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ASP.NET Core hosted Blazor app fails to run in Docker
See original GitHub issueRepro steps:
- Create a new Blazor (ASP.NET Core hosted) app with the Preview 4 bits
- Build and run - it works
- Right click, Add Docker support (Linux)
- Build and run on Docker Linux
Actual result:
Unhandled Exception: System.ArgumentException: The directory name is invalid.
Parameter name: path
at System.IO.FileSystemWatcher.CheckPathValidity(String path)
at System.IO.FileSystemWatcher..ctor(String path)
at Microsoft.AspNetCore.Builder.AutoRebuildExtensions.WatchFileSystem(BlazorConfig config, Action onWrite)
at Microsoft.AspNetCore.Builder.BlazorApplicationBuilderExtensions.UseBlazor(IApplicationBuilder app, BlazorOptions options)
at BlazorDocker.Server.Startup.Configure(IApplicationBuilder app, IWebHostEnvironment env) in C:\Users\daroth\Source\Repos\BlazorDocker\BlazorDocker.Server\Startup.cs:line 43
--- End of stack trace from previous location where exception was thrown ---
at Microsoft.AspNetCore.Hosting.Internal.ConventionBasedStartup.Configure(IApplicationBuilder app)
at Microsoft.AspNetCore.Mvc.Filters.MiddlewareFilterBuilderStartupFilter.<>c__DisplayClass0_0.<Configure>g__MiddlewareFilterBuilder|0(IApplicationBuilder builder)
at Microsoft.AspNetCore.HostFilteringStartupFilter.<>c__DisplayClass0_0.<Configure>b__0(IApplicationBuilder app)
at Microsoft.AspNetCore.Hosting.Internal.WebHost.BuildApplication()
at Microsoft.AspNetCore.Hosting.Internal.WebHost.StartAsync(CancellationToken cancellationToken)
at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token, String startupMessage)
at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token, String startupMessage)
at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token)
at Microsoft.AspNetCore.Hosting.WebHostExtensions.Run(IWebHost host)
at BlazorDocker.Server.Program.Main(String[] args) in C:\Users\daroth\Source\Repos\BlazorDocker\BlazorDocker.Server\Program.cs:line 11
More repro steps:
- Disable Blazor auto-build by adding
<BlazorRebuildOnFileChange>false</BlazorRebuildOnFileChange>to the client project file. - Build and run the app
Actual result:
Unhandled Exception: System.ArgumentException: The path must be absolute.
at Microsoft.Extensions.FileProviders.PhysicalFileProvider..ctor(String root, ExclusionFilters filters)
Parameter name: root
at Microsoft.AspNetCore.Builder.BlazorApplicationBuilderExtensions.UseBlazor(IApplicationBuilder app, BlazorOptions options)
at Microsoft.Extensions.FileProviders.PhysicalFileProvider..ctor(String root, ExclusionFilters filters)
at BlazorDocker.Server.Startup.Configure(IApplicationBuilder app, IWebHostEnvironment env) in C:\Users\daroth\Source\Repos\BlazorDocker\BlazorDocker.Server\Startup.cs:line 43
at Microsoft.AspNetCore.Builder.BlazorApplicationBuilderExtensions.UseBlazor(IApplicationBuilder app, BlazorOptions options)
--- End of stack trace from previous location where exception was thrown ---
at BlazorDocker.Server.Startup.Configure(IApplicationBuilder app, IWebHostEnvironment env) in C:\Users\daroth\Source\Repos\BlazorDocker\BlazorDocker.Server\Startup.cs:line 43
at Microsoft.AspNetCore.Hosting.Internal.ConventionBasedStartup.Configure(IApplicationBuilder app)
--- End of stack trace from previous location where exception was thrown ---
at Microsoft.AspNetCore.Mvc.Filters.MiddlewareFilterBuilderStartupFilter.<>c__DisplayClass0_0.<Configure>g__MiddlewareFilterBuilder|0(IApplicationBuilder builder)
at Microsoft.AspNetCore.Hosting.Internal.ConventionBasedStartup.Configure(IApplicationBuilder app)
at Microsoft.AspNetCore.HostFilteringStartupFilter.<>c__DisplayClass0_0.<Configure>b__0(IApplicationBuilder app)
at Microsoft.AspNetCore.Mvc.Filters.MiddlewareFilterBuilderStartupFilter.<>c__DisplayClass0_0.<Configure>g__MiddlewareFilterBuilder|0(IApplicationBuilder builder)
at Microsoft.AspNetCore.HostFilteringStartupFilter.<>c__DisplayClass0_0.<Configure>b__0(IApplicationBuilder app)
at Microsoft.AspNetCore.Hosting.Internal.WebHost.BuildApplication()
at Microsoft.AspNetCore.Hosting.Internal.WebHost.BuildApplication()
[41m[1m[37mcrit[39m[22m[49m: Microsoft.AspNetCore.Hosting.Internal.WebHost[6]
at Microsoft.AspNetCore.Hosting.Internal.WebHost.StartAsync(CancellationToken cancellationToken)
Application startup exception
at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token, String startupMessage)
System.ArgumentException: The path must be absolute.
Parameter name: root
at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token, String startupMessage)
at Microsoft.Extensions.FileProviders.PhysicalFileProvider..ctor(String root, ExclusionFilters filters)
at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token)
at Microsoft.AspNetCore.Builder.BlazorApplicationBuilderExtensions.UseBlazor(IApplicationBuilder app, BlazorOptions options)
at Microsoft.AspNetCore.Hosting.WebHostExtensions.Run(IWebHost host)
at BlazorDocker.Server.Program.Main(String[] args) in C:\Users\daroth\Source\Repos\BlazorDocker\BlazorDocker.Server\Program.cs:line 11
at BlazorDocker.Server.Startup.Configure(IApplicationBuilder app, IWebHostEnvironment env) in C:\Users\daroth\Source\Repos\BlazorDocker\BlazorDocker.Server\Startup.cs:line 43
--- End of stack trace from previous location where exception was thrown ---
at Microsoft.AspNetCore.Hosting.Internal.ConventionBasedStartup.Configure(IApplicationBuilder app)
at Microsoft.AspNetCore.Mvc.Filters.MiddlewareFilterBuilderStartupFilter.<>c__DisplayClass0_0.<Configure>g__MiddlewareFilterBuilder|0(IApplicationBuilder builder)
at Microsoft.AspNetCore.HostFilteringStartupFilter.<>c__DisplayClass0_0.<Configure>b__0(IApplicationBuilder app)
at Microsoft.AspNetCore.Hosting.Internal.WebHost.BuildApplication()
Issue Analytics
- State:
- Created 4 years ago
- Comments:19 (6 by maintainers)
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This will be fixed soon.
@RealTadango In my case, this was happening because we were calling “UseContentRoot” in a way that could cause it to be something other than the location of our assembly. Changing it to:
seems to help.