How EF design-time tooling will work
------------------------------------
# Package structure

```
Microsoft.EntityFrameworkCore.Tools
├── lib
│   ├── netcoreapp1.0
│   |   └── dotnet-ef.dll
|   ├── net451
|   |   └── _._
|   └── netcore50
|       └── _._
└── tools
    ├── EntityFrameworkCore.psm1
    └── net451
    |    └── ef.exe
    └── netstandard1.3
         └── ef.dll

Microsoft.EntityFrameworkCore.*.Design
--> depends on Microsoft.EntityFrameworkCore.Design

Microsoft.EntityFrameworkCore.Design
└── lib
    └── netstandard1.3
        └── Microsoft.EntityFrameworkCore.Design.dll <-- OperationExecutor
```

# What's different
 - Users must have Microsoft.EntityFrameworkCore.*.Design for their provider.
 - PowerShell forwards to ef.exe on desktop.NET
 - .NET Core CLI and PowerShell share the OperationExecutor
 - ef.dll and ef.exe's only dependencies must be the BCL

# How command execution works

## .NET Core CLI on .NET Core projects

```
> dotnet ef $ARGS
  └─ dotnet.exe \
           $NUGET_CACHE/dotnet-ef.dll \
           $ARGS
     |
     |  (Gathers project model info)
     |  (Resolves tool and app dependencies)
     |  (Triggers a build)
     |  (Launches the "inside man")
     |
     └─ dotnet exec \
           --runtimeconfig ef.runtimeconfig.json \
           --depsfile $appname.deps.json \
           $NUGET_CACHE/ef.dll \
           --assembly $full_path_to_appname.dll \
           $ARGS
        |
        |  (Uses command line arguments to identify operation and options)
        |
        └─ OperationExecutor
```

### What's different

 - "dotnet ef" will execute `$NUPKG/tools/netstandard1.3/ef.dll`
instead of `$BUILD_OUTPUT/Microsoft.EntityFrameworkCore.Tools.Cli.dll`.
 - Ms.EF.Tools no longer needs to be in dependencies
 - dotnet-ef.dll will need to resolve a framework to run and produce
   a runtimeconfig.json file

## .NET Core CLI on .NET Core projects

```
> dotnet ef $ARGS
  └─ dotnet.exe \
           $NUGET_CACHE/dotnet-ef.dll \
           $ARGS
     |
     |  (Gathers project model info)
     |  (Resolves tool and app dependencies)
     |  (Triggers a build)
     |  (Launches the "inside man")
     |
     └─ $NUGET_CACHE/ef.exe \
           --config ef.exex.config \
           --assembly $full_path_to_appname.dll \
           $ARGS
        |
        |  (Uses command line arguments to identify operation and options)
        |  (Loads user app in sub app-domain)
        |
        └─ OperationExecutor
```

### What's different

 - "dotnet ef" will execute `$NUPKG/tools/netstandard1.3/ef.dll`
instead of `$BUILD_OUTPUT/Microsoft.EntityFrameworkCore.Tools.Cli.exe`.
 - Ms.EF.Tools no longer needs to be in dependencies in addition to the *.Design assembly


## PowerShell on .NET Framework projects

```
PS > Add-Migration $ARGS
     └─ EntityFrameworkCore.psm1
        |
        |  (Translates cmdlet arguments to dotnet-ef equivalent"
        |
        ├─ "ef.exe $ARGS --json"
        |
        └─ (Parse JSON results and trigger VS window opens)
```

## What's different

 - Powershell cmdlets's only job is to forward to ef.exe and parse json results

## PowerShell on .NET Core projects

```
PS > Add-Migration $ARGS
     └─ EntityFrameworkCore.psm1
        |
        |  (Translates cmdlet arguments to dotnet-ef equivalent"
        |
        ├─ "dotnet ef $ARGS --json"
        |
        └─ (Parse JSON results and trigger VS window opens)
```

## What's different

 - nothing