Add support for custom prefixing of JSON parsed secrets

[jromero-pg]

---

NOTE:

This change is intended to be contributed upstream.

• Add support for custom prefixing of JSON parsed secrets aws-actions/aws-secretsmanager-get-secrets#16

---

Summary

Add support for custom prefixing of JSON-parsed secrets.

In our particular case, we needed to disable prefixing. This was achieved by implementing custom prefixing and supporting "empty" prefixes.

Details

From the updated README:

---

Example 4: Parsed JSON in secret with custom prefix

The following example creates environment variables by parsing the JSON in the secret and prefixes them based on provided prefix.
​

- name: Get Secrets by Name and by ARN
  uses: aws-actions/aws-secretsmanager-get-secrets@v1
  with:
    secret-ids: |
      CUSTOM,test/secret
    parse-json-secrets: true

The secret test/secret has the following secret value.
​

{
  "api_user": "user",
  "api_key": "key",
  "config": {
    "active": "true"
  }
}

Environment variables created:
​

CUSTOM_API_USER: "user"
CUSTOM_API_KEY: "key"
CUSTOM_CONFIG_ACTIVE: "true"

Pro-tip: It's possible remove prefixes by providing an "empty" prefix:

- name: Get Secrets by Name and by ARN
  uses: aws-actions/aws-secretsmanager-get-secrets@v1
  with:
    secret-ids: |
      ,test/secret
    parse-json-secrets: true

[tedparagon]

LGTM!