[Libguestfs] [PATCH] inspection: fix CentOS 7 detection

[Pino Toscano]

In newer CentOS 7 versions /etc/redhat-release says that the distro is
derived from RHEL, so we need to look at /etc/centos-release for
actually identifying it as CentOS.

The old code is needed as sub-case of /etc/redhat-release, as on
CentOS < 7 that file is a symlink to /etc/centos-release.
---
 src/inspect-fs-unix.c | 32 ++++++++++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/src/inspect-fs-unix.c b/src/inspect-fs-unix.c
index 2abbf24..f0fe141 100644
--- a/src/inspect-fs-unix.c
+++ b/src/inspect-fs-unix.c
@@ -345,8 +345,8 @@ guestfs_int_check_linux_root (guestfs_h *g, struct inspect_fs *fs)
       goto skip_release_checks;
   }
 
-  /* Oracle Linux includes a "/etc/redhat-release" file, hence the Oracle check
-   * needs to be performed before the Red-Hat one.
+  /* RHEL-based distros include a "/etc/redhat-release" file, hence their
+   * checks need to be performed before the Red-Hat one.
    */
   if (guestfs_is_file_opts (g, "/etc/oracle-release",
                             GUESTFS_IS_FILE_OPTS_FOLLOWSYMLINKS, 1, -1) > 0) {
@@ -376,6 +376,34 @@ guestfs_int_check_linux_root (guestfs_h *g, struct inspect_fs *fs)
       fs->minor_version = 0;
     }
   }
+  else if (guestfs_is_file_opts (g, "/etc/centos-release",
+                                 GUESTFS_IS_FILE_OPTS_FOLLOWSYMLINKS, 1, -1) > 0) {
+    fs->distro = OS_DISTRO_CENTOS;
+
+    if (parse_release_file (g, fs, "/etc/centos-release") == -1)
+      return -1;
+
+    if (match2 (g, fs->product_name, re_centos_old, &major, &minor) ||
+             match2 (g, fs->product_name, re_centos, &major, &minor)) {
+      fs->major_version = guestfs_int_parse_unsigned_int (g, major);
+      free (major);
+      if (fs->major_version == -1) {
+        free (minor);
+        return -1;
+      }
+      fs->minor_version = guestfs_int_parse_unsigned_int (g, minor);
+      free (minor);
+      if (fs->minor_version == -1)
+        return -1;
+    }
+    else if ((major = match1 (g, fs->product_name, re_centos_no_minor)) != NULL) {
+      fs->major_version = guestfs_int_parse_unsigned_int (g, major);
+      free (major);
+      if (fs->major_version == -1)
+        return -1;
+      fs->minor_version = 0;
+    }
+  }
   else if (guestfs_is_file_opts (g, "/etc/redhat-release",
                                  GUESTFS_IS_FILE_OPTS_FOLLOWSYMLINKS, 1, -1) > 0) {
     fs->distro = OS_DISTRO_REDHAT_BASED; /* Something generic Red Hat-like. */
-- 
2.1.0