I have found one way recently: Do you have Stash available? (If not - this may still work, you’ll have to try it. html iframes might work if you don’t have Stash but can make a publicly available website).
First of all, create a HTML report of your model and push it to stash in a repository. You need to make this repository viewable to everyone whom you want to view your model. (You may need to create a customised index.html file and place it at the root if it isn’t there already. Ultimately you just need to edit the paths that it specifies to point to the same files from the new directory location.)
Next you need to go into the repository settings and enable web pages and javascript support. This should allow confluence to preview the repository as a website by clicking on the new globe button in the bottom left.
Now browse through the created website. If you have a diagram in mind that you want to present, then look for a hyperlink to it in this website. When you find such a link, right click and copy the URL. For example, one that goes to a diagram of interest for me is:
https://MY COMPANY HOST/pages/STASH AREA/REPO NAME/BRANCH NAME/browse/MODEL NAME/output/MODEL NAME/6953701f0ce64a93a59fa74b2b900403.html#_TEbKkBy5Ee-0LL77zzh20g
Take note of the last two parts of the hyperlink:
6953701f0ce64a93a59fa74b2b900403
and
_TEbKkBy5Ee-0LL77zzh20g
Now return to your stash repo (not the website view) and drill down into this folder:
output/MODEL NAME/
(there may be too many files for stash to show here, so you might have to do this locally).
Once you get here, follow the path using the two end parts to the hyperlink. So I had to go to:
output/MODEL NAME/6953701f0ce64a93a59fa74b2b900403/_TEbKkBy5Ee-0LL77zzh20g.jpg
This .jpg image will be of the diagram which the hyperlink took you too.
Enter this hyperlink in stash to make sure it takes you to the .jpg of your image (you will have to manually paste it in in bits if you had to use the file explorer).
Finally, copy and paste this hyperlink into Confluence. What should happen is that Confluence recognises this as a Stash object, and attempts to show the contents of the file as a Stash widget. Since it’s a .jpg, it will show an image of your diagram!
From my limited experience, regenerating the HTML report will result in the same links provided that you don’t erase the previous HTML report before generating a new one. If you don’t then existing links will remain as they are but the diagram content will be updated. But please let me know if this is not the case!
I recommend making a library of hyperlinks that match diagrams of interest that you want to show. Once you know these, you can easily paste these all over Confluence. Any time you update the HTML report and push to Stash, these diagrams will all update!