Direct check for key in os_release_dict

[nishakm]

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Description
The find_os_release function parses an os_release file into a dictionary so the
"PRETTY_NAME" can be extracted from it. Rather than checking for "PRETTY_NAME"
in the dictionary's keys, we iterate over the dictionary directly to improve performance.

Implementation
Make the following changes in tern/analyze/default/container/single_layer.py:

 30 def find_os_release(host_path):                                                 
 31     """Find the OS PRETTY_NAME in the given path. If no os-release file         
 32     exists, return an empty string"""                                           
 33     # os-release may exist under /etc/ or /usr/lib. We should first check       
 34     # for the preferred /etc/os-release and fall back on /usr/lib/os-release    
 35     # if it does not exist under /etc                                           
 36     etc_path = os.path.join(host_path, constants.etc_release_path)              
 37     lib_path = os.path.join(host_path, constants.lib_release_path)              
 38     if not os.path.exists(etc_path):                                            
 39         if not os.path.exists(lib_path):                                        
 40             return ''                                                           
 41         etc_path = lib_path                                                     
 42     # file exists at this point, try to read it                                 
 43     with open(etc_path, 'r', encoding='utf-8') as f:                            
 44         lines = f.readlines()                                                   
 45     # Create dictionary from os-release values                                  
 46     os_release_dict = {}                                                        
 47     for line in lines:                                                          
 48         line = line.strip()                                                     
 49         if line:                                                                
 50             key, val = line.split('=', 1)                                       
 51             os_release_dict[key] = val.strip('"')                               
 52     pretty_name = ''                                                            
 53     if "PRETTY_NAME" in os_release_dict.keys(): <-- change to os_release_dict                         
 54         if os_release_dict["PRETTY_NAME"] == "Distroless":                      
 55             pretty_name = "{0} - {1}".format(os_release_dict["PRETTY_NAME"],    
 56                                              os_release_dict['VERSION'])        
 57         else:                                                                   
 58             pretty_name = os_release_dict["PRETTY_NAME"]                        
 59     return pretty_name.strip('"') 

[hlumapas]

Hello can I be assigned this issue for GH OSD?