index.js

import * as core from '@actions/core';
import fs from 'fs';
import ini from 'ini';
import https from 'https';
import http from 'http';
import { URL } from 'url';

async function fetchUrl(url, depth = 0) {
    if (depth > 10) {
        throw new Error("Too many redirects: " + url);
    }
    return new Promise((resolve, reject) => {
        const protocol = url.startsWith('https') ? https : http;
        protocol.get(url, (res) => {
            if (res.statusCode >= 300 && res.statusCode < 400 && res.headers.location) {
                let nextUrl = res.headers.location;
                if (!nextUrl.startsWith('http')) {
                    const parsedUrl = new URL(url);
                    nextUrl = new URL(nextUrl, parsedUrl.origin).href;
                }
                fetchUrl(nextUrl, depth + 1).then(resolve).catch(reject);
                return;
            }
            if (res.statusCode !== 200) {
                reject(new Error(`Failed to fetch URL: ${url}, status code: ${res.statusCode}`));
                return;
            }
            let data = '';
            res.on('data', (chunk) => {
                data += chunk;
            });
            res.on('end', () => {
                resolve(data);
            });
        }).on('error', (err) => {
            reject(err);
        });
    });
}


//Support:
// {{VARIABLE}}
async function renderFile(tpl, outfile, datafile) {
    let config = ini.parse(fs.readFileSync(datafile, "utf-8"));
    let content = fs.readFileSync(tpl, "utf-8");
    var matches = [...content.matchAll(/(?<!\$){{\s*(\w+)\s*}}/g)]

    for (let m in matches) {
        console.log(matches[m][0]);
        let match = matches[m][0]
        let name = matches[m][1];
        let value = "";

        if (name in config) {
            value = config[name];
        } else if (name in process.env) {
            value = process.env[name];
        }

        if (value && typeof value === 'string' && value.startsWith("@")) {
            let target = value.substring(1);
            if (target.startsWith("https://")) {
                value = await fetchUrl(target);
            } else {
                value = fs.readFileSync(target, "utf-8");
            }
        }
        if (typeof value === 'string') {
            content = content.replace(new RegExp(match, "g"), value);
        }
    }

    fs.writeFileSync(outfile, content, "utf8");

    console.log("end");




}


async function main() {
    let datafile = core.getInput("datafile");
    if (!datafile) {
        core.debug("No data file is specified.")
    }
    let files = core.getMultilineInput("files").filter(x => x !== "");
    core.debug(files);

    for (let file of files) {
        core.info("Rendering file: " + file);
        let segs = file.split(":");  //template file : output file: [optional datafile]
        let tpl = segs[0].trim();
        let outfile = segs[1].trim();
        let f = datafile;
        if (segs.length > 2) {
            f = segs[2].trim();
        }
        await renderFile(tpl, outfile, f);
    }
}






main().then();