acr-build to support Date as a build-arg

[SteveLasker]

Would like to use various date formats in build args, or for image tags

az acr build-task create \
  -n myBuildTask \
  --context https://github.com/demo42/deploy \
  -t baseimages/microsoft/dotnet-sdk:linux-2.1 \
  --build-arg IMAGE_BUILD_DATE=`date +%Y%m%d-%H%M%S` 

[ehotinger]

Azure/acr-builder#159
Azure/acr-builder#162

https://github.com/Masterminds/sprig/blob/master/docs/date.md

[sajayantony]

@ehotinger - has this been deployed already?

[ehotinger]

@sajayantony nope, deploy to dogfood this Thursday.

[ehotinger]

@SteveLas + @sajayantony FYI this change is globally available as of last Friday ({{.Build.Date}}). However, it should be noted that we're actively changing this to .Run.Date, so nobody should keep a dependency on .Build.Date, and this isn't available for Windows builds.

[SteveLasker]

Thanks Eric, good to know about the change to Run.

[sajayantony]

Closing since we are moving to tasks