[Fuego] [PATCH v2] need_check: add linux distro automatic detection

[Daniel Sangorrin]

This function can be used by tests that need to know the
distribution in the target board. The automatic detection
can be disabled/overriden by manually setting the variables
BOARD_DISTRO_ID and BOARD_DISTRO_VERSION_ID in the board
file.

IMPORTANT: this is not a substitute for individual command
checks. For example, even if the BOARD_DISTRO_ID is "debian"
test writers should still check for the existance of "apt-get"
in case they want to use it.

Signed-off-by: Daniel Sangorrin <daniel.sangorrin at toshiba.co.jp>
---
 engine/scripts/need_check.sh | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/engine/scripts/need_check.sh b/engine/scripts/need_check.sh
index 1fd6d6d..2b00d46 100755
--- a/engine/scripts/need_check.sh
+++ b/engine/scripts/need_check.sh
@@ -123,6 +123,33 @@ function get_free_storage {
   echo $result
 }
 
+# This function detects the Linux distribution used on the target board and
+# exports the following variables:
+#    BOARD_DISTRO_ID (e.g. ubuntu, debian, centos)
+#    BOARD_DISTRO_VERSION_ID (e.g. "16.04", "8", "7")
+#
+# If the distribution cannot be automatically detected it will return 1.
+# Defining BOARD_DISTRO_ID and BOARD_DISTRO_VERSION_ID on the board file
+# disables automatic detection.
+function check_distro {
+    if [ -z "$BOARD_DISTRO_ID" ] || [ -z "$BOARD_DISTRO_VERSION_ID" ]; then
+        os_release_tmpfile=$(mktemp)
+        if get "/etc/os-release" $os_release_tmpfile ; then
+            export BOARD_DISTRO_ID="$(grep ^ID= $os_release_tmpfile | cut -c 4-)"
+            export BOARD_DISTRO_VERSION_ID="$(grep ^VERSION_ID= $os_release_tmpfile | cut -c 12-)"
+        fi
+        rm $os_release_tmpfile
+    fi
+
+    if [ -z "$BOARD_DISTRO_ID" ] || [ -z "$BOARD_DISTRO_VERSION_ID" ]; then
+            echo "ERROR: could not detect the distribution running on the board."
+            echo "Define BOARD_DISTRO_ID and BOARD_DISTRO_VERSION_ID in your board file."
+            return 1
+    else
+        echo "Board distribution is $BOARD_DISTRO_ID $BOARD_DISTRO_VERSION_ID"
+    fi
+}
+
 # $1 has a single string holding a space-separated args:
 #   arg1 = size
 #   arg2 = directory to check
-- 
2.7.4