I have created an ASP.NET MVC web app which uses an SQLite database under EF6.
The app works fine in VS. The database is included in the project in the App_Data folder. When I publish to Azure (or an IIS test server on the LAN) I get an error. The Azure instance is showing an HTTP 500 error, and it only happens on views which require database access to load. Other than that it works fine. The IIS test server shows an error saying unable to open database file. I tried loosening file permissions on the .db file on the IIS instance, but nothing changed. I'm not sure how to go about doing anything on the Azure instance.
Can someone please assist me with debugging a SQLite connection problem on Azure/IIS?
Details
VS 2015 Enterprise
Azure app services (free tier, production server)
SQLite3 database
IIS on Windows Server 2012R2 (test server)
I have tried all sorts of combinations of connection strings:
setting a connection string to the D:/xxx/xxx path in Azure Portal
modifying the connection string in the deployment profile in VS (replaces value in web.config upon deployment)
just leaving it all the same
Nothing has worked or even changed the error. Perhaps one of those configurations is able to access the file but simply can't open it (which is sort of what the IIS error suggests, I think). Even then, how do I go about finding out?
EDIT
On the IIS test server I discovered that the entire problem was that the connection string in Web.config was wrong. I manually edited it on the server and it fired right up. I'm still not sure how to correct the path on the Azure server, nor how to correct my deployment settings in VS to inject the correct path. Thoughts along those lines are still appreciated.
EDIT 2
I've also found that each time I hit a page requiring DB access, I see this error show up in the application logs on Azure:
2017-01-03T20:25:32
System.ApplicationException: The trace listener AzureBlobTraceListener is disabled. ---> System.InvalidOperationException: The SAS URL for the cloud storage account is not specified. Use the environment variable 'DIAGNOSTICS_AZUREBLOBCONTAINERSASURL' to define it.
at Microsoft.WindowsAzure.WebSites.Diagnostics.AzureBlobTraceListener.RefreshConfig()
--- End of inner exception stack trace ---
After some abysmally slow debugging sessions, I finally remembered that in toying around I had set a connection string value in the Azure portal.
Apparently whatever value is set in the Azure Portal overrides (at runtime?) the values in the Web.config file
I simply deleted the connection string from the Azure Portal (your app/Application Settings/Connection Strings) and it worked. The final connection string looks like this:
<add name="yourThingEntities" connectionString="metadata=res://*/cadb_SQLite.csdl|res://*/cadb_SQLite.ssdl|res://*/cadb_SQLite.msl;provider=System.Data.SQLite.EF6;provider connection string="data source=D:\home\site\wwwroot\App_Data\yourSQLiteDBFile.db"" providerName="System.Data.EntityClient" />
To get the Web Deploy working in VS, you'll need to edit the publish profile to have a connection string matching the format
data source=D:\home\site\wwwroot\App_Data\yourSQLiteDBFile.db
Apparently not many people use SQLite for web apps, and most people should not. If you ever expect more than one user for your website at a time, you shouldn't fix SQLite, you should convert to SQL Server CE or just full-blown SQL Server which Azure will take care of for a paltry $5/mo. Choose wisely!
Related
I am trying to deploy a WCF service that uses a SQLite DB to read some data as well as connecting to another Database (MS SQL). The service itself is consumed by a ASP Web site running on the same server.
The problem is that only my user is able to fully use the website and service. Every other user can't seem to open the sqlite database file.
What kind of permissions or special access do you need to access a sqlite database from IIS?
The Application pool is setup with a domain account so that access to the MS SQL Database can be granted (Integrated Security).
The folder where the database is stored is accessible by the account. And I've even tried to make it accessible by Everyone and all users with no luck.
I feel I'm missing something obvious but I can't figure out what...
Update: The error is as follows:
System.Data.Entity.Core.EntityException
An exception of type 'System.Data.Entity.Core.EntityException' occurred in EntityFramework.dll but was not handled in user code
Additional information: The underlying provider failed on Open.
Inner Exception:
System.Data.SQLite.SQLiteException
Unable to open database file.
I was able to resolve the issue, I'm going to document it here for posterity. I took a few steps to do so, and I currently don't have the environment set up to be able to reproduce the issue consistently and quickly, so I'm not entirely sure which was the actual solution.
Disclaimer aside, here are my changes:
I created a new Application Pool and Website on IIS, on another directory entirely, not on "C:\inetpub\wwwroot". I used "C:\Sites\MySite" to deploy both my WCF service and the website which consumed it.
I changed the application pool identity account to a new AD Service account.
I placed the database inside of the Service Web App directory, within a directory called data. I removed all inherited permissions from the directory and the database file, and gave the both the service account and Everyone Full Control of the directory and database file.
I edited the connection string for sqlite to have the setting "Journal Mode=Off;".
I stopped and started both the Application Pool and the WebSite on IIS.
After this the service worked correctly, and I was able to access both the database file and the connection to SQL Server. If I get the opportunity, I would set up some kind of virtual network to replicate this and see if I could figure out exactly what caused the error in the first place.
I created a simple ASP.Net Core application with user authentication (so all the Entity Framework has been preloaded into the web app template). It is connecting to my database with the connectionString that is located in my appsettings.json file, with "data source = {computerName}\\{serverName}" setup.
The database instance and Visual Studio are located on the same machine. This works fine in returning data to the web api while within development and debugging mode. When I publish it and try to go to the site from a domain name it does allow me to view the webpages that are not needing database connection but the rest that need data from the database returns pages like this:
Error.
An error occurred while processing your request.
Development Mode
Swapping to Development environment will display more detailed information about the error that occurred.
Development environment should not be enabled in deployed
applications, as it can result in sensitive information from
exceptions being displayed to end users. For local debugging,
development environment can be enabled by setting the
ASPNETCORE_ENVIRONMENT environment variable to Development, and
restarting the application.
I have tried to change the Environment Variables for ASPNETCORE_ENVIRONMENT from Development to Production to no success.
I have tried adding appsettings.Production.json to publishOptions in my project.json file, even though there is no file appsettings.Production.json, and this did not help. dotnet publish
Adding the evironment variable in the web.config file did not work Deployment
I need help getting the published web api to connect to my SQL Server database from outside the development Visual Studio setup.
The last thing I can think of is that maybe I am incorrect in how I understand the connection string. If the web api uses the connection string to connect to the database from the server-side then it should work just fine like it does when in development calling to http://localhost:port# since it's all on the same machine. But, if the database string needs to be based on a client-side call then it would have to be with domain names and IP addresses.
Can someone tell me which one it is?
The only thing else that comes to mind is that there is something I am not doing, and need to do, inside of IIS Manager. I see connect string there as well but unsure what that is for our does since the connection string is inside the application. Also maybe I am suppose to give the app some kind of authorization to communicate with the database server even though they are on the same machine???
After much research, finally googling "how to deploy a web api in iis" I was able to learn from Host ASP.NET Web API in IIS using Visual Studio Publish that I needed to add the security entity BUILTIN\IIS_IUSRS. Then placing a mapping to my database tables and giving db_datareader (and possibly db_datawriter) for the database to the IUSER to allow access from my self hosted IIS web api. This from the above mentioned link with the part stating
Accessing Database under IIS APPPOOL\ASP.NET v4.0
As we are using ASP.NET v4.0 App Pool make sure IIS APPPOOL\ASP.NET v4.0 is added to your Database Server -> Security -> Logins.
my asp.net application runs successfully in development server of visual studio. but when i deploy my application in IIS it generates the error as follows
Failed to generate a user instance of SQL Server due to failure in
retrieving the user's local application data path. Please make sure
the user has a local user profile on the computer. The connection will
be closed.
what are the necessary changes that i should do in my application. also guide me how to deploy my database on IIS.
What is your connection string?
More specifically, I am wondering if you are using a .mdf file as your database.
If this is the case, you need to ensure that your web application has write-permissions within the App_Data folder of your website.
It is hard to say exactly without seeing your connection string, but possibly this KB article will help. It relates to SQLExpress and the error you are seeing.
http://support.microsoft.com/kb/2002980
I'm developing an ASP.NET web app that needs to access an SQL Server database. The server the app needs to run on is running Windows Server 2000, SQL server 2000, IIS6, and .NET 2.0.
If I run the web app on my machine with Visual Web Developer 2010 with the testing webserver in Visual studio, but accessing the database on the actual web server, it works fine. However, If I put this app on the actual webserver, and try to access it through the browser, I get a permissions errors saying I don't have access to those tables.
There are two tables my app needs to access. On one of them I changed the permissions with SQL Management Studio to allow the public group select permissions, and that solved the problem. On the other table (very large table) I tried to do the same, but got an error saying it timed out waiting to get a lock on the table. Is there a way to change this timeout or another way to change the permissions?
I don't believe I should even have to change the permissions though, because there are classic ASP apps on that server that access the very same tables. I think the issue is the user that is being used to access the tables. If I can access the tables running the web app from my machine, and classic ASP apps on the server can access them, but my ASP.NET app can't, my ASP.NET app must be using a different user account. How can I check this and make the necessary changes?
Regarding your permission error, it's probably because on your machine the app is accessing the database with your permissions, with windows integrated login.
Normally, a web application is supposed to access a database using a technical user, that is specified in the web.config file, in the connection strings section. It's something like
<configuration>
<connectionStrings>
<add name="myConnsStr" connectionString="server=myserver.example.com;database=mydatabase;uid=tech_account;pwd=tech_account_password" providerName="System.Data.SqlClient" />
</connectionStrings>
...
</configuration>
How does yours look like?
For the other one, yes, do the permission change in T-SQL. If you are not sure how to do that, do the change in the designer, then before clicking OK, use the Script button in the header area. Script the change to the clipboard and then try to run in a new query window. You can play with the query timeouts in the options dialog.
You could try setting the lock timeout to -1 (meaning it'll never timeout)
SET LOCK_TIMEOUT -1
GO
And you can also try adding the permissions using a query
sp_addrolemember #rolename = 'db_datareader', #membername = 'YourAspApp'
You can also try to change your asp.net user in the asp.net connection string to a user which already has selecting privileges.
Let me know if any of that worked, it's a good place to start with =)
I'm stumped. I have a client site on a virtual private server - Windows Web Server 2008 SP2, IIS7, SQL Server 2008 Express.
I'm trying to setup a second web application, to allow him to review updates prior to their going live. I've created the web application in IIS7, and I have added a second database to SQL Server. The second db is essentially a copy of the production db, with 'DEV' prefixed to the database name and a few new fields in a few tables.
My production site works fine. However, the test site comes back with an SqlException: "Invalid column name 'version'." This is one of the new fields - which leads me to believe that my dev site is referring to the production database, and not the dev database. Connection strings, however, do point to different databases (although the login is the same for both):
Production site: "Server=.\SQLExpress;Database=myDbName;User ID=myUserName;Password=myUserPassword;"
Dev site: "Server=.\SQLExpress;Database=DEVmyDbName;User ID=myUserName;Password=myUserPassword;"
Seems like this should be something obvious that I'm missing. A colleague suggested that I create another application pool for the second IIS application, but it does not seem to have helped.
UPDATE, following further testing:
I changed the dev site's connection string to
"Server=.\SQLExpress;Database=DEVmyDbName;User ID=devuser;Password=myNewDifferentPassword;"
and created a new SQL server login on the database, and only gave it access to the dev database. I also set the dev database as the account's default database. I removed access to the dev database from the production login. When I try to login to the site, I get the following error:
The server principal "devuser" is not able to access the database "myDbName" under the current security context.
As a result, there are two things I know for certain:
Since it's using the new username to login, I know the app is using the connection string I'm feeding it;
For some reason, once logged in, it appears to be ignoring the specified database and trying to use the production database instead.
I don't think it should make a difference, but I will mention I'm using NHibernate for database access.
Still stumped.
It turns out that NHibernate was significant. One of the NHibernate configuration options that was set was "default_schema" - when I removed it, the app started connecting to the correct database.
It appears that the default_schema property was overriding whatever database was specified in the connection string.