I think the only way you could do this is by putting a reverse proxy such as nginx or apache httpd in front of discourse, then passing everything at /blog to another application, and everything else to Discourse.
I would not recommend it if you can avoid it. You can already use a discourse category as a blog, restricting who can post and who can add comments.
so what you are suggest me to do?
But I read that bad for SEO( two seperate sites for google…)
I don’t believe in SEO.
Lol but google believe…
Are you sure?
Yep… this article very deprecated… things changed little bit:
Remember that Google considers sub domains separate from their parent domains: sub.yoursite.com is considered a different site altogether compared to yoursite.com when it comes to search engine authority.
Here is a response from Matt Cutts in email to me:
pretty much everyone who has strong opinions on subdomains vs. subfolders doesn’t know what they’re talking about. They sure do have strong opinions anyway though!
Sorry, I believe Matt Cutts of Google over your random link
OK, here’s a newer (2012) video:
Nothing has changed.
If you insist on doing this, I recommend you deploy Discourse to a subfolder first (www.example.com/forum), and then you can deploy other apps (like your blog) to other subfolders.
Thanks guys, I’ll just put the blog on subdomain.