Add Net5.0 for OTLP Integration test (#1802)

.github/workflows/integration.yml

@@ -49,7 +49,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        version: [netcoreapp2.1,netcoreapp3.1]
+        version: [netcoreapp2.1,netcoreapp3.1,net5.0]
     steps:
       - uses: actions/checkout@v2
       - name: Run OTLP Exporter docker-compose.integration

test/OpenTelemetry.Exporter.OpenTelemetryProtocol.Tests/Dockerfile

@@ -2,16 +2,16 @@
 # This should be run from the root of the repo:
 # docker build --file test/OpenTelemetry.Exporter.OpenTelemetryProtocol.Tests/Dockerfile
 
-ARG SDK_VERSION=3.1
-FROM mcr.microsoft.com/dotnet/core/sdk:${SDK_VERSION} AS build
+ARG SDK_VERSION=5.0
+FROM mcr.microsoft.com/dotnet/sdk:5.0-focal AS build
 ARG PUBLISH_CONFIGURATION=Release
-ARG PUBLISH_FRAMEWORK=netcoreapp3.1
+ARG PUBLISH_FRAMEWORK=net5.0
 WORKDIR /repo
 COPY . ./
 WORKDIR "/repo/test/OpenTelemetry.Exporter.OpenTelemetryProtocol.Tests"
 RUN dotnet publish "OpenTelemetry.Exporter.OpenTelemetryProtocol.Tests.csproj" -c "${PUBLISH_CONFIGURATION}" -f "${PUBLISH_FRAMEWORK}" -o /drop -p:IntegrationBuild=true -p:TARGET_FRAMEWORK=${PUBLISH_FRAMEWORK}
 
-FROM mcr.microsoft.com/dotnet/core/sdk:${SDK_VERSION} AS final
+FROM mcr.microsoft.com/dotnet/sdk:${SDK_VERSION} AS final
 WORKDIR /test
 COPY --from=build /drop .
 ENTRYPOINT ["dotnet", "vstest", "OpenTelemetry.Exporter.OpenTelemetryProtocol.Tests.dll"]