cli: add live management commands

Add new parameters to the config file ogcli.json with the
following default values:
'local_live': '/var/www/html/ogrelive'
'server_live': 'https://opengnsys.soleta.eu/ogrelive'

Add command to install the files of a live system. Example:
ogcli install live --name ogrelive-6.1.0-26

Perform an update if live files are already present.

Add command to delete the files of a live system. Example:
ogcli delete live --name ogrelive-6.1.0-26

Update ogcli list live to show the lives in the server when
invoked with the --remote flag. Example:
ogcli list live --remote

1 files changed, 20 insertions, 0 deletions

diff --git a/cli/utils.py b/cli/utils.py
index 3825583..380bd5b 100644
--- a/cli/utils.py
+++ b/cli/utils.py
@@ -8,7 +8,9 @@
 import unicodedata
 import json
 import ipaddress
+import hashlib
 import re
+import os
 
 def scope_lookup(scope_id, scope_type, d):
     if scope_id == d.get('id') and scope_type == d.get('type'):
@@ -69,3 +71,21 @@ def check_mac_address(addr):
 def remove_accents(text):
     normalized_text = unicodedata.normalize('NFD', text)
     return ''.join(c for c in normalized_text if unicodedata.category(c) != 'Mn')
+
+def compute_md5(path, bs=2**20):
+    if not os.path.exists(path):
+        print(f"Failed to calculate checksum, image file {path} does not exist")
+        return None
+
+    m = hashlib.md5()
+    try:
+        with open(path, 'rb') as f:
+            while True:
+                buf = f.read(bs)
+                if not buf:
+                    break
+                m.update(buf)
+    except Exception as e:
+        print(f'Failed to calculate checksum for {path}: {e}')
+        return None
+    return m.hexdigest()