RFR: os_linux.cpp parse_os_info gives non descriptive output on current SLES releases

[Baesken, Matthias]

Hello ,  the current implementation of the  parse_os_info-function in os_linux.cpp  gets the last line of a Linux-distro related file to
provide a meaningful OS version string.

However the information provided currently on SuSE Linux (SLES) is not very descriptive, it currently uses /etc/lsb-release and gives :

more /etc/lsb-release
LSB_VERSION="core-2.0-noarch:core-3.2-noarch:core-4.0-noarch:core-2.0-x86_64:core-3.2-x86_64:core-4.0-x86_64"

So I suggest to use /etc/SuSE-release instead, which gives a good information for
SLES 9 - 12 in the ***first line*** of  /etc/SuSE-release :

Example SLES11 :

more /etc/SuSE-release
SUSE Linux Enterprise Server 11 (x86_64)
VERSION = 11
PATCHLEVEL = 3

(this is similar to using /etc/redhat-release on Red Hat with the difference that the ***first line*** has the relevant info).


Additionally, /etc/os-release needs some special handling as well, because
the meaningful OS-release description string is not always  the last line of the file but in the line
containing the information PRETTY_NAME=...
See also :

https://www.freedesktop.org/software/systemd/man/os-release.html

Example from Ubuntu 14 :

$ more /etc/os-release
  ...
PRETTY_NAME="Ubuntu 14.04.3 LTS"
  ...

It might also be a good idea to place  /etc/os-release  higher in the distro_files list, but I do not have access to
turbolinux / gentoo to check the situation on these distros.

Regards, Matthias



Diff :
--- a/src/os/linux/vm/os_linux.cpp      Fri Apr 15 16:19:15 2016 +0100
+++ b/src/os/linux/vm/os_linux.cpp      Mon Apr 18 13:54:04 2016 +0200
@@ -2013,8 +2013,8 @@
// their own specific XXX-release file as well as a redhat-release file.
// Because of this the XXX-release file needs to be searched for before the
// redhat-release file.
-// Since Red Hat has a lsb-release file that is not very descriptive the
-// search for redhat-release needs to be before lsb-release.
+// Since Red Hat and SuSE have an lsb-release file that is not very descriptive the
+// search for redhat-release / SuSE-release needs to be before lsb-release.
// Since the lsb-release file is the new standard it needs to be searched
// before the older style release files.
// Searching system-release (Red Hat) and os-release (other Linuxes) are a
@@ -2031,8 +2031,8 @@
   "/etc/mandrake-release",
   "/etc/sun-release",
   "/etc/redhat-release",
+  "/etc/SuSE-release",
   "/etc/lsb-release",
-  "/etc/SuSE-release",
   "/etc/turbolinux-release",
   "/etc/gentoo-release",
   "/etc/ltib-release",
@@ -2065,11 +2065,36 @@
static void parse_os_info(char* distro, size_t length, const char* file) {
   FILE* fp = fopen(file, "r");
   if (fp != NULL) {
+    // SuSE-release : first line is interesting
+    // os-release : PRETTY_NAME= line is interesting
+    // (might be at different locations in the file)
     char buf[256];
-    // get last line of the file.
-    while (fgets(buf, sizeof(buf), fp)) { }
+    int lcnt = 0;
+    bool is_etc_suserelease = false;
+    bool is_etc_osrelease   = false;
+    if (strcmp(file, "/etc/SuSE-release") == 0) {
+      is_etc_suserelease = true;
+    }
+    if (strcmp(file, "/etc/os-release") == 0) {
+      is_etc_osrelease = true;
+    }
+
+    // get last line of the file or
+    // other interesting line on SUSE / os-release
+    while (fgets(buf, sizeof(buf), fp)) {
+      if (lcnt == 0 && is_etc_suserelease) {
+        break;
+      }
+      if (is_etc_osrelease) {
+        if (strstr(buf, "PRETTY_NAME=") != NULL) {
+          break;
+        }
+      }
+      lcnt++;
+    }
+
     // Edit out extra stuff in expected ubuntu format
-    if (strstr(buf, "DISTRIB_DESCRIPTION=") != NULL) {
+    if (strstr(buf, "DISTRIB_DESCRIPTION=") != NULL || strstr(buf, "PRETTY_NAME=") != NULL) {
       char* ptr = strstr(buf, "\"");  // the name is in quotes
       if (ptr != NULL) {
         ptr++; // go beyond first quote