string) (exit int) {
 		if transportFlags.Insecure {
 			insecure = discovery.InsecureTLS | discovery.InsecureHTTP
 		}
-		eps, attempts, err := discovery.DiscoverACIEndpoints(*app, nil, insecure)
+		eps, attempts, err := discovery.DiscoverACIEndpoints(*app, nil, insecure, flagPort)
 		if err != nil {
 			stderr("error fetching endpoints for %s: %s", name, err)
 			return 1

discovery/discovery.go

@@ -126,13 +126,13 @@ func createTemplateVars(app App) []string {
 	return tplVars
 }
 
-func doDiscover(pre string, hostHeaders map[string]http.Header, app App, insecure InsecureOption) (*discoveryData, error) {
+func doDiscover(pre string, hostHeaders map[string]http.Header, app App, insecure InsecureOption, port uint) (*discoveryData, error) {
 	app = *app.Copy()
 	if app.Labels["version"] == "" {
 		app.Labels["version"] = defaultVersion
 	}
 
-	_, body, err := httpsOrHTTP(pre, hostHeaders, insecure)
+	_, body, err := httpsOrHTTP(pre, hostHeaders, insecure, port)
 	if err != nil {
 		return nil, err
 	}
@@ -174,14 +174,15 @@ func doDiscover(pre string, hostHeaders map[string]http.Header, app App, insecur
 // DiscoverWalk will make HTTPS requests to find discovery meta tags and
 // optionally will use HTTP if insecure is set. hostHeaders specifies the
 // header to apply depending on the host (e.g. authentication). Based on the
-// response of the discoverFn it will continue to recurse up the tree.
-func DiscoverWalk(app App, hostHeaders map[string]http.Header, insecure InsecureOption, discoverFn DiscoverWalkFunc) (dd *discoveryData, err error) {
+// response of the discoverFn it will continue to recurse up the tree. If port
+// is 0, the default port will be used.
+func DiscoverWalk(app App, hostHeaders map[string]http.Header, insecure InsecureOption, port uint, discoverFn DiscoverWalkFunc) (dd *discoveryData, err error) {
 	parts := strings.Split(string(app.Name), "/")
 	for i := range parts {
 		end := len(parts) - i
 		pre := strings.Join(parts[:end], "/")
 
-		dd, err = doDiscover(pre, hostHeaders, app, insecure)
+		dd, err = doDiscover(pre, hostHeaders, app, insecure, port)
 		if derr := discoverFn(pre, dd, err); derr != nil {
 			return dd, derr
 		}
@@ -217,8 +218,8 @@ func walker(attempts *[]FailedAttempt, testFn DiscoverWalkFunc) DiscoverWalkFunc
 // tags and optionally will use HTTP if insecure is set. hostHeaders
 // specifies the header to apply depending on the host (e.g. authentication).
 // It will not give up until it has exhausted the path or found an image
-// discovery.
-func DiscoverACIEndpoints(app App, hostHeaders map[string]http.Header, insecure InsecureOption) (ACIEndpoints, []FailedAttempt, error) {
+// discovery. If port is 0, the default port will be used.
+func DiscoverACIEndpoints(app App, hostHeaders map[string]http.Header, insecure InsecureOption, port uint) (ACIEndpoints, []FailedAttempt, error) {
 	testFn := func(pre string, dd *discoveryData, err error) error {
 		if len(dd.ACIEndpoints) != 0 {
 			return errEnough
@@ -227,7 +228,7 @@ func DiscoverACIEndpoints(app App, hostHeaders map[string]http.Header, insecure
 	}
 
 	attempts := []FailedAttempt{}
-	dd, err := DiscoverWalk(app, hostHeaders, insecure, walker(&attempts, testFn))
+	dd, err := DiscoverWalk(app, hostHeaders, insecure, port, walker(&attempts, testFn))
 	if err != nil && err != errEnough {
 		return nil, attempts, err
 	}
@@ -239,7 +240,8 @@ func DiscoverACIEndpoints(app App, hostHeaders map[string]http.Header, insecure
 // tags and optionally will use HTTP if insecure is set. hostHeaders
 // specifies the header to apply depending on the host (e.g. authentication).
 // It will not give up until it has exhausted the path or found an public key.
-func DiscoverPublicKeys(app App, hostHeaders map[string]http.Header, insecure InsecureOption) (PublicKeys, []FailedAttempt, error) {
+// If port is 0, the default port will be used.
+func DiscoverPublicKeys(app App, hostHeaders map[string]http.Header, insecure InsecureOption, port uint) (PublicKeys, []FailedAttempt, error) {
 	testFn := func(pre string, dd *discoveryData, err error) error {
 		if len(dd.PublicKeys) != 0 {
 			return errEnough
@@ -248,7 +250,7 @@ func DiscoverPublicKeys(app App, hostHeaders map[string]http.Header, insecure In
 	}
 
 	attempts := []FailedAttempt{}
-	dd, err := DiscoverWalk(app, hostHeaders, insecure, walker(&attempts, testFn))
+	dd, err := DiscoverWalk(app, hostHeaders, insecure, port, walker(&attempts, testFn))
 	if err != nil && err != errEnough {
 		return nil, attempts, err
 	}

discovery/discovery_test.go

@@ -549,7 +549,7 @@ func TestDiscoverEndpoints(t *testing.T) {
 			InsecureTLS | InsecureHTTP,
 		}
 		for _, insecure := range insecureList {
-			eps, _, err := DiscoverACIEndpoints(tt.app, hostHeaders, insecure)
+			eps, _, err := DiscoverACIEndpoints(tt.app, hostHeaders, insecure, 0)
 			if err != nil && !tt.expectDiscoveryACIEndpointsSuccess {
 				continue
 			}
@@ -559,7 +559,7 @@ func TestDiscoverEndpoints(t *testing.T) {
 			if err != nil {
 				t.Fatalf("#%d DiscoverACIEndpoints failed: %v", i, err)
 			}
-			publicKeys, _, err := DiscoverPublicKeys(tt.app, hostHeaders, insecure)
+			publicKeys, _, err := DiscoverPublicKeys(tt.app, hostHeaders, insecure, 0)
 			if err != nil && !tt.expectDiscoveryPublicKeysSuccess {
 				continue
 			}

discovery/http.go

@@ -21,6 +21,7 @@ import (
 	"net"
 	"net/http"
 	"net/url"
+	"strconv"
 	"time"
 )
 
@@ -75,13 +76,16 @@ func init() {
 	httpDoInsecureTLS = ClientInsecureTLS
 }
 
-func httpsOrHTTP(name string, hostHeaders map[string]http.Header, insecure InsecureOption) (urlStr string, body io.ReadCloser, err error) {
-	fetch := func(scheme string) (urlStr string, res *http.Response, err error) {
+func httpsOrHTTP(name string, hostHeaders map[string]http.Header, insecure InsecureOption, port uint) (urlStr string, body io.ReadCloser, err error) {
+	fetch := func(scheme string, port uint) (urlStr string, res *http.Response, err error) {
 		u, err := url.Parse(scheme + "://" + name)
 		if err != nil {
 			return "", nil, err
 		}
 		u.RawQuery = "ac-discovery=1"
+		if port != 0 {
+			u.Host += ":" + strconv.FormatUint(uint64(port), 10)
+		}
 		urlStr = u.String()
 		req, err := http.NewRequest("GET", urlStr, nil)
 		if err != nil {
@@ -102,11 +106,11 @@ func httpsOrHTTP(name string, hostHeaders map[string]http.Header, insecure Insec
 			res.Body.Close()
 		}
 	}
-	urlStr, res, err := fetch("https")
+	urlStr, res, err := fetch("https", port)
 	if err != nil || res.StatusCode != http.StatusOK {
 		if insecure&InsecureHTTP != 0 {
 			closeBody(res)
-			urlStr, res, err = fetch("http")
+			urlStr, res, err = fetch("http", port)
 		}
 	}
 

discovery/http_test.go

@@ -194,7 +194,7 @@ func TestHTTPSOrHTTP(t *testing.T) {
 		hostHeaders := map[string]http.Header{
 			tt.name: tt.authHeader,
 		}
-		urlStr, body, err := httpsOrHTTP(tt.name, hostHeaders, tt.insecure)
+		urlStr, body, err := httpsOrHTTP(tt.name, hostHeaders, tt.insecure, 0)
 		if tt.expectSuccess {
 			if err != nil {
 				t.Fatalf("#%d httpsOrHTTP failed: %v", i, err)