Update initialize-gun.sh script with retries for vault component

Pipeline 503's have been alleviated so that is a lower priority as of now. The retries use the VAULT_RETRIES environment variable so pipeline users can set this env variable to increase the number or retries if necessary.

The initialize-gun.sh script needs a few more retries for the following

• vault login
• root key get
• put targets key

Background

---

Vault will intermittently return 503's when the initialization script is run or the pipeline attempts to log in.

Example of missing the root key

URL: GET https://<root key url>
Code: 503. Raw Message:

upstream connect error or disconnect/reset before headers. reset reason: local reset

and when logging in

Error authenticating: Error making API request.

URL: PUT https://<vault notary admin login>
Code: 503. Raw Message:

upstream connect error or disconnect/reset before headers. reset reason: local reset
Error making API request.

URL: GET https://<root key url>
Code: 400. Errors:

and when pushing the targets key

URL: PUT https://<targets key url>
Code: 503. Raw Message:

upstream connect error or disconnect/reset before headers. reset reason: local reset

This behavior also affects the pipeline

https://repo1.dso.mil/dsop/opensource/mariadb/mariadb103/-/jobs/2637116