kijin-seija / nginx-conf

NodeJS module for interacting programmatically with an nginx configuration file

nginx-conf

nginx-conf is a node module for making changes to an nginx configuration file programmatically.

Installation

npm install nginx-conf

This library has no dependencies.

Breaking Changes

Version 2.0.0 changed the way that single directives are accessed. In short, everything is now array-indexed.

// Pre 2.0.0:
conf.nginx.foo.bar._value;

// 2.0.0+
conf.nginx.foo[0].bar[0]._value;

Usage

Pretend you have an nginx config file like this one.

Note that all public methods are prefixed with _ so that they (hopefully) don't clash with nginx's directives.

Note: *_content_by_lua_block directives are supported in >=v1.3.0.

// vanilla JS: const NginxConfFile = require('nginx-conf').NginxConfFile;
import {NginxConfFile} from '../../';

const filename = `${__dirname}/../files/readme.conf`;

NginxConfFile.create(filename, function (err, conf) {
    if (err || !conf) {
        console.log(err);
        return;
    }

    // reading values
    console.log('user: ' + conf.nginx.user?.[0]._value);
    console.log('http.server.listen: ' + conf.nginx.http?.[0].server?.[0].listen?.[0]._value);
    console.log('http.server.location.root:' + conf.nginx.http?.[0].server?.[0].location?.[3].root?.[0]._value);

    //writing values
    //NginxConfFile.create() automatically sets up a sync, so that whenever
    //a value is changed, or a node is removed/added, the file gets updated
    //immediately

    const onFlushed = () => {
        console.log('finished writing to disk');
    };

    conf.on('flushed', onFlushed);

    //listen to the flushed event to determine when the new file has been flushed to disk
    if (conf.nginx.events?.[0].connections) {
        conf.nginx.events[0].connections[0]._value = 1000;

        //don't write to disk when something changes
        conf.die(filename);
        conf.nginx.events[0].connections[0]._value = 2000; //change remains local, not in /etc/nginx.conf
    }

    //write to a different file
    conf.live(`${filename}.bak`);

    //force the synchronization
    conf.flush();

    //adding and removing directives
    if (conf.nginx.http) {
        conf.nginx.http[0]._add('add_header', 'Cache-Control max-age=315360000, public');
        console.log(conf.nginx.http[0].add_header?.[0]._value); //Cache-Control max-age=315360000, public

        conf.nginx.http[0]._add('add_header', 'X-Load-Balancer lb-01');
        conf.nginx.http[0]._add('add_header', 'X-Secure true');

        console.log(conf.nginx.http[0].add_header?.[0]._value); //Cache-Control max-age=315360000, public
        console.log(conf.nginx.http[0].add_header?.[1]._value); //X-Load-Balancer lb-01
        console.log(conf.nginx.http[0].add_header?.[2]._value); //X-Secure true

        conf.nginx.http[0]._remove('add_header'); //removes add_header[0]
        conf.nginx.http[0]._remove('add_header', 1); //removes add_header[1]
    }

    //adding a new block
    conf.nginx.http?.[0]._add('server');
    conf.nginx.http?.[0].server?.[0]._add('listen', '80');

    //that'll create something like this:
    /*
      server {
        listen 80;
      }
    */

    //multiple blocks
    conf.nginx.http?.[0]._add('server');
    conf.nginx.http?.[0].server?.[1]._add('listen', '443');

    /*
      server {
        listen 80;
      }
      server {
        listen 443;
      }
    */

    // blocks with values:
    conf.nginx.http?.[0].server?.[1]._add('location', '/');
    conf.nginx.http?.[0].server?.[1].location?.[0]._add('root', '/var/www/example.com');

    /*
      server {
        location / {
          root /var/www/example.com;
        }
      }
    */

    // you can also create empty blocks
    conf.nginx.http?.[0]._add('events', '', []); // events { }

    // lua blocks also work, but you can't put a mismatched "{" or "}" in a comment!
    conf.nginx.http?.[0].server?.[0].location?.[0]._addVerbatimBlock('rewrite_by_lua_block', '\n\
        ngx.say("this is a lua block!")\n\
        res = ngx.location.capture("/memc",\n\
          { args = { cmd = "incr", key = ngx.var.uri } }\n\
        )'
    );

    // remove old listener
    conf.off('flushed', onFlushed);

    // kill process when done writing to disk
    conf.on('flushed', () => {
        console.log('finished writing to disk, exiting');
        process.exit();
    });

    conf.flush();
});

Comments

Support for comments is supported-ish. Comments are attached to directives, and will always be rendered above the directive when using toString() (or _getString()).

Comments can be added, removed and updated via the _comments array on a node.

console.log(conf.nginx.events[0].use[0]._comments.length); // 1
console.log(conf.nginx.events[0].use[0]._comments[0]); // use [ kqueue | rtsig | epoll | /dev/poll | select | poll ];

//remove the comment
conf.nginx.events[0].use[0]._comments.splice(0, 1);

//add a new one
conf.nginx.events[0].use[0]._comments.push('my new comment');
console.log(conf.nginx.events[0].use[0]._comments.length); // 1
console.log(conf.nginx.events[0].use[0]._comments[0]); //my new comment

//update a comment's text
conf.nginx.events[0].use[0]._comments[0] = 'updated';
console.log(conf.nginx.events[0].use[0]._comments[0]); //updated

If the comment is in a weird place (like in the middle of a directive), it'll still be attached to the node. If it's after the directive (after the semicolon or closing brace), it will be attached to the next node, or ignored if it's at the end of the file.

Assuming this nginx configuration:

foo #comment
bar;

You will have this object structure:

console.log(conf.nginx.foo[0]._value); //bar
console.log(conf.nginx.foo[0]._comments[0]); //comment

But if the comment comes after:

foo bar;
#comment

console.log(conf.nginx.foo[0]._value); //bar
console.log(conf.nginx.foo[0]._comments.length); //0

Parser options

Support for go template syntax is provided via NginxParserOptions. By default, templating syntax is not supported.

To enable templating syntax, pass the following NginxParserOptions to the parser.parse or parser.parseFile function(s):

{
  templateSyntax: true
}

Development

git clone [email protected]:tmont/nginx-conf.git
cd nginx-conf
npm install
npm test

If you're making changes, you should run npm run watch in a separate terminal. tsc will output the JavaScript in the dist/ directory. The tests reference the JavaScript files in dist/, not the TypeScript files elsewhere.

Only the stuff in dist/ is included in the NPM package.