Use s3 relative path in cloudformation - aws-cloudformation

Question

I would like to access supporting files of cloud formation from s3 using a relative path from where the template is
I felt like I need to use AWS::Include Transform and CodeUri together to achieve this but I am not sure how to do the same
Right now in cloudformation init am using
Below is the sample command
"1_Step1": {
"command": {
"Fn::Join": [
"",
[
"powershell.exe -NoProfile -ExecutionPolicy ByPass -command \"& { &'C:\\ step1.ps1'", -> ec2 internal path
" bucketname-v/sub-version/dev/Artifacts” -> s3 folder full path
]
]
}
}
and I need somthing like
"1_Step1": {
"command": {
"Fn::Join": [
"",
[
"powershell.exe -NoProfile -ExecutionPolicy ByPass -command \"& { &'C:\\ extractDevopsInstaller.ps1'", -> ec2 internal path
" /Artifacts” -> s3 folder relative path ‘base of cloud formation template path from s3 ‘
]
]
}
}

Answer 1

It seems as if you're looking for the Fn::Split and Fn::Select intrinsic function.
e.g.:
Resources:
Foobar:
Type: Some::Resource::Type
Properties:
MyProperty: !Join
- /
- - C:\something
- !Select
- 1
- !Split
- /
- some/awesome/path/to/my/template
or in JSON:
"Resources": {
"Foobar": {
"Type": "Some::Resource::Type",
"Properties": {
"MyProperty": {
"Fn::Join": [
"/",
[
"C:\something",
{
"Fn::Select": [
1,
{
"Fn::Split": [
"/",
"some/awesome/path/to/my/template"
]
}
]
}
]
]
}
}
}
}
}```