I have made several versions of this. My new one is based on heavy-gauge steel hog panels, also known as livestock panels. I had, have some scraps kicking around that needed repurposing. 
The photographs are actually celebrating my moving the tool rack from the “Tool Port” to the adjacent “Car Port”. Since my diminutive Honda CRX is occupying a full-sized parking space, there is plenty of room for the tools which were contributing to the overcrowding in my tool shed.
Last year I repurposed a plastic strip door, but snow blew in and made a hash of it. Since I never walk or drive through that opening, I disabled the strip movement, making it solid so I could put the tools next to it without fear of weather exposure.
The doggie door on the lower right of the opening is because Bosco LOVES running around the building and zooming through that door as part of the chase game he plays with kennel mate Scooter.
