# GitPad

A lightweight git web interface with:

* **editing support** (create, edit, move and remove files)
* **Markdown rendering** (for files named `*.md`)
* a **multi-user mode** with file sharing & collaborative editing

You can install GitPad with:

```
$ cargo install gitpad
```

GitPad needs to be started from inside of a bare Git repository.
For example:

```
$ git init --bare example.git
$ cd example.git/
$ gitpad
Listening on http://127.0.0.1:8000
```

By default GitPad is in single-user mode, serving the branch pointed to by `HEAD`.

**WARNING**: The `lua` feature is enabled by default. Lua sandboxing is still
experimental, so giving users access who you don't trust might lead to a system
compromise.

## Multi-user mode

Multi-user mode requires you to set up a reverse-proxy that authenticates users
and sets the `Username` header. Every user gets their own private Git branch,
named exactly like their username and served under `/~{username}`.  Users can
share files/directories with other users by creating a `.shares.txt` file.

The simplest authentication mechanism is HTTP Basic Auth.  With NGINX a
reverse-proxy could be configured as follows:

```nginx
server {
    listen 80;
    listen [::]:80;

    server_name notes.localhost;
    client_max_body_size 5M;

    location / {
        auth_basic 'Restricted';
        auth_basic_user_file /etc/nginx/gitpad_passwd;
        proxy_set_header Username $remote_user;

        proxy_pass http://localhost:8000;

        # Or if you start GitPad with --socket /srv/sockets/gitpad.sock
        # proxy_pass http://unix:/srv/sockets/gitpad.sock;
    }
}
```

For instructions on how to create the `auth_basic_user_file`,
refer to the [NGINX documentation](https://docs.nginx.com/nginx/admin-guide/security-controls/configuring-http-basic-authentication/).

Once you have set this up start GitPad in multi-user mode by running it with the
`-m` flag.

## Configuring committer identities

In single-user mode GitPad just uses the
committer identity from your git config.

In multi-user mode GitPad defaults to `{username} <{username}@localhost.invalid>`.
Committer identities can be configured by creating a `users.toml` file in the
`gitpad` branch, with sections like the following:

```toml
[johndoe]
name = "John Doe"
email = "john@example.com"
```

## Lua templates

You can define Lua functions in `.lua` files within the `modules/` directory
and then call them within `.md` files using the `{{modulename.functionname}}`
syntax. For example if you create `modules/example.lua` with:

```lua
function greet(args)
    return 'Hello ' .. args[1] .. '!'
end

function sum(args)
    return args.x + args.y
end

return {greet=greet, sum=sum}
```

within Markdown files `{{example.greet|world}}` will become
`Hello world!` and `{{example.sum|x=3|y=5}}` will become 8.

Note that:

* If no module name is given it defaults to `default` so e.g. `{{foo}}`
  will attempt to call the `foo` function defined in `modules/default.lua`.
* In order to pass `|` or `}}` within arguments you need to
  escape them by prefixing a slash e.g. `{{foo| \| \}} }}`.
* Within `<pre>` and `<raw>` tags and HTML comments no special syntax is interpreted.
* Note that none of these constructs can be nested. E.g. `{{foo|{{bar}} }}` or
  `{{foo|<raw>test</raw>}}` will not work as you might expect.

## Lua shebangs

Files can start with a shebang like `#!hello`, which will
interpret the following text with the `view` function returned
by in this case `bin/hello.lua`, e.g.

```lua
function view(text)
    return '<pre>' .. gitpad.html_escape(string.upper(text)) .. '</pre>'
end

return {view=view}
```

## Contributing

Feedback, bug reports and suggestions are welcome!