cache: add cache.json to track cache metadata

Track partitions and images associated to a restore
operation through a cache.json file located in the
cache partition.

cache.json example contents:
{
    'images': [
        {
            'name': 'xxx.img',
            'disk': 1,
            'partition': 2
        },
        {
            'name': 'xxx.img',
            'disk': 1,
            'partition': 3
        }
    ]
}

Add class CacheDataFile to handle the cache.json
file.

Add an entry to the 'images' array each time a
restore operation is executed successfuly,
replace entries with the same disk/partition.

Remove entry to the 'images' array with image delete
operations.

Add image info to kiosk configuration. This enables
image restore operations. This information is not
retroactive, only newly restored images will enable
the restore button in Kiosk.

src/live/kiosk.py

@@ -10,17 +10,22 @@ kiosk_config = {}
 
 def update_kiosk_config(refresh_payload):
     from src.utils.probe import OSFamily
+    from src.utils.cache import CacheDataFile
+
+    data_file = CacheDataFile()
     os_list = []
     for part_setup in refresh_payload['partition_setup']:
         if part_setup['os_family'] == OSFamily.UNKNOWN.name:
             del part_setup['os_family']
             continue
+        partnum = int(part_setup['partition'])
+        disknum = int(part_setup['disk'])
         os_data = {
             'name': part_setup['os'],
-            'partition': int(part_setup['partition']),
-            'disk': int(part_setup['disk']),
+            'partition': partnum,
+            'disk': disknum,
             'os': part_setup['os_family'],
-            'image': ''
+            'image': data_file.get_image_name(disknum, partnum)
         }
         del part_setup['os_family']
         os_list.append(os_data)

src/live/ogOperations.py

@@ -619,6 +619,10 @@ class OgLiveOperations:
 
         extend_filesystem(disk, partition)
 
+        data_file = CacheDataFile()
+        data_file.add_entry(name + '.img', disk, partition)
+        data_file.save()
+
         if disk == 1:
             configure_os(disk, partition)
 
@@ -800,6 +804,11 @@ class OgLiveOperations:
                 logging.info(f'Removing checksum file {csum_path} from cache')
                 os.remove(csum_path)
 
+        data_file = CacheDataFile()
+        for image_name in images:
+            data_file.remove_image(image_name)
+        data_file.save()
+
         result = {'cache': self._get_cache_contents()}
 
         self._restartBrowser(self._url)

src/utils/cache.py

@@ -8,6 +8,7 @@
 
 import logging
 import shutil
+import json
 import os
 
 from src.utils.fs import mount_mkdir, umount
@@ -18,6 +19,7 @@ OG_IMAGE_PATH = '/opt/opengnsys/images/'
 OG_CACHE_PATH = '/opt/opengnsys/cache'
 OG_CACHE_IMAGE_PATH =  OG_CACHE_PATH + OG_IMAGE_PATH
 OGCLIENT_LOG_CACHE='/opt/opengnsys/log/{ip}.cache.txt'
+CACHE_FILE_NAME = 'cache.json'
 
 def mount_cache():
     cache_dev = get_cache_dev_path()
@@ -114,3 +116,61 @@ def update_live_cache():
             shutil.copyfile(server_file + sum_extension, client_file + sum_extension)
         else:
             logging.info(f'{client_file} is already up to date')
+
+class CacheDataFile:
+    def __init__(self):
+        self.file_path = os.path.join(OG_CACHE_IMAGE_PATH, CACHE_FILE_NAME)
+        self.data = {'images': []}
+
+        cache_mnt = mount_cache()
+        if not cache_mnt:
+            self.file_path = None
+            return
+
+        if os.path.exists(self.file_path):
+            self.load()
+        else:
+            self.save()
+
+    def load(self):
+        if not self.file_path:
+            return
+
+        try:
+            with open(self.file_path, 'r', encoding='utf-8') as f:
+                self.data = json.load(f)
+        except (json.JSONDecodeError, OSError):
+            self.data = {'images': []}
+
+    def add_entry(self, img_name, disknum, partnum):
+        new_entry = {'name': img_name, 'disk': disknum, 'partition': partnum}
+
+        filtered_images = []
+        for img in self.data['images']:
+            if img['disk'] != disknum and img['partition'] != partnum:
+                filtered_images.append(img)
+
+        self.data['images'] = filtered_images
+        self.data['images'].append(new_entry)
+
+    def remove_image(self, img_name):
+        filtered_images = []
+        for img in self.data['images']:
+            if img['name'] != img_name:
+                filtered_images.append(img)
+
+        self.data['images'] = filtered_images
+
+
+    def get_image_name(self, disknum, partnum):
+        for img in self.data['images']:
+            if img['disk'] == disknum and img['partition'] == partnum:
+                return img['name']
+        return ''
+
+    def save(self):
+        if not self.file_path:
+            return
+
+        with open(self.file_path, 'w', encoding='utf-8') as f:
+            json.dump(self.data, f, indent=2)