Fix parsing lsb-release files

src/main/java/com/rapid7/container/analyzer/docker/os/Fingerprinter.java

@@ -73,10 +73,10 @@ private OperatingSystem parseOsRelease(InputStream input, String architecture) t
           String value = matcher.group("value");
           switch (name) {
             case "ID":
+            case "DISTRIB_ID":
               id = value.replaceAll("\"", "").toLowerCase();
               break;
             case "NAME":
-            case "DISTRIB_ID":
               product = value.replaceAll("\"", "");
               break;
             case "VERSION_ID":

src/test/java/com/rapid7/container/analyzer/docker/os/FingerprinterTest.java

@@ -118,4 +118,18 @@ void parseUbuntu() throws IOException {
     assertEquals("16.04", os.getVersion());
     assertEquals("Ubuntu Linux 16.04", os.getDescription());
   }
+
+  @Test
+  void parseUbuntuLsbRelease() throws IOException {
+    // Given
+    Fingerprinter fp = new Fingerprinter();
+
+    // When
+    OperatingSystem os = fp.parse(FingerprinterTest.class.getResourceAsStream("ubuntu-lsb-release.txt"), "/etc/lsb-release", "x86_64");
+
+    // Then
+    assertEquals("Ubuntu", os.getVendor());
+    assertEquals("16.04", os.getVersion());
+    assertEquals("Ubuntu Linux 16.04", os.getDescription());
+  }
 }

src/test/resources/com/rapid7/container/analyzer/docker/os/ubuntu-lsb-release.txt

@@ -0,0 +1,4 @@
+DISTRIB_ID=Ubuntu
+DISTRIB_RELEASE=16.04
+DISTRIB_CODENAME=xenial
+DISTRIB_DESCRIPTION="Ubuntu 16.04.6 LTS"