update methods in OSReleaseUtil (#1038)

src/main/java/emissary/util/os/OSReleaseUtil.java

@@ -2,6 +2,7 @@
 
 import org.apache.commons.lang3.StringUtils;
 
+import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Optional;
@@ -44,11 +45,11 @@ static String getVersionId(Path osReleasePath) {
      *
      * @return the major OS version
      */
-    public static String getMajorVersion() {
-        return getMajorVersion(OS_RELEASE_PATH);
+    public static String getMajorReleaseVersion() {
+        return getMajorReleaseVersion(OS_RELEASE_PATH);
     }
 
-    static String getMajorVersion(Path osReleasePath) {
+    static String getMajorReleaseVersion(Path osReleasePath) {
         return String.format("%.0f", Float.parseFloat(getVersionId(osReleasePath)));
     }
 
@@ -62,10 +63,40 @@ public static boolean isUbuntu() {
     }
 
     static boolean isUbuntu(Path osReleasePath) {
+        return isOsName(osReleasePath, "ubuntu");
+    }
+
+    /**
+     * Use the /etc/os-release file to determine if the OS is CentOS
+     *
+     * @return true if CentOS is found, false otherwise
+     */
+    public static boolean isCentOs() {
+        return isCentOs(OS_RELEASE_PATH);
+    }
+
+    static boolean isCentOs(Path osReleasePath) {
+        return isOsName(osReleasePath, "centos");
+    }
+
+    /**
+     * Use the /etc/os-release file to determine if the OS is RHEL
+     *
+     * @return true if RHEL is found, false otherwise
+     */
+    public static boolean isRhel() {
+        return isRhel(OS_RELEASE_PATH);
+    }
+
+    static boolean isRhel(Path osReleasePath) {
+        return isOsName(osReleasePath, "rhel");
+    }
+
+    private static boolean isOsName(Path osReleasePath, String osName) {
         if (Files.exists(osReleasePath)) {
             try (Stream<String> lines = Files.lines(osReleasePath)) {
-                return lines.anyMatch(s -> StringUtils.containsIgnoreCase(s, "ubuntu"));
-            } catch (Exception e) {
+                return lines.filter(line -> line.startsWith("ID=")).anyMatch(entry -> StringUtils.containsIgnoreCase(entry, osName));
+            } catch (IOException ignored) {
                 // ignore
             }
         }

src/test/java/emissary/util/os/OSReleaseUtilTest.java

@@ -2,6 +2,7 @@
 
 import emissary.util.io.ResourceReader;
 
+import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 
 import java.nio.file.Path;
@@ -12,33 +13,54 @@
 
 class OSReleaseUtilTest {
 
-    @Test
-    void testGetVersionId() throws Exception {
+    @SuppressWarnings("NonFinalStaticField")
+    static Path centos7Path;
+    @SuppressWarnings("NonFinalStaticField")
+    static Path rhel8Path;
+    @SuppressWarnings("NonFinalStaticField")
+    static Path ubuntu20Path;
+
+    @BeforeAll
+    static void getResources() throws Exception {
         ResourceReader rr = new ResourceReader();
 
-        assertEquals("7", OSReleaseUtil.getVersionId(Path.of(rr.getResource(rr.getResourceName(this.getClass().getPackage(), "centos7")).toURI())));
-        assertEquals("8.10", OSReleaseUtil.getVersionId(Path.of(rr.getResource(rr.getResourceName(this.getClass().getPackage(), "rhel8")).toURI())));
-        assertEquals("20.04",
-                OSReleaseUtil.getVersionId(Path.of(rr.getResource(rr.getResourceName(this.getClass().getPackage(), "ubuntu")).toURI())));
+        centos7Path = Path.of(rr.getResource(rr.getResourceName(OSReleaseUtil.class.getPackage(), "centos7")).toURI());
+        rhel8Path = Path.of(rr.getResource(rr.getResourceName(OSReleaseUtil.class.getPackage(), "rhel8")).toURI());
+        ubuntu20Path = Path.of(rr.getResource(rr.getResourceName(OSReleaseUtil.class.getPackage(), "ubuntu20")).toURI());
     }
 
     @Test
-    void testGetMajorVersion() throws Exception {
-        ResourceReader rr = new ResourceReader();
+    void testGetVersionId() {
+        assertEquals("7", OSReleaseUtil.getVersionId(centos7Path));
+        assertEquals("8.10", OSReleaseUtil.getVersionId(rhel8Path));
+        assertEquals("20.04", OSReleaseUtil.getVersionId(ubuntu20Path));
+    }
 
-        assertEquals("7",
-                OSReleaseUtil.getMajorVersion(Path.of(rr.getResource(rr.getResourceName(this.getClass().getPackage(), "centos7")).toURI())));
-        assertEquals("8", OSReleaseUtil.getMajorVersion(Path.of(rr.getResource(rr.getResourceName(this.getClass().getPackage(), "rhel8")).toURI())));
-        assertEquals("20",
-                OSReleaseUtil.getMajorVersion(Path.of(rr.getResource(rr.getResourceName(this.getClass().getPackage(), "ubuntu")).toURI())));
+    @Test
+    void testGetMajorVersion() {
+        assertEquals("7", OSReleaseUtil.getMajorReleaseVersion(centos7Path));
+        assertEquals("8", OSReleaseUtil.getMajorReleaseVersion(rhel8Path));
+        assertEquals("20", OSReleaseUtil.getMajorReleaseVersion(ubuntu20Path));
     }
 
     @Test
-    void testIsUbuntu() throws Exception {
-        ResourceReader rr = new ResourceReader();
+    void testIsUbuntu() {
+        assertFalse(OSReleaseUtil.isUbuntu(centos7Path));
+        assertFalse(OSReleaseUtil.isUbuntu(rhel8Path));
+        assertTrue(OSReleaseUtil.isUbuntu(ubuntu20Path));
+    }
 
-        assertFalse(OSReleaseUtil.isUbuntu(Path.of(rr.getResource(rr.getResourceName(this.getClass().getPackage(), "centos7")).toURI())));
-        assertFalse(OSReleaseUtil.isUbuntu(Path.of(rr.getResource(rr.getResourceName(this.getClass().getPackage(), "rhel8")).toURI())));
-        assertTrue(OSReleaseUtil.isUbuntu(Path.of(rr.getResource(rr.getResourceName(this.getClass().getPackage(), "ubuntu")).toURI())));
+    @Test
+    void testIsCentOS() {
+        assertTrue(OSReleaseUtil.isCentOs(centos7Path));
+        assertFalse(OSReleaseUtil.isCentOs(rhel8Path));
+        assertFalse(OSReleaseUtil.isCentOs(ubuntu20Path));
+    }
+
+    @Test
+    void testIsRhel() {
+        assertFalse(OSReleaseUtil.isRhel(centos7Path));
+        assertTrue(OSReleaseUtil.isRhel(rhel8Path));
+        assertFalse(OSReleaseUtil.isRhel(ubuntu20Path));
     }
 }