project.ts

import { webapp_client } from "@cocalc/frontend/webapp-client";
// Write a (relatively SMALL) text file to the file system
// on a compute server, using the file system exec api call.
// This writes to a tmp file, then moves it, so that the
// write is atomic, e.g., because an application of this is
// to our proxy, which watches for file changes and reads the
// file, and reading a file while it is being written can
// be corrupt.

export async function writeTextFileToComputeServer({
  value,
  project_id,
  compute_server_id,
  path, // won't work if path has double quotes in it!
  sudo,
}: {
  value: string;
  project_id: string;
  compute_server_id: number;
  path: string;
  sudo?: boolean;
}) {
  // Base64 encode the value.
  const base64value = Buffer.from(value).toString("base64");
  const random = `.tmp${Math.random()}`;
  if (sudo) {
    // Decode the base64 string before echoing it.
    const args = [
      "sh",
      "-c",
      `echo "${base64value}" | base64 --decode > "${path}${random}" && mv "${path}${random}" "${path}"`,
    ];

    await webapp_client.exec({
      filesystem: true,
      compute_server_id,
      project_id,
      command: "sudo",
      args,
    });
  } else {
    await webapp_client.exec({
      filesystem: true,
      compute_server_id,
      project_id,
      command: `echo "${base64value}" | base64 --decode > "${path}${random}" && mv "${path}${random}" "${path}"`,
    });
  }
}