Dear friends
I have a logo picture (logo.png) in node red main folder :
~/.node-red/Public
I used a ui_template to show it.
Every thing is OK and it shows in dashboard.
Now the problem is, every timeI reboot, I need to re-authorize to see the picture.
I edit httpStatic from :
/home/pi/.node-red/settings.js
to :
httpStatic: '/home/pi/.node-red/public'
Also add :
public/logo.png
The next time :
/logo.png
And at last :
logo.png
to :
/home/pi/.node-red/node_modules/node-red-dashboard/dist/dashboard.appcache
But none works !
How can I show my picture (logo.png) in my password protected dashboard that don't need re-authorization every time?
You could create an endpoint and serve it (or any file) thru a different URL.
See Here
The logo.png is in my local storage!
Isn't it possible to show it like node-red logo at the left corner with no extra node ?
http://127.0.0.1:1880/red/images/node-red.svg
Yes, but as you have it (node-red / dashboard) secured, its, erm, secured & thus needs security credentials to be accessed! 
Thats why i suggested a workaround - setting up another (unsecured) end point.
You can server the single file if you want (i.e. use a fixed endpoint that only returns the one file)
There may be other solutions but I see no reason for resisting this as a solution?
If you want greater control over things, then perhaps consider ui-builder. you dont get anywhere near the amount of hand holding dashboard gives you - but you can do pretty much anything you want.
?
What does that have to do with accessing an image on your server on a dashboard?
The weather icons are shown IN the dashboard & thus you would need to log in to see them.