index.js

const core = require("@actions/core");
const proc = require("child_process");
const fs = require("fs");

function run() {
  try {
    if (!fs.existsSync(`${process.env["HOME"]}/.ssh`)) {
      fs.mkdirSync(`${process.env["HOME"]}/.ssh`, { recursive: true });
    }

    console.log("Building known hosts");

    proc.execSync(
      `ssh-keyscan -p ${core.getInput("ssh_port")} ${core.getInput(
        "domain",
      )} >> ${process.env["HOME"]}/.ssh/known_hosts`,
      {
        stdio: [null, null, null],
        timeout: 20000,
      },
    );

    console.log("Finished building known hosts!");
    console.log("Starting ssh-agent");

    var sshOutput = proc.execFileSync(`ssh-agent`, [
      "-a",
      core.getInput("ssh_auth_sock"),
    ]);

    sshOutput
      .toString()
      .split("\n")
      .forEach((line) => {
        var regexp = /=(.*); /g;
        if (line.includes("SSH_AUTH_SOCK")) {
          const sock = regexp.exec(line)[1];
          core.exportVariable("SSH_AUTH_SOCK", sock);
          console.log(`Agent socket is ${sock}`);
        }

        if (line.includes("SSH_AGENT_PID")) {
          const pid = regexp.exec(line)[1];
          core.exportVariable("SSH_AGENT_PID", pid);
          console.log(`Agent PID is ${pid}`);
        }
      });

    console.log("Exported agent variables");
    console.log("Started ssh-agent!");
    console.log("Adding identity");

    proc.execSync("ssh-add -", {
      stdio: [null, null, null],
      input: core.getInput("private_key").trim() + "\n",
    });

    console.log("Added identity!");
    console.log("ssh-agent is ready to use");
  } catch (error) {
    console.log("Encountered an error:");
    console.log(error.message);
    process.exit(1);
  }
}

run();