Mini RPS

Mini reverse proxy server written in rust

Features

• very fast single binary with no dependencies
• static file server
• reverse proxy router
• https
• CORS
• consume any API data and create custom responses with minijinja templates
• extensively tested with hurl
• cache rules
• hot reload server in case of file changes
• define once an array of requests based on a variable

Install

cargo install minirps

Usage

Simple static file server

minirps path/to/static/folder

Running on port 4000 instead of 3000

minirps -p 4000 path/to/static/folder

Using https instead of http

minirps -p 4000 path/to/static/folder -c path/to/cert.pem -k path/to/key.pem

Allow CORS from all origins

minirps -a -p 4000 path/to/static/folder -c path/to/cert.pem -k path/to/key.pem

Start the server with a config.toml file

Here the limit of possible configurations passed by command line has been reached.

To create more complex and interesting examples we need a config.toml file

minirps -f path/to/config.toml

Allow CORS for my website

config.toml

assets = "path/to/static/folder"
port = 4000
cert = "path/to/cert.pem"
key = "path/to/key.pem"
cors = [
  "https://www.my-website.com"
]

Allow CORS from my websites of varying origins

config.toml

assets = "path/to/static/folder"
port = 4000
cert = "path/to/cert.pem"
key = "path/to/key.pem"
cors = [
  "http://www.my-website.com",
  "https://www.my-website.com",
  "http://www.my-other-website.com",
  "https://www.my-other-website.com"
]

Allow CORS from all origins

config.toml

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

Add a reverse proxy to an API server running at http://localhost:8000

config.toml

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

# GET https://localhost:4000/api/users => GET http://localhost:8000/users
[[routes]]
method = "GET"
path = "/api/users"

[[routes.requests]]
method = "GET"
url = "http://localhost:8000/users"

# PUT https://localhost:4000/api/users/21 => PUT http://localhost:8000/users/21
[[routes]]
method = "PUT"
path = "/api/users/:id"

[[routes.requests]]
method = "PUT"
url = "http://localhost:8000/users/{{params.id}}"
body = "{{body}}"

Send a plain text response instead of the API response

config.toml

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

# GET https://localhost:4000/api/users => GET http://localhost:8000/users
[[routes]]
method = "GET"
path = "/api/users"

[[routes.requests]]
name = "users"
method = "GET"
url = "http://localhost:8000/users"

[routes.response]
body = """
{% for user in data.users.json %}
  {{user.name}}
{% endfor %}"""
headers = { Content-Type = "text/plain" }

# PUT https://localhost:4000/api/users/21 => PUT http://localhost:8000/users/21
[[routes]]
method = "PUT"
path = "/api/users/:id"

[[routes.requests]]
name = "result"
method = "PUT"
url = "http://localhost:8000/users/{{params.id}}"
body = "{{body}}"

[routes.response]
body = "{% if data.result.status == 200 %}SUCCESS!{% else %}ERROR!{% endif %}"
headers = { Content-Type = "text/plain" }

Send HTML template response instead of API response

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 = []

# GET https://localhost:4000/api/users => GET http://localhost:8000/users
[[routes]]
method = "GET"
path = "/api/users"

[[routes.requests]]
name = "users"
method = "GET"
url = "http://localhost:8000/users"

[routes.response]
body = "{% include 'users.html' %}"
headers = { Content-Type = "text/html" }

# PUT https://localhost:4000/api/users/21 => PUT http://localhost:8000/users/21
[[routes]]
method = "PUT"
path = "/api/users/:id"

[[routes.requests]]
name = "result"
method = "PUT"
url = "http://localhost:8000/users/{{params.id}}"
body = "{{body}}"

[routes.response]
body = "{% include 'edit.html' %}"
headers = { Content-Type = "text/html" }

Examples

static server with cors

In this example, a static server was created and also a CORS request as a showcase.

Static server

minirps assets

CORS server

minirps assets/tests -a -p 4000 -c assets/certs/cert.txt -k assets/certs/key.txt

starwars

In this example minijinja templates were used to consume data from swapi's Star Wars API.

minirps -f examples/starwars.toml

test

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/test.toml

hurl --test examples/test.hurl

Docs

config.toml

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

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

config.toml paths are relative to your own directory.

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

port: integer?

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

cors: [string]?

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.

cert: string?

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.

key: string?

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.

assets: string?

Optional string with the static files folder path.

templates: string?

Optional string with the path to the minijinja templates folder.

routes: [{method: string, path: string, requests: [{...}]?, response: {...}?}]

Optional array of objects that define reverse proxy routes:

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

routes.requests: [{name: string?, method: string, headers: {header: string}?, url: string, body: string?}]?

Requests is an optional array of objects that represent requests that need to be made to generate the response.

• name is an optional string that will be used (if present) to store the response data associated with the request to be made available in minijinja templates.
• method is a required string containing the http method (or a minijinja template) as described in the routes definition.
• headers is an object with the keys been the header to be setted in the request and the values a string containing the value of the header or a minijinja template to generate it.
• headers is an object with the keys being the header to be configured in the request and the values being a string containing the header value or a minijinja template to generate it.
• url is a required minijinja template or a raw string associated with the request.
• body is an optional minijinja template or a raw string associated with the request.

routes.response {status: string?, headers: {header: string}?, body: string?}?

The response starts with the status, headers, and response body of the last request in the requests array, or if not present an empty 200 response, and the properties here are modifiers of the response sent by the reverse proxy to the client.

• status is an optional string or minijinja template that represents an integer to modify the status code of the response.
• headers is an optional object where the keys are the headers to be modified in the response and the values are a string or a minijinja template representing the value associated with the header.
• body is an optional string or minijinja template with the body to be replaced with the original response body.

Available minijinja template variables

path: string

The associated path passed by the client in the request.

Ex.: /api/user/:id => /api/user/25.

query: string?

The associated query string or none passed by the client in the request.

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

headers: {header: string}

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

Note that all header keys are in lowercase.

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

params: {param: string}

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

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

vars: {param: string}

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

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

body: string

The body passed by the client in the request.

json

The body passed by the client in the request converted to json.

If it fails contains the body as a json string.

data: {name: {status: integer, headers: {header: string}, body: string, json}}

The data object is where all the results of the reverse proxy request array are stored. A result is stored only if there is a name associated with it and will be available for the next request or response templates.

• name: Object keys are the name passed in the requests array.
• status: The response status associated with the request.
• headers: The response headers associated with the request (the header name is always lowercase in this object)
• body: The response body as a string associated with the request.
• json: The response body converted to json (or if it fails as json string) associated with the request.

Releases

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

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

Contributing

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

Acknowledgment

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

• minijinja
• axum
• reqwest
• hurl

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