Nginx configuration for single page app and nested directories - nginx

Question

I have a directory/files structure such as:
root/
a/
utils.js
b/
assets/
styles.css
app.js
index.html
And I want to configure nginx to serve files from a directory directly if exist and have single page app in directory b (if file in path exists the it wil be served directly, nd if not the fallback will end up at index.htm file.
For example:
myapp.com/a/utils.js will return that file.
myapp.com/b/ or myapp.com/b/foo will display index.html
myapp.com/b/assets/style.css will return directly css file
I tries multiple different configurations and non had worke so far. For exampe the simplest:
server {
listen 80;
root /root;
index index.html;
location / {
try_files $uri $uri/ /index.html =404;
}
}
I also tries something to serve different directories:
server {
listen 80;
root /root;
index index.html;
location /a {
try_files $uri $uri/ =404;
}
location /b {
try_files $uri $uri/ /index.html =404;
}
}
I tried to define different roots as well:
server {
listen 80;
index index.html;
location /a {
root /root/a;
try_files $uri $uri/ =404;
}
location /b {
root /root/b;
try_files $uri $uri/ /index.html =404;
}
}
Nginx seems to ignore existing files and ends up returning 404 page at all times. When I try to access soe existing file directly it gets redirected to / (root) url regardless.

Answer 1

The last parameter of a try_files statement is the default action. There can only be one. Many of your examples have two. See this document for details.
The correct URI for your index.html file is /b/index.html which is what you need to use for the default action of the try_files statement.
This should meet your requirements:
location / {
try_files $uri $uri/ /b/index.html;
}
You do not state what should happen with the URI /a/foo. In the above case, it would also return index.html. If you need it to return a 404 response, you would use:
location / {
try_files $uri $uri/ =404;
}
location /b {
try_files $uri $uri/ /b/index.html;
}
See this document for more.