Add ability to set SBEDP image by envar, sets default to "latest"

Author: DocOtak

docs/running.md

@@ -28,6 +28,18 @@ It is always safe to interrupt/kill the python process with a {kbd}`control` + {
 There is significant caching of intermediate results and the QA process should quickly catch up to where it left off.
 :::
 
+### ENVVARs
+#### `R2R_CTD_SBEDP_IMAGE`
+The image config can also be controlled via the `R2R_CTD_SBEDP_IMAGE` envvar for using a specific version or for local testing:
+To use a previous version of the published image you could run the command:
+```
+R2R_CTD_SBEDP_IMAGE="ghcr.io/cchdo/sbedp:v2025.07.1" uvx r2r-ctd qa
+```
+or if using a locally built image tag ("testbuild" in this example):
+```
+R2R_CTD_SBEDP_IMAGE="testbuild" uvx r2r-ctd qa
+```
+
 ### Switches
 #### Quiet `-q`
 The verbosity of the logging can be controlled by adding one or more `-q` flags after the `r2r-ctd` but _before_ the `qa` subcommand.

src/r2r_ctd/docker_ctl.py

@@ -42,6 +42,7 @@
 from collections.abc import Mapping
 from functools import wraps
 from logging import getLogger
+from os import environ
 from pathlib import Path
 from tempfile import TemporaryDirectory
 from typing import cast
@@ -58,7 +59,9 @@
 from r2r_ctd.sbe import batch
 from r2r_ctd.state import NamedBytes
 
-SBEDP_IMAGE = "ghcr.io/cchdo/sbedp:v2025.07.1"
+DEFAULT_SBEDP_IMAGE = "ghcr.io/cchdo/sbedp:latest"
+SBEDP_IMAGE = environ.get("R2R_CTD_SBEDP_IMAGE", DEFAULT_SBEDP_IMAGE)
+
 """The current image that will be downloaded/used for the processing"""
 
 logger = getLogger(__name__)