Our ImageResizer implementation utilizes Azure Blob Storage and Azure CDN. It works well with the exception of the cache headers. If we're accessing a modified image, such as adding width=100, then the cache-control header is "public" with the expected Expires tag and value. If there is no modification and we use the base URL the cache-control header is set to "private".
This is causing issues with our CDN and site speeds. How do we ensure the base URL also returns cache-control="public" with an expires tag (and also ETag, etc)?
ok, I think I figured this out... or at least it's a workaround. In the AzureReader2 config I added untrustedData="true". This forces the imageresizer to load the blob content and process it, rather than bypassing the process. Perhaps not the best solution, but it solved the cache-control issue for now.