yaf

yaf - Yet Another (Temporary) Fileshare

yaf is a simple Go program to handle file uploads. If you also want to serve the uploaded files, consider a web server like nginx.

Installation with docker-compose and local build

Clone the directory:

git clone https://github.com/lyx0/yaf.git

Run tests (optional):

go test

Manual Installation

Clone the directory:

git clone https://github.com/lyx0/yaf.git

Build the executable:

go build

Run tests (optional):

go test

If you plan on using a systemd service or another init system, you might want to move the yaf executable to a different directory (e.g. /opt) at this point; you know your setup best.

Configuration

yaf

There are just a few parameters that need to be configured for yaf. Refer to the example.conf file:

Port:       4711
# a comment
LinkPrefix: https://yaf.example.com/
FileDir:    /var/www/yaf/
LinkLength: 5
ScrubExif: true
# Both IDs also refer to the "Orientation" tag, included for illustrative purposes only
ExifAllowedIds: 0x0112 274
ExifAllowedPaths: IFD/Orientation
ExifAbortOnError: true
FileExpiration: false

Make sure the user running yaf has suitable permissions to read, and write to, FileDir. Also note that LinkLength directly relates to the number of files that can be saved. Since yaf only uses alphanumeric characters for file name generation, a maximum of (26 + 26 + 10)^LinkLength names can be generated.

A Note on EXIF Scrubbing

EXIF scrubbing can be enabled via the ScrubExif config key. When enabled, all standard EXIF tags are removed on uploaded JPEG and PNG images per default. It is meant as a last-line "defense mechanism" against leaking PII, such as GPS information on pictures. If possible, you should always prefer disabling capturing potentially sensitive EXIF tags when creating the images!

Obviously, EXIF tags serve a purpose and you may want to keep some of the information, e.g., image orientation. The ExifAllowedIds and ExifAllowedPaths config keys can be used to selectively allow specific tags to survive the scrubbing. The IDs for standard tags can be found in 1. You may specify tag IDs in decimal and hexadecimal notation. (In the latter case, the ID must start with 0x.)

The path specification for ExifAllowedPaths relies on the format implemented in go-exif which is "documented" in machine-readable format in 2. Multiple paths can be specified, separated by a space. The path format is as follows:

1. For tags in the main section: IFD/<GroupName>/<FieldName>. Examples: IFD/Orientation, IFD/Exif/Flash, IFD/GPSInfo/GPSTimeStamp. You will probably want to use both 1 and 2 in combination if you plan to specify allowed tags by path.

2. Tags in the thumbnail section follow the same format but paths start with IFD1/ instead of IFD.

nginx

If you use a reverse-proxy to forward requests to yaf, make sure to correctly forward the original request headers. For nginx, this is achieved via the proxy_pass_request_headers on; option.

If you want to limit access to yaf (e.g. require basic authentication), you will also need to do this via your reverse-proxy.

caddy

I provided a Caddyfile.example for you that should be pretty self explanatory. Copy the contents to your own Caddyfile and be sure to move the contents of the dist folder to your file directory so you can enjoy the really pretty high quality frontend page.

yaf.example.com {
    root * /path/to/filedir/
    file_server

    reverse_proxy /upload localhost:4711
    reverse_proxy /uploadweb localhost:4711
}

Running

Manually

After adjusting the configuration file to your needs, run:

yaf -configFile yaf.conf

Of course, you can also write a init system script to handle this for you.

Running from docker-compose

Copy configuration file and fill it in:

cp example.conf yaf.conf

Configure the docker-compose.yml volume paths:

vim docker-compose.yml

Build the local docker file:

make build

Run the local docker file with docker-compose:

make run

Running from Docker

Building the Docker image and running it locally

docker build -t yaf .
docker run \
    -p 4711:4711 \
    -v /path/to/your/yaf.conf:/app/yaf.conf \
    -v /path/to/local/filedir:/var/www/yaf \
    yaf

Port 4711 is the default port for the server in example.conf, if you've changed this in your config you'll need to change this in the docker run invocations above too.
The above runs forwards the yaf port from 4711 in the container to 4711 on your local system.

Usage

You can use yaf with any application that can send POST requests (e.g. ShareX/ShareNix or just curl). Make sure the file you want to upload is attached as a multipart/form-data field named file. In curl, a request to upload the file /home/alice/foo.txt could look like this:

curl -L -F "file=@/home/alice/foo.txt" yaf.example.com/upload

The response will include a link to the newly uploaded content. Note that you may have to add additional header fields to the request, e.g. if you have basic authentication enabled.

Inspiration

• i by fourtf – a project very similar in scope and size
• filehost by nuuls – a more integrated, fully-fledged solution that offers a web interface and also serves the files