Efforts to make ucloud a python package

ucloud/sanity_checks.py

@@ -0,0 +1,33 @@
+import sys
+import subprocess as sp
+
+from os.path import isdir
+from ucloud.config import env_vars
+
+
+def check():
+    #########################
+    #  ucloud-image-scanner #
+    #########################
+    if env_vars.get('STORAGE_BACKEND') == 'filesystem' and not isdir(env_vars.get('IMAGE_DIR')):
+        print("You have set STORAGE_BACKEND to filesystem. So,"
+              "the {} must exists. But, it don't".format(env_vars.get('IMAGE_DIR')))
+        sys.exit(1)
+
+    try:
+        sp.check_output(['which', 'qemu-img'])
+    except Exception:
+        print("qemu-img missing")
+        sys.exit(1)
+
+    ###############
+    # ucloud-host #
+    ###############
+
+    if env_vars.get('STORAGE_BACKEND') == 'filesystem' and not isdir(env_vars.get('VM_DIR')):
+        print("You have set STORAGE_BACKEND to filesystem. So, the vm directory mentioned"
+              " in .env file must exists. But, it don't.")
+        sys.exit(1)
+
+if __name__ == "__main__":
+    check()