Support for docker user name and password environmen variables. (mlco…

…mmons#337)

This commit adds capability to provide docker user name and password via two environment variables - `SINGULARITY_DOCKER_USERNAME` and `SINGULARITY_DOCKER_PASSWORD`. If these variables found (when retrieving image manifest), JSON configuration files (such as `~/.docker/config.json`) are not scanned.

runners/mlcube_singularity/mlcube_singularity/singularity_client.py

@@ -1,6 +1,7 @@
 import base64
 import json
 import logging
+import os
 import platform
 import typing as t
 from enum import Enum
@@ -578,21 +579,37 @@ def _get_authentication_token(www_authenticate: t.Optional[str], auth_key: str)
  )
 
  url: t.Optional[str] = parsed.pop("realm", None)
- loggable_url: t.Optional[str] = url
-
- auth_token: t.Optional[str] = _get_auth_token(auth_key)
- if auth_token:
- logger.info("_get_authentication_token using auth token from config file.")
- if url.startswith("https://"):
- url = url[8:]
- loggable_url = f"https://***:***@{url}"
- url = "https://" + base64.b64decode(auth_token).decode() + "@" + url
-
  if not url:
  raise MLCubeError(
  f"_get_authentication_token unrecognized www_authenticate format (www_authenticate={www_authenticate}, "
  f"parsed={parsed})."
  )
+ loggable_url: str = url
+
+ if url.startswith("https://"):
+ url = url[8:]
+
+ if os.environ.get("SINGULARITY_DOCKER_USERNAME", None) and os.environ.get(
+ "SINGULARITY_DOCKER_PASSWORD", None
+ ):
+ logger.info(
+ "_get_authentication_token found docker username (SINGULARITY_DOCKER_USERNAME) and "
+ "password (SINGULARITY_DOCKER_PASSWORD) environment variables."
+ )
+ loggable_url = f"https://***:***@{url}"
+ username, password = (
+ os.environ["SINGULARITY_DOCKER_USERNAME"],
+ os.environ["SINGULARITY_DOCKER_PASSWORD"],
+ )
+ url = f"{username}:{password}@{url}"
+ else:
+ auth_token: t.Optional[str] = _get_auth_token(auth_key)
+ if auth_token:
+ logger.info("_get_authentication_token using auth token from config file.")
+ loggable_url = f"https://***:***@{url}"
+ url = base64.b64decode(auth_token).decode() + "@" + url
+
+ url = f"https://{url}"
  logger.debug(
  "_get_authentication_token requesting token at %s for %s.", loggable_url, parsed
  )