[spp] [PATCH 10/29] tools/sppc: version checker for container DPDK ver

[Yasufumi Ogawa <yasufum.o@gmail.com>]

You need to check version of DPDK on a container because some of
application might be deprecated or removed from some specific version.
For instance, load balancer example app was removed after v19.08-rc.

This update is to add methods for getting DPDK version from container,
and comparing it with expected version.

Signed-off-by: Yasufumi Ogawa <yasufum.o@gmail.com>
---
 tools/sppc/lib/app_helper.py | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/tools/sppc/lib/app_helper.py b/tools/sppc/lib/app_helper.py
index cc042e5..b918aeb 100644
--- a/tools/sppc/lib/app_helper.py
+++ b/tools/sppc/lib/app_helper.py
@@ -4,6 +4,7 @@
 from . import common
 import os
 import secrets
+import subprocess
 import sys
 
 
@@ -337,6 +338,34 @@ def gen_sppc_file_prefix(app_name):
     return 'sppc-{}-{}'.format(app_name, secrets.token_hex(8))
 
 
+def get_dpdk_ver_in_container(rte_sdk, c_image):
+    """Get DPDK version on a container.
+
+    The version is retrieved by reading `${RTE_SDK/VERION` file.
+    """
+
+    cmd = ['cat', '{:s}/VERSION'.format(rte_sdk)]
+    cmd = ['docker', 'run', '-it', c_image] + cmd
+    # Decode the result of byte type to utf-8.
+    return subprocess.check_output(cmd).decode('utf-8').strip()
+
+
+def compare_version(expected, target):
+    """Compare given versions.
+
+    If two versions are equal, return 0. On the other hand, return -1 if
+    expected ver is less than target, or return 1.
+    """
+
+    from distutils.version import LooseVersion
+    if LooseVersion(expected) == LooseVersion(target):
+        return 0
+    elif LooseVersion(expected) < LooseVersion(target):
+        return 1
+    else:
+        return -1
+
+
 def _uniq(dup_list):
     """Remove duplicated elements in a list and return a unique list.
 
-- 
2.17.1