Terraform for each conditionals

s3-bulk-upload.tf

# This is an example to bulk upload files to S3
#   A local source directory and sample pattern are provided as variables.
#   All matching files are uploaded to S3

locals {
  file_list = toset(fileset(var.source_path, var.source_file_pattern))

  # If you use terragrunt, use this local block instead to ignore 
  #  the .terragrunt-source-manifest file it adds to each directory.
  # This is useful if there is no common pattern to files.
  file_list = toset([for k in toset(fileset(var.source_path, var.source_file_pattern)) : k if length(regexall(".*terragrunt.*", k)) == 0])
}
  
variable "s3_bucket" {
  description = "S3 bucket to upload the files to"
}
variable "s3_key" {
  description = "Sub-directory on S3 to upload the files to"
}
variable "source_path" {
  description = "Source directory on local to watch for files to upload"
}
variable "source_file_pattern" {
  description = "Pattern to match for files"
}
  
resource "aws_s3_bucket_object" "this" {
  for_each = local.file_list
  bucket   = var.s3_bucket
  key      = format("%s/%s", var.s3_key, each.key)
  source   = format("%s/%s", var.source_path, each.key)
  etag     = filemd5(format("%s/%s", var.source_path, each.key))
}

  

s3-upload.tf

# This is an example to upload files to S3 "conditionally"
#   A list of files is in the local variable files_list.
#   If the file exists on disk, it's uploaded, otherwise 
#    terraform skips to the next item in files_list.

locals {
  files_list = toset(["file1.txt", "file2.txt", "file3.txt"])
}

variable "s3_bucket" {
  description = "S3 bucket to upload the files to"
}
variable "s3_key" {
  description = "Sub-directory on S3 to upload the files to"
}
variable "source_path" {
  description = "Source directory on local to watch for files to upload"
}

resource "aws_s3_bucket_object" "this" {
  for_each = toset([for k in local.files_list : k if fileexists("${path.module}/${k}")])
  bucket   = var.s3_bucket
  key      = format("%s/%s", var.s3_key, each.key)
  source   = format("%s/%s", var.source_path, each.key)
  etag     = filemd5(format("%s/%s", var.source_path, each.key))
}