Test /etc/os-release first

On systems lsb_release could be patched to return a "compatible"
distribution, not the native one. so prefer the modern /etc/os-release
over lsb_release.

testinfra/modules/systeminfo.py

@@ -50,21 +50,6 @@ def sysinfo(self):
     def _get_linux_sysinfo(self):
         sysinfo = {}
 
-        # LSB
-        lsb = self.run("lsb_release -a")
-        if lsb.rc == 0:
-            for line in lsb.stdout.splitlines():
-                key, value = line.split(":", 1)
-                key = key.strip().lower()
-                value = value.strip().lower()
-                if key == "distributor id":
-                    sysinfo["distribution"] = value
-                elif key == "release":
-                    sysinfo["release"] = value
-                elif key == "codename":
-                    sysinfo["codename"] = value
-            return sysinfo
-
         # https://www.freedesktop.org/software/systemd/man/os-release.html
         os_release = self.run("cat /etc/os-release")
         if os_release.rc == 0:
@@ -100,6 +85,21 @@ def _get_linux_sysinfo(self):
             sysinfo["release"] = alpine_release.stdout.strip()
             return sysinfo
 
+        # LSB
+        lsb = self.run("lsb_release -a")
+        if lsb.rc == 0:
+            for line in lsb.stdout.splitlines():
+                key, value = line.split(":", 1)
+                key = key.strip().lower()
+                value = value.strip().lower()
+                if key == "distributor id":
+                    sysinfo["distribution"] = value
+                elif key == "release":
+                    sysinfo["release"] = value
+                elif key == "codename":
+                    sysinfo["codename"] = value
+            return sysinfo
+
         return sysinfo
 
     def _get_darwin_sysinfo(self):