Develop Reference

Azure Functions : Local Development : Microsoft.WindowsAzure.Storage: Calculated MD5 does not match existing property

I am writing some Azure functions locally which I build into a Docker Image.
All has been working fine up until now when one fails to run locally. (Builds, but doesn't run). It is a Timer function (there are 3 timers and 2 http which all work)
It gives an error saying:
[31/03/2020 07:52:36] The listener for function 'IndexSites' was unable to start.
[31/03/2020 07:52:36] The listener for function 'IndexSites' was unable to start. Microsoft.WindowsAzure.Storage: Calculated MD5 does not match existing property.
I am not using any files, and this is running locally.
I have tried to clear the Azure Storage emulator but not sure what that is being used for (Only talking to Mongo).

Deployed app function has empty host.json and no host keys

I'm having a weird issue with my Azure App Function and I can't find anything on this.
I republished my function without changing its code, but suddenly the function stopped working and I'm getting this message as soon as I navigate to the function's page on Azure:
Error:
Error retrieving master key.
If I navigate to the function's settings, I can see that no keys have been generated and that host.json file is emptpy. Browsing my functions' files using Kudu, however, shows that file contents are correct.
Two more things make this weirder:
The function correctly works locally
If I take the code for another function and I deploy it on this one, my function works correctly, meaning that it's not an issue related to my function's configuration but rather to its code
Do you guys have any pointer on this?
EDIT:
Let me add more details on this.
Let's say I have 2 solutions, A.sln and B.sln.
I also have 2 App Functions on Azure, let's say F_1 and F_2.
A.sln and B.sln have the very same structure, the only difference is in business logic.
Same applies for F_1 and F_2, their only differences are the related storage accounts, as each function has its own.
Currently A.sln is deployed on F_1 and B.sln on F_2, and the only one working is F_1.
If I deploy A.sln on F_2, F_2 starts working, so my idea is that there's something wrong in B.sln's code because A.sln works with the very same configuration.

The Function App has a reference to a Storage account in application settings AzureWebJobsDashboard, AzureWebJobsStorage and WEBSITE_CONTENTAZUREFILECONNECTIONSTRING (if you are running on a consumption plan). Either clearing out this storage or simply recreating it fixed the problem.
I would also recommend creating separate storage accounts for every Function app - at least as long as these hard-to-find bugs are present. It is a lot easier to fix these kind of issues when they are only affecting a single Function app.

I don't know if this is the case here, but I found out that in my case (new deployment of Function App v3) host.json is empty on Azure, if there is a comment line in it. Removing comments solved my problem and host.json file is now deployed properly.

One of the reasons could be, the key inside the storage account might have been rotated. So, the connection strings referenced inside the AzureWebJobsDashboard and AzureWebJobsStorage of the azure function will be different.
Solution: Go to the storage account referenced in AzureWebJobsDashboard and AzureWebJobsStorage -> Access Keys -> Copy the connection string under key1 and use this for the AzureWebJobsDashboard and AzureWebJobsStorage.

Console Application crashes remotely but works locally

I have a console application in c#, .Net which I am currently using as a scheduled job.
The idea of this scheduled job is to fetch data and update data.
My solution contains the following:
Web (Mvc)
Contract (models etc)
Datalayer (Database)
Api
Console Application
My issue:
When I am running my Console application I am refering to a dll from 1 Web(mvc). Everything looks good when I am doing this locally,
but when I zip the catalog, drag this to my remote server and try to run it, I get the following exception:
Input string was not in a correct format in double.Parse
Basically these lines of code does not run properly on my remote server:
var weapons = new Weapons();
userWeapon = weapons.Where(x => x.WeaponId== userWeapons.WeaponId).FirstOrDefault();
var parsedValue = Convert.ToDouble(userWeapon.damage);
I mean, how is this possible? Why do I get this error remotely but not locally?
If you have any ideas on why this is occuring, please let me know.
Cheers!

Windows service can't write to %LOCALAPPDATA%

I have built an app that works only when not run as a Windows service. Well, the service runs, but it doesn't do what it should. The service uses the Local Service account. So to kick off debugging, I thought I'd start with something simple: have it create a directory when it starts:
Directory.CreateDirectory(
Environment.SpecialFolder.LocalApplicationData + "\\MyService");
When I started the service, it stopped almost immediately and Windows reported that fact. When I commented out the above statement, recompiled and re-installed, the service ran without stopping.
Obviously the above line throws an exception of some sort. I have no way of logging the error because I can't write to the file system. Any ideas why Local Service can't create a directory in its own %LOCALAPPDATA%?

You should use GetFolderPath with LocalApplicationData like so:
string folderName = Path.Combine(Environment.GetFolderPath(
Environment.SpecialFolder.LocalApplicationData),
"MyService");
Directory.CreateDirectory(folderName)

I think this might be because there is no special folder. When running as the local service account you are running under that user, not the logged in user. so you are requesting a special folder that probably wont exist, as I don't think the local service has a profile. (I may be wrong) - I was wrong :p
Just in case anyone pops by:
C:\Windows\ServiceProfiles\LocalService
is the local service profile folder, so it will end up in there.
If you want to debug it surround that line with a try catch, and then write the error to a file:
try
{
Directory.CreateDirectory(Environment.SpecialFolder.LocalApplicationData + "\\MyService");
}
catch (Exception ex)
{
System.IO.StreamWriter file = new System.IO.StreamWriter(#"C:\MyServicelog.txt",true);
file.WriteLine(ex.Message);
file.Close();
}
At least then you can see whats causing the error
Martyn

I suggest you write the exception details to the event log. All user accounts have permission to write to the event log as long as the log and source names have already been created by an administrator (which you can do simply by running the app as yourself first).
As to the root cause of the error, it may be because LocalService doesn't normally get a full set of profile folders created by default. I'm not sure whether this is by design, or simply what I have observed on various machines.

Writing log files

I am developing c# application, which is running as a windows service.
What ever transactions we are doing in the application i am writing it into log file.
A log directory is added in app.config file as below.
<add key ="LogDir" value="log" />
<add key ="LogLevel" value="2" />
And in the c# code the above one is accessing as below.
int logLevel = Convert.ToInt32(ConfigurationManager.AppSettings["logLevel"]);
if (logLevel > 0)
{
logger = new Logger();
logger.TraceLevel = logLevel - 1;
logger.logDir = ConfigurationManager.AppSettings["logDir"];
logger.logFileBaseName = "touchserver";
}
And then when any process is happening i am writing the data to the log as below.
TouchServer.Log(Logger.MessageType.Trace, 1, "Item successfully deleted");
And when i run my application in debug mode (i mean as console application) the log file will be created in the application's debug folder and the data will write into the log file.
But my problem is that when i install my application as service the log file is not getting created in the debug folder, and i am unable to see the actions performed , in case if anything went wrong.
Please help me to find a solution in this.
And i am installing service using Installutil command.
Thanks in advance
sangita

While you could get into why this is not working and fix the solution, overall there is no need to implement a logging component.
There are excellent free libraries available that do this very well. log4net is very popular. It is easy to use, feature rich and efficient. Take a look at it.

But my problem is that when i install my application as service the log file is not getting created in the debug folder, and i am unable to see the actions performed , in case if anything went wrong.
Check out what are the result of the IO operations by using Process Monitor. I suspect you'll find the identity being used to run the service process does not have write permissions where it is trying to write the log file.
But the better option is to use an existing logging library as Hemal suggests.