env option parsing changes

[shinybrar]

In previous firefly versions which utilize a bash script entry-point, the following Kubernetes manifest was supported for setting PROPS_FIREFLY_OPTIONS environment variable using bash-specific quoting $'…'

- name: "PROPS_FIREFLY_OPTIONS"
  value: >-
    $'{"tap": <<<<<------- NO LONGER WORKS
        {"additional":
          {"services":[
            {
              "label": "CADC YouCAT",
              "value": "https://ws-uv.canfar.net/youcat",
              "centerWP": "62;-37;EQ_J2000",
              "fovDeg": 10
            }]
        }
      }
    }'

However, in the updated version of firefly, with a python entry-point parsing is handled by the python module shlex.quote, only plain JSON format (without bash-specific quoting) is parsed correctly and does
not interpret the bash-specific $'…' syntax, leading to extra quoting that results in malformed JSON.

- name: "PROPS_FIREFLY_OPTIONS"
  value: >-
    {"tap":  <<<<<------- WORKS AS EXPECTED
        {"additional":
          {"services":[
            {
              "label": "CADC YouCAT",
              "value": "https://ws-uv.canfar.net/youcat",
              "centerWP": "62;-37;EQ_J2000",
              "fovDeg": 10
            }]
        }
      }
    }

Could we update the documentation to inform users of this change? Providing guidance on using the plain JSON format for PROPS_FIREFLY_OPTIONS will help users transition smoothly and avoid any potential issues when upgrading to the new version, e.g. lsst/suit implementation will break with the new release.

[robyww]

We can, but this version is not released yet and Rubin is not even using it. I have not even tried this new stuff in rubin phalanx statefulset.yaml