generateRouteHostRegexp: Escape blanks

Escape spaces, tabs, carriage returns, and linefeeds in the regular
expression for a route's path in HAProxy map files in order to ensure that
HAProxy can parse the resulting map files correctly.

Follow-up to commit 019c5ac.

This commit fixes bug 2074304.

https://bugzilla.redhat.com/show_bug.cgi?id=2074304

* pkg/router/template/util/haproxy/map_entry_test.go
(TestGenerateHttpRedirectMapEntry): Add a test with a path with a space, a
test with a path with a tab, a test with a path with a carriage return, and
a test with a path with a linefeed.
* pkg/router/template/util/util.go (GenerateRouteRegexp): Escape spaces,
tabs, carriage returns, and linefeeds in the pattern for the route's path.

pkg/router/template/util/haproxy/map_entry_test.go

@@ -420,6 +420,38 @@ func TestGenerateHttpRedirectMapEntry(t *testing.T) {
 			wildcard:    false,
 			expectedKey: `^www\.example\.test\.?(:[0-9]+)?/x/y/z(/.*)?$`,
 		},
+		{
+			name:        "host with path with a space",
+			backendKey:  "test_host_path_with_space",
+			hostname:    "www.example.test",
+			path:        "/x y",
+			wildcard:    false,
+			expectedKey: `^www\.example\.test\.?(:[0-9]+)?/x\x20y(/.*)?$`,
+		},
+		{
+			name:        "host with path with a tab",
+			backendKey:  "test_host_path_with_tab",
+			hostname:    "www.example.test",
+			path:        "/x\ty",
+			wildcard:    false,
+			expectedKey: `^www\.example\.test\.?(:[0-9]+)?/x\ty(/.*)?$`,
+		},
+		{
+			name:        "host with path with a CR",
+			backendKey:  "test_host_path_with_cr",
+			hostname:    "www.example.test",
+			path:        "/x\ry",
+			wildcard:    false,
+			expectedKey: `^www\.example\.test\.?(:[0-9]+)?/x\ry(/.*)?$`,
+		},
+		{
+			name:        "host with path with a LF",
+			backendKey:  "test_host_path_with_lf",
+			hostname:    "www.example.test",
+			path:        "/x\ny",
+			wildcard:    false,
+			expectedKey: `^www\.example\.test\.?(:[0-9]+)?/x\ny(/.*)?$`,
+		},
 		{
 			name:        "wildcard host",
 			backendKey:  "test_wildcard_host",

pkg/router/template/util/util.go

@@ -51,6 +51,14 @@ func GenerateRouteRegexp(hostname, path string, wildcard bool) string {
 		subpathRE = "(/.*)?"
 	}
 
+	// The path could contain space characters, which must be escaped in
+	// HAProxy map files.  See
+	// <https://bugzilla.redhat.com/show_bug.cgi?id=2074304>.
+	pathRE = strings.ReplaceAll(pathRE, ` `, `\x20`)
+	pathRE = strings.ReplaceAll(pathRE, "\t", `\t`)
+	pathRE = strings.ReplaceAll(pathRE, "\r", `\r`)
+	pathRE = strings.ReplaceAll(pathRE, "\n", `\n`)
+
 	return "^" + hostRE + portRE + pathRE + subpathRE + "$"
 }