Visual Studio Web Deploy在发布时不会修改连接字符串

Question

I have a WebApp ASP.Net Core 2.1 contains multiple database connection strings, which are specified into an appsettings.json configuration file. When developing locally, they are set to point a Local Database for debugging purposes.

At Publish Time, those connection strings were modified by the Visual Studio Web Deploy Publisher , in the settings panel as per screenshot below. But, for a few days, those connection strings are no more modified automatically by the publisher , despite check-boxes "Use this connection string at run time" are checked.

This is super painful : the app crashes right after publishing (cannot connect to databases) and I have to go over FTP to change manually those connection strings.

Context of the bug

In the past days, I created a shared appsetting.json file across multiple projects. This shared setting file is referenced as a linked file on every project. On my Web App project, I changed the startup class to embed this additional configuration file into the ConfigurationRoot. Using the default Startup constructor was not embedding this additional setting file.

public class Startup
{           
    //public Startup(IConfiguration configuration)  //Default Startup constructor which DOES not take into account the  sharedappsettings.json configuration file
    //{
    //    Configuration = configuration;
    //}

    public Startup(IHostingEnvironment env)
    {
        var contentRoot = env.ContentRootPath;

            var builder = new ConfigurationBuilder()
                .SetBasePath(contentRoot)
                .AddJsonFile("appSettings.json")
                .AddJsonFile("sharedappSettings.json");
            Configuration = builder.Build();
    }

Questions

• Why the publisher not modify anymore the various connection strings, despite the interface shows that it shall do it?
• How can I override this behavior, and change those connection strings at publish time, outside of the Web Deploy interface if not possible otherwise?

Visual Studio Web Deploy Screenshot

Answer 1

I would look at config transforms: https://docs.microsoft.com/en-us/aspnet/core/host-and-deploy/iis/transform-webconfig?view=aspnetcore-2.2

This allows you to make config changes which extend beyond connection strings for all of the environments in your pipeline.