File Resolver

A Sceptre resolver to get file contents. The returned value can be passed into a parameter as a string, json, or yaml object. The file extension determines the return type. By default, contents from any files that do not end in .json or .yaml will be passed in as a string.

Motivation

Unlike the file_contents resolver which can only pass strings to parameters this resolver can also pass file content in as json and yaml object. This resolver can also resolve remote file contents from the web.

Syntax

parameters|sceptre_user_data:
  <name>: !file /path/to/local/file

parameters|sceptre_user_data:
  <name>: !file URL/To/File

Examples

Local file

text

Get file content and pass it to the parameter as a text string:

tags/departments.txt

"HR, Governance, Engineering, Marketing"

parameters:
  departments: !file tags/departments.txt

json

Get file contents and pass it to the parameter as a json object:

tags/departments.json

[
  "HR",
  "Governance",
  "Engineering",
  "Marketing"
]

parameters:
  departments: !file tags/departments.json

yaml

Get file contents and pass it to the sceptre_user_data as a yaml object:

tags/departments.yaml

- "HR"
- "Governance"
- "Engineering"
- "Marketing"

sceptre_user_data:
  departments: !file tags/departments.yaml

Note: will do the same for files with .yml extension.

Remote file

Works similarly to local file except this will get file contents from the web.

URL

Get file contents from a URL reference:

sceptre_user_data:
  departments: !file https://my-bucket.s3.us-east-1.amazonaws.com/tags/departments.json