Grab images as part of update e2e test

There's few ways to make this perfect but I'd recommend using single quotes inside the expression that goes into the shell script:

```shell
echo "MASTER_NAME='${MASTER_NAME}'"
```

Though that's still prone to injection with something like `'; rm -rf /; x='` for MASTER_NAME...

Generating shell scripts is a bad idea in general (do I even need to say it?)