Microsoft.AspNetCore.App 2.2.7 not found in Docker image built from project using Paket

Question

I have a docker image built from an F# project that uses Paket. At run time the image fails with:

It was not possible to find any compatible framework version The specified framework 'Microsoft.AspNetCore.App', version '2.2.7' was not found.

My dockerfile looks like this:

# Two stage build because Paket means project files reference external files
# via <Import Project="..\.paket\Paket.Restore.targets" />
# https://github.com/fsprojects/Paket/issues/3006#issuecomment-359750323

FROM microsoft/dotnet:2.2-sdk-alpine AS build
RUN apk update \
    && apk add --no-cache bash
WORKDIR /app

# copy fsproj and restore as distinct layers
COPY MyCompany.WebApi/MyCompany.WebApi.fsproj ./MyCompany.WebApi/
COPY NuGet.config ./

RUN dotnet restore MyCompany.WebApi/MyCompany.WebApi.fsproj --configfile NuGet.config

# copy everything else and build
COPY . ./
RUN dotnet publish MyCompany.WebApi/MyCompany.WebApi.fsproj -c Release -o out

# build runtime image
FROM microsoft/dotnet:2.2-sdk-alpine AS final
RUN apk update \
    && apk add --no-cache bash
WORKDIR /app
COPY --from=build /app/MyCompany.WebApi/out ./

ENTRYPOINT ["dotnet", "MyCompany.WebApi.dll"]

Same problem occurs if I use 2.2-runtime-alpine as the basis for final.

My packet.lock includes these lines:

// https://github.com/fsharp/FAKE/issues/2193:
version 5.216.0
...
source https://api.nuget.org/v3/index.json
...
nuget Microsoft.AspNetCore.App
...

I notice that my generated paket.dependencies specifies a particular version of Microsoft.AspNetCore.App:

Microsoft.AspNetCore.App (2.2.7)
  Microsoft.AspNet.WebApi.Client (>= 5.2.6 < 5.3) - restriction: >= netcoreapp2.2
  Microsoft.AspNetCore (>= 2.2 < 2.3) - restriction: >= netcoreapp2.2
  Microsoft.AspNetCore.Antiforgery (>= 2.2 < 2.3) - restriction: >= netcoreapp2.2

...although it looks like we are discouraged from specifying versions:

https://learn.microsoft.com/en-us/aspnet/core/fundamentals/metapackage-app?view=aspnetcore-2.2

So my question is: is it possible to come up with a combination of Docker, Paket, F# and AspNetCore that works together?

Edit: paket.dependencies -> packet.lock

Edit 2: Here's a listing of the entry point's directory and below:

.:
total 18668
-rwxr--r--    1 root     root        190976 Aug 29 13:18 Dapper.dll
-rwxr--r--    1 root     root       2850168 Aug  2 19:03 FSharp.Core.dll
-rwxr--r--    1 root     root        243200 Apr 16 08:00 Fable.Core.dll
-rwxr--r--    1 root     root        342528 Feb 10  2019 Giraffe.dll
...lots more DLLs from Nuget dependencies
... some DLLs from our internal dependencies
-rw-r--r--    1 root     root        100670 Sep 12 13:23 MyCompany.WebApi.deps.json
-rwxr-xr-x    1 root     root         61440 Sep 12 13:23 MyCompany.WebApi.dll
-rw-r--r--    1 root     root         10608 Sep 12 13:23 MyCompany.WebApi.pdb
-rw-r--r--    1 root     root           149 Sep 12 13:23 MyCompany.WebApi.runtimeconfig.json
-rwxr--r--    1 root     root        178824 Nov 28  2018 System.Net.Http.Formatting.dll
-rwxr--r--    1 root     root         23088 Sep 18  2018 System.Runtime.CompilerServices.Unsafe.dll
-rwxr--r--    1 root     root         29744 Feb 15  2019 System.Security.Cryptography.OpenSsl.dll
-rwxr--r--    1 root     root        189168 Nov 29  2018 System.Security.Cryptography.Pkcs.dll
-rwxr--r--    1 root     root         29760 Jul 19  2018 System.ServiceModel.Primitives.dll
-rwxr--r--    1 root     root         30784 Jul 19  2018 System.ServiceModel.dll
-rwxr--r--    1 root     root        759024 Nov 29  2018 System.Text.Encoding.CodePages.dll
-rwxr--r--    1 root     root         91136 Sep 16  2018 TaskBuilder.fs.dll
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 cs
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 de
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 es
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 fr
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 it
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 ja
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 ko
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 pl
-rwxr--r--    1 root     root        277504 Aug 30  2018 protobuf-net.dll
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 pt-BR
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 ru
drwxr-xr-x    4 root     root          4096 Sep 12 13:23 runtimes
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 tr
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 zh-Hans
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 zh-Hant

./cs:
total 376
-rwxr--r--    1 root     root         33144 Aug  2 19:03 FSharp.Core.resources.dll
-rwxr--r--    1 root     root        308088 Aug  8 16:19 Microsoft.CodeAnalysis.CSharp.resources.dll
-rwxr--r--    1 root     root         34896 Aug  8 16:18 Microsoft.CodeAnalysis.resources.dll

./de:
total 392
-rwxr--r--    1 root     root         34168 Aug  2 19:03 FSharp.Core.resources.dll
-rwxr--r--    1 root     root        327544 Aug  8 16:19 Microsoft.CodeAnalysis.CSharp.resources.dll
-rwxr--r--    1 root     root         36216 Aug  8 16:18 Microsoft.CodeAnalysis.resources.dll

./es:
total 388
-rwxr--r--    1 root     root         33360 Aug  2 19:03 FSharp.Core.resources.dll
-rwxr--r--    1 root     root        321104 Aug  8 16:19 Microsoft.CodeAnalysis.CSharp.resources.dll
-rwxr--r--    1 root     root         35920 Aug  8 16:18 Microsoft.CodeAnalysis.resources.dll

./fr:
total 392
-rwxr--r--    1 root     root         33656 Aug  2 19:03 FSharp.Core.resources.dll
-rwxr--r--    1 root     root        327544 Aug  8 16:19 Microsoft.CodeAnalysis.CSharp.resources.dll
-rwxr--r--    1 root     root         36432 Aug  8 16:18 Microsoft.CodeAnalysis.resources.dll

./it:
total 392
-rwxr--r--    1 root     root         33144 Aug  2 19:03 FSharp.Core.resources.dll
-rwxr--r--    1 root     root        325496 Aug  8 16:19 Microsoft.CodeAnalysis.CSharp.resources.dll
-rwxr--r--    1 root     root         36216 Aug  8 16:18 Microsoft.CodeAnalysis.resources.dll

./ja:
total 428
-rwxr--r--    1 root     root         35704 Aug  2 19:03 FSharp.Core.resources.dll
-rwxr--r--    1 root     root        358776 Aug  8 16:19 Microsoft.CodeAnalysis.CSharp.resources.dll
-rwxr--r--    1 root     root         38264 Aug  8 16:18 Microsoft.CodeAnalysis.resources.dll

./ko:
total 396
-rwxr--r--    1 root     root         34680 Aug  2 19:03 FSharp.Core.resources.dll
-rwxr--r--    1 root     root        331336 Aug  8 16:19 Microsoft.CodeAnalysis.CSharp.resources.dll
-rwxr--r--    1 root     root         36728 Aug  8 16:18 Microsoft.CodeAnalysis.resources.dll

./pl:
total 396
-rwxr--r--    1 root     root         34168 Aug  2 19:03 FSharp.Core.resources.dll
-rwxr--r--    1 root     root        331128 Aug  8 16:19 Microsoft.CodeAnalysis.CSharp.resources.dll
-rwxr--r--    1 root     root         36216 Aug  8 16:18 Microsoft.CodeAnalysis.resources.dll

./pt-BR:
total 380
-rwxr--r--    1 root     root         32632 Aug  2 19:03 FSharp.Core.resources.dll
-rwxr--r--    1 root     root        316280 Aug  8 16:19 Microsoft.CodeAnalysis.CSharp.resources.dll
-rwxr--r--    1 root     root         35704 Aug  8 16:18 Microsoft.CodeAnalysis.resources.dll

./ru:
total 508
-rwxr--r--    1 root     root         39800 Aug  2 19:03 FSharp.Core.resources.dll
-rwxr--r--    1 root     root        430968 Aug  8 16:19 Microsoft.CodeAnalysis.CSharp.resources.dll
-rwxr--r--    1 root     root         42360 Aug  8 16:18 Microsoft.CodeAnalysis.resources.dll

./runtimes:
total 8
drwxr-xr-x    3 root     root          4096 Sep 12 13:23 unix
drwxr-xr-x    3 root     root          4096 Sep 12 13:23 win

./runtimes/unix:
total 4
drwxr-xr-x    4 root     root          4096 Sep 12 13:23 lib

./runtimes/unix/lib:
total 8
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 netcoreapp2.1
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 netstandard2.0

./runtimes/unix/lib/netcoreapp2.1:
total 88
-rwxr--r--    1 root     root         86280 Feb 15  2019 System.Security.Cryptography.OpenSsl.dll

./runtimes/unix/lib/netstandard2.0:
total 1848
-rwxr--r--    1 root     root       1889344 Jul 19  2018 System.Private.ServiceModel.dll

./runtimes/win:
total 4
drwxr-xr-x    5 root     root          4096 Sep 12 13:23 lib

./runtimes/win/lib:
total 12
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 netcoreapp2.0
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 netcoreapp2.1
drwxr-xr-x    2 root     root          4096 Sep 12 13:23 netstandard2.0

./runtimes/win/lib/netcoreapp2.0:
total 744
-rwxr--r--    1 root     root        761392 Nov 29  2018 System.Text.Encoding.CodePages.dll

./runtimes/win/lib/netcoreapp2.1:
total 212
-rwxr--r--    1 root     root        214064 Nov 29  2018 System.Security.Cryptography.Pkcs.dll

./runtimes/win/lib/netstandard2.0:
total 1848
-rwxr--r--    1 root     root       1889344 Jul 19  2018 System.Private.ServiceModel.dll

./tr:
total 376
-rwxr--r--    1 root     root         32632 Aug  2 19:03 FSharp.Core.resources.dll
-rwxr--r--    1 root     root        312184 Aug  8 16:19 Microsoft.CodeAnalysis.CSharp.resources.dll
-rwxr--r--    1 root     root         35192 Aug  8 16:18 Microsoft.CodeAnalysis.resources.dll

./zh-Hans:
total 344
-rwxr--r--    1 root     root         31096 Aug  2 19:03 FSharp.Core.resources.dll
-rwxr--r--    1 root     root        278904 Aug  8 16:19 Microsoft.CodeAnalysis.CSharp.resources.dll
-rwxr--r--    1 root     root         33144 Aug  8 16:18 Microsoft.CodeAnalysis.resources.dll

./zh-Hant:
total 344
-rwxr--r--    1 root     root         30584 Aug  2 19:03 FSharp.Core.resources.dll
-rwxr--r--    1 root     root        280144 Aug  8 16:19 Microsoft.CodeAnalysis.CSharp.resources.dll
-rwxr--r--    1 root     root         33360 Aug  8 16:18 Microsoft.CodeAnalysis.resources.dll

Answer 1

I think I've fixed this. Changed the base image to one I found referenced in a Microsoft tutorial, and removed the apk update stage (as this returned a non-zero exit code with this new base image). So this is my dockerfile now.

FROM mcr.microsoft.com/dotnet/core/sdk:2.2 AS build
WORKDIR /app

# copy fsproj and restore as distinct layers
COPY MyCompany.WebApi/MyCompany.WebApi.fsproj ./MyCompany.WebApi/
COPY NuGet.config ./

RUN dotnet restore MyCompany.WebApi/MyCompany.WebApi.fsproj --configfile NuGet.config

# copy everything else and build
COPY . ./
RUN dotnet publish MyCompany.WebApi/MyCompany.WebApi.fsproj -c Release -o out

# build runtime image
FROM mcr.microsoft.com/dotnet/core/aspnet:2.2 AS final
WORKDIR /app
COPY --from=build /app/MyCompany.WebApi/out ./

ENTRYPOINT ["dotnet", "MyCompany.WebApi.dll"]

It starts up OK now, haven't yet tested the functionality!

I am far from a Docker or Linux expert, but I would hazard a guess that the Alpine image hasn't caught up with the latest dotnet releases. I would also guess that the image I create after this change is fatter than it needs to be, but I'll take 'fat and working' for now.