fix: allow sharing ports >9999 (#22273)

Closes https://github.com/coder/coder/issues/22267

coderd/workspaceapps/appurl/appurl.go

@@ -19,7 +19,10 @@ var (
 	appURL = regexp.MustCompile(fmt.Sprintf(
 		`^(?P<AppSlug>%[1]s)(?:--(?P<AgentName>%[1]s))?--(?P<WorkspaceName>%[1]s)--(?P<Username>%[1]s)$`,
 		nameRegex))
-	PortRegex = regexp.MustCompile(`^\d{4}s?$`)
+	// PortRegex should not be able to be greater than 65535. In usage though, if a
+	// user tries to use a greater port, the proxy will just block it and not cause
+	// any issues. This is a good enough regex check.
+	PortRegex = regexp.MustCompile(`^\d{4,5}s?$`)
 
 	validHostnameLabelRegex = regexp.MustCompile(`^[a-z0-9]([-a-z0-9]*[a-z0-9])?$`)
 )

coderd/workspaceapps/appurl/appurl_test.go

@@ -193,6 +193,16 @@ func TestParseSubdomainAppURL(t *testing.T) {
 				Username:      "user",
 			},
 		},
+		{
+			Name:      "Port(5)--Agent--Workspace--User",
+			Subdomain: "12412--agent--workspace--user",
+			Expected: appurl.ApplicationURL{
+				AppSlugOrPort: "12412",
+				AgentName:     "agent",
+				WorkspaceName: "workspace",
+				Username:      "user",
+			},
+		},
 		{
 			Name:      "Port--Agent--Workspace--User",
 			Subdomain: "8080s--agent--workspace--user",
@@ -225,11 +235,11 @@ func TestParseSubdomainAppURL(t *testing.T) {
 			},
 		},
 		{
-			Name:      "5DigitAppSlug--Workspace--User",
-			Subdomain: "30000--workspace--user",
+			Name:      "5DigitPort--agent--Workspace--User",
+			Subdomain: "30000--agent--workspace--user",
 			Expected: appurl.ApplicationURL{
 				AppSlugOrPort: "30000",
-				AgentName:     "",
+				AgentName:     "agent",
 				WorkspaceName: "workspace",
 				Username:      "user",
 			},
@@ -599,6 +609,14 @@ func TestURLGenerationVsParsing(t *testing.T) {
 			Name:           "5DigitAppSlug_AgentOmittedInParsing",
 			AppSlugOrPort:  "30000",
 			AgentName:      "agent",
+			ExpectedParsed: "agent",
+		},
+		{
+			// 6 digits is not a valid port, so it is treated as an app slug.
+			// App slugs do not require the agent name, so it is dropped
+			Name:           "6DigitAppSlug_AgentOmittedInParsing",
+			AppSlugOrPort:  "300000",
+			AgentName:      "agent",
 			ExpectedParsed: "",
 		},
 	}