Mini reverse proxy server written in rust

• Static file server.
• HTTPS
• CORS
• The optional configuration file can be written in JSON or TOML.
• minijinja templates with custom functions:
  • read, write and remove files from the filesystem.
  • Send http requests in the template.
  • Execute commands in the template.
  • Reverse proxy.
  • Modify the response headers and status in the template.
  • Parse and format to:
    • JSON
    • TOML
    • FormData
• Safe rust and good code organization.
• No panics after startup (every panic is a bug).
• Extensively tested with hurl.
• Good debugging experience with the server displaying requests in the terminal and error messages in templates for humans.
• Designed following the principles of UNIX philosophy.

cargo install minirps

Alternatively you can use one of the precompiled binaries available with each release (currently generic Linux only).

minirps -h

minirps path/to/static/folder

minirps -a path/to/static/folder

minirps -i "/*.md" path/to/static/folder

minirps -i "/**/*.md" path/to/static/folder

minirps -p 4000 path/to/static/folder

minirps path/to/static/folder -c path/to/cert.pem -k path/to/key.pem

minirps -o path/to/static/folder

The supported formats are JSON and TOML.

minirps -f path/to/config/file

Here it is assumed that there are minijinja templates users.html and edit_user.html

config.toml

templates = "path/to/templates/folder"
assets = "path/to/static/folder"
port = 4000
cert = "path/to/cert.pem"
key = "path/to/key.pem"
cors = []

[[routes]]
method = "GET"
path = "/api/users"
template = "users.html"

[[routes]]
method = "GET"
path = "/api/users/:id"
template = "edit_user.html"

[[routes]]
method = "POST"
path = "/api/users/:id"
template = "edit_user.html"

Alternatively you can use a JSON file

config.json

{
  "templates": "path/to/templates/folder",
  "assets": "path/to/static/folder",
  "port": 4000,
  "cert": "path/to/cert.pem",
  "key": "path/to/key.pem",
  "cors": [],
  "routes": [
    {
      "method": "GET",
      "path": "/api/users",
      "template": "users.html"
    }, {
      "method": "GET",
      "path": "/api/users/:id",
      "template": "edit_user.html"
    }, {
      "method": "POST",
      "path": "/api/users/:id",
      "template": "edit_user.html"
    }
  ]
}

minirps -f examples/demo/config.toml

alternatively

minirps -f examples/demo/config.json

Here it was implemented:

• Command Line: use of the command line through a minijinja custom function.
• Periodic Table: A periodic table web interface was built from a JSON file.
• Star Wars API: Web interface for swapi Star Wars API.
• Note taking app: An example using the file system to save and read data.
• Form Data: Sending and reading examples.
• CORS: A working demo of a CORS request, needs both servers running.

In this example, a static server and some routes are built to test the use of reverse proxy and templates automatically using hurl.

minirps -f examples/tests/config.toml

hurl --test examples/tests/test.hurl

The objective of this project is to deliver an http server in a single self-contained binary.

Where the basics should be obtained without any configuration file:

• static file server.
• HTTPS
• CORS

And where other reverse proxy functionalities are obtained with simple configurations.

Templates have the ability to send requests, read and write files and execute commands.

This way they can interact with resources such as databases without the need for a complete scripting language such as php, python, ruby...

A small, highly extensible server, without having to manage operating system versions, dependencies and packages.

It simply works!

Command line arguments take priority over config file if both are present.

Command line argument paths are relative to the current working directory.

config paths are relative to your own directory.

Currently, any changes to config, the server must be restarted for them to be applied.

Optional integer port number to run the server on, default: 3000

Whether to display hidden files.

In case of confirmation via the command line or config file they will be displayed.

List of files to ignore using glob expressions.

If the -i option is passed on the command line it will be appended to the list.

The routes must be considered in relation to the assets folder and not the working directory.

For a complete reference of glob expressions and possible bugs check this library.

Optional array of strings representing allowed origins for CORS requests.

An empty array allows all origins.

If this variable is not defined,CORS will be disabled.

Optional string with the public key file path for the https server.

Only if the cert and key are available will the server run over https.

Optional string with the private key file path for the https server.

Only if the cert and key are available will the server run over https.

Optional string with the static files folder path.

Optional string with the path to the minijinja templates folder.

Optional string with the path where templates can read, write and remove files. If not passed, these functions will be unavailable to templates.

Optional array of objects that define routes:

• method string: one of the http methods:
  • GET
  • POST
  • DELETE
  • PUT
  • PATCH
  • HEAD
  • OPTIONS
  • TRACE
  • CONNECT
• path string: the path associated with the route, :var is acceptable for setting path variables (ex: /api/user/:id).
• template string: the template path associated with this route within the templates folder.

The method associated with this route. It is useful when the same template is used in many routes.

It is the junction of the path and the route query.

http://localhost:3000/api/users?name=john#me => /api/users?name=john

It is the route as declared in the config file.

/api/user/:id

The associated path passed by the client in the request.

http://localhost:3000/api/users?name=john => /api/users

The associated query string passed by the client in the request.

http://localhost:3000/api/users?name=john => name=john

The associated object of the path params associated with the client request on a given route.

• name string: The name of the parameter as declared in the route.
• value string: The value of the parameter passed in the path.

/api/user/:id => http://localhost:3000/api/user/25 => {"id": "25"}

The associated object of the query params associated with the client request.

• name string: The name of the parameter passed in the query.
• value string: The value of the parameter passed in the query.

http://localhost:3000/api/users?name=john => {"name": "john"}

The associated object of the headers passed by the client in the request.

Note that all header keys are in lowercase.

• name string: The name of the header passed in the request.
• value string: The value of the header passed in the request.

Content-Type: text/plain => {"content-type": "text/plain"}

The body passed by the client in the request.

Variables that, if defined, modify the behavior of the server response.

It only works if they are declared outside the blocks to be returned in the template's global state.

The response body is always the result of the template, and this variable allows you to modify the status code and headers.

• status (integer?): The new response status code, if not passed, will use 200 by default.
• headers ({name: value}?): The headers that should be changed in the response.

An example of a redirect.

{% set modify = {"status": 303, "headers": {"Location": "/new/location"}} %}

Uses a proxy instead of the template result.

• url (string): The proxy URL, is required.
• method (string?): The method used for the proxy request. By default, the method passed in the original request.
• headers ({name: value}?): The headers that should be changed in the proxy request. By default, do not change any header.
• body (binary?): The body of the proxy request. By default, the original body.

A simple proxy that retains the request method, headers, body and path and just directs it to another host.

{% set proxy = {"url": "https://another.host.ip"~url} %}

Executes a command passed in the template.

This function does not raise errors, in case of failure it returns the code 999999, and the error message.

• cmd string: The command to be executed by the system.
• code integer: The response code, in general zero indicates OK, and a number greater than zero the error code.
• stdout binary: The standard output of the executed command.
• stderr binary: The error message returned.

List files in the current directory on UNIX systems.

{% set res = command("ls -l") %}
{% set output = res.stdout | parse("text") %}

Reads the contents of a file, if it does not exist returns None.

This function does not raise errors, any read error will return None.

It will only be available if the config file contains the data property with the folder that contains the files that can be read and modified.

• file string: The path of the file to read.
• data binary?: The contents of the file or None in case of errors.

{% set content = read("some/file.json") | parse("json") %}

This function also works with a directory, which in this case will return an array with information about the files contained in it.

• dir string: If the path passed is a directory.

info

• accessed string: Last access date (%Y-%m-%d %H:%M:%S).
• created string: Creation date (%Y-%m-%d %H:%M:%S).
• modified string: Modification date (%Y-%m-%d %H:%M:%S).
• is_dir bool: True if it is a directory.
• is_file bool: True if it is a file.
• is_symlink bool: True if it is a symbolic link.
• name string: Entry name.
• len u64: Size in bytes.

{% set content = read("some/dir") %}
{% for entry in content %}
  {{entry.name}}
{% endfor %}

Writes to a file. If necessary, create folders for the file. Always overwrites content if it exists.

If an error occur, the error text will be returned, otherwise None. Therefore, it does not raise errors.

It will only be available if the config file contains the data property with the folder that contains the files that can be read and modified.

• file string: The file path.
• data binary: The raw data to be written.
• error string?: Error message or None.

{% set data = "Hello world!" %}
{{write("some/file.txt", data | bytes)}}

Removes a file or directory recursively.

If an error occur, the error text will be returned, otherwise None. Therefore, it does not raise errors.

It will only be available if the config file contains the data property with the folder that contains the files that can be read and modified.

• entry string: The path of the file or directory to be removed.
• error string?: Error message or None.

{{remove("some/dir")}}

{{remove("some/file.txt")}}

Sends a synchronous request to an external resource.

This function does not raise errors, any error in the request will be returned status code 400 with the body containing the error message.

• url string: The URL of the request.
• body binary: The body of the request.
• status integer: The HTTP status code of the response.
• headers {name string: value string}: Response headers.
• body binary: Response body.
• method:
  • get (url) -> {status, headers, body}
  • delete (url) -> {status, headers, body}
  • head (url) -> {status, headers, body}
  • options (url) -> {status, headers, body}
  • post (url, body) -> {status, headers, body}
  • put (url, body) -> {status, headers, body}
  • patch (url, body) -> {status, headers, body}

{% set response = get("https://some/api") %}
{% set data = response.body | parse("json") %}

{% set body = "some data" %}
{% set response = post("https://some/api", body | bytes) %}
{% set message = response.body | parse("text") %}

Prints a message from the template on the terminal.

• message string: The content of the message.

{{ log("hi!") }}

Converts the raw data returned from some function to a template variable using the passed encoding.

This function raises an error if you use an unsupported encoding or if the decoding fails.

Returning the request with status code 500 in case of error.

• data binary: Raw data returned from some function.
• encoding string: The encoding to be used when reading the data. Supported encodings:
  • form: FormData
  • json: JSON
  • toml: TOML
  • text: It just transforms the data into text.
• result: A value supported by the template with associated data.

{% set data = read("some/file.txt") | parse("text") %}

{% set response = get("https://some/api") %}
{% set data = response.body | parse("json") %}

Converts a template variable to a formatted string.

This function raises an error if you use an unsupported encoding or if the encoding fails.

Returning the request with status code 500 in case of error.

• data: Any template variable.
• encoding string: The type of encoding to be adopted when formatting the text. Supported encodings:
  • form: FormData
  • json: JSON
  • toml: TOML
  • debug: Uses rust pretty print formatter.
• text string: The text after encoding.

{% set data = {"name": "John", "age": 30} %}
{% set text = data | format("form") %}
{{text}}

name=John&age=30

Converts text to binary format.

• data string: Any text.
• raw binary: Text converted to binary.

{% set error = write('hello.txt', 'Hello World!' | bytes) %}

{% set response = post('http://myip/some/api', 'Hello World!' | bytes) %}

Currently, only binaries for generic versions of Linux are distributed across releases.

sudo apt install pkg-config libssl-dev musl-tools
rustup update
rustup target add x86_64-unknown-linux-musl
cargo update
cargo build --release --target x86_64-unknown-linux-musl

It's a very simple project. Any contribution, any feedback is greatly appreciated.

If this project was useful to you, consider giving it a star on github, it's a way to increase evidence and attract more contributors.

This work would not be possible if it were not for these related projects:

• minijinja
• axum
• reqwest
• hurl
• serde
• clap
• glob-match

A huge thank you to all the people who contributed to these projects.