Support detecting region from FIPS URLs (#1663)

Signed-off-by: Balasankar 'Balu' C <balu@dravidam.net>

pkg/s3utils/utils.go

@@ -89,6 +89,12 @@ var amazonS3HostHyphen = regexp.MustCompile(`^s3-(.*?).amazonaws.com$`)
 // amazonS3HostDualStack - regular expression used to determine if an arg is s3 host dualstack.
 var amazonS3HostDualStack = regexp.MustCompile(`^s3.dualstack.(.*?).amazonaws.com$`)
 
+// amazonS3HostFIPS - regular expression used to determine if an arg is s3 FIPS host.
+var amazonS3HostFIPS = regexp.MustCompile(`^s3-fips.(.*?).amazonaws.com$`)
+
+// amazonS3HostFIPSDualStack - regular expression used to determine if an arg is s3 FIPS host dualstack.
+var amazonS3HostFIPSDualStack = regexp.MustCompile(`^s3-fips.dualstack.(.*?).amazonaws.com$`)
+
 // amazonS3HostDot - regular expression used to determine if an arg is s3 host in . style.
 var amazonS3HostDot = regexp.MustCompile(`^s3.(.*?).amazonaws.com$`)
 
@@ -126,6 +132,18 @@ func GetRegionFromURL(endpointURL url.URL) string {
 	if len(parts) > 1 {
 		return parts[1]
 	}
+	if IsAmazonFIPSUSEastWestEndpoint(endpointURL) {
+		// We check for FIPS dualstack matching first to avoid the non-greedy
+		// regex for FIPS non-dualstack matching a dualstack URL
+		parts = amazonS3HostFIPSDualStack.FindStringSubmatch(endpointURL.Host)
+		if len(parts) > 1 {
+			return parts[1]
+		}
+		parts = amazonS3HostFIPS.FindStringSubmatch(endpointURL.Host)
+		if len(parts) > 1 {
+			return parts[1]
+		}
+	}
 	parts = amazonS3HostHyphen.FindStringSubmatch(endpointURL.Host)
 	if len(parts) > 1 {
 		return parts[1]

pkg/s3utils/utils_test.go

@@ -115,6 +115,18 @@ func TestGetRegionFromURL(t *testing.T) {
 			},
 			expectedRegion: "us-east-1",
 		},
+		{
+			u: url.URL{
+				Host: "s3-fips.us-east-1.amazonaws.com",
+			},
+			expectedRegion: "us-east-1",
+		},
+		{
+			u: url.URL{
+				Host: "s3-fips.dualstack.us-west-1.amazonaws.com",
+			},
+			expectedRegion: "us-west-1",
+		},
 	}
 
 	for i, testCase := range testCases {