rsyncwrapper

rsyncwrapper

An async wrapper to the rsync command line utility for Node.js. Also available as the Grunt task grunt-rsync.

Release notes

• 0.2.0 Now launching the rsync command in a shell like child_process.exec does in Node Core. This enables us to use spawn, and avoid exec maxBuffer, while retaining full shell wildcard expansion.
• 0.1.0 Now using child_process.exec as opposed to child_process.spawn to enable proper shell wildcard expansions in the options.src value. SSH option handling has been improved.
• 0.0.1 Initial release.

Prerequisites

A reasonably modern version of rsync (>=2.6.9) in your PATH.

Installation

$ npm install rsyncwrapper

Usage

var rsync = require("rsyncwrapper").rsync;
rsync(options,[callback]);

The callback function gets four arguments (error,stdout,stderr,cmd).

error: An Error object if rsync failed, otherwise null.

stdout: stdout from rsync.

stderr: stderr from rsync.

cmd: The command string that was used to invoke rsync for debugging purposes.

The options argument is an object literal. See below for possible fields.

Options

src [String|Array<String>] *required

Path to src. Can be a single filename, or an array of filenames. Shell wildcard expansion is supported. Examples:

src: "./dist/"
src: ["./dir-a/file1","./dir-b/file2"]
src: "./*.foo"
src: "foo{1,2,3}.txt"
etc.

dest [String] *required

Path to destination. Example, "/var/www/mysite.tld".

ssh [Bool] default: false

Run rsync over ssh. This is false by default. To use this you need to have public/private key passwordless ssh access setup and working between your workstation and your host. If set to true, you should specify ssh host data as part of your src or dest values, e.g. user@1.2.3.4:/var/www/site.

Another good approach is to define a host alias in your ssh config and just reference that alias in your rsync options.

port [String]

If your ssh host uses a non standard SSH port then set it here. Example, "1234".

privateKey [String]

To specify an SSH private key other than the default for this host. Example, "~/.ssh/aws.pem"

recursive [Boolean] default: false

Recurse into directories. This is false by default which means only files in the src root are copied. Equivalent to the --recursive rsync command line flag.

syncDest [Boolean] default: false

Delete objects in dest that aren't present in src. Also deletes files that have been specifically excluded from transfer in dest. Take care with this option, since misconfiguration could cause data loss. Equivalent to setting both the --delete and --delete-excluded rsync command line flags.

syncDestIgnoreExcl [Boolean] default: false

The same as syncDest, but without the --delete-excluded behaviour. One use case for using this option could be while syncing a Node app to a server: you want to exclude transferring the local node_modules folder while retaining the remote node_modules folder.

compareMode [String] enum: "checksum"|"sizeOnly"

By default files will be compared by modified date and file size. Set this value to checksum to compare by a 128bit checksum, or sizeOnly to compare only by file size.

exclude [Array<String>]

Optional array of rsync patterns to exclude from transfer.

include [Array<String>]

Optional array of rsync patterns to include in the transfer, if previously excluded. Exclude patterns are defined before include patterns when building the rsync command.

dryRun [Boolean] default: false

Buffer verbose information to stdout about the actions rsyncwrapper would take without modifying the filesystem. Equivalent to setting both the --dry-run and --verbose rsync command line flags.

onStdout [Function]

Optional callback function. Called every time rsync outputs to stdout. Use this to print rsync output as it happens, rather than all at the end. Example: function (data) { console.log(data) }.

onStderr [Function]

Optional callback function. Called every time rsync outputs to stderr. Use this to print rsync error output as it happens, rather than all at the end. Example: function (data) { console.log(data) }.

args [Array<String>]

Array of additional arbitrary rsync command line options and flags.

The above options are provided for convenience and are designed to cover the most common use cases for rsync, they don't necessarily map directly to single rsync arguments with the same names. If you'd like to handcraft your rsync command then just use the src, dest and args options.

For extra information and subtlety relating to rsync options please consult the rsync manpages.

Tests

Basic tests are run on Vows Async BDD via this package's Gruntfile. To test rsyncwrapper clone the repo and ensure that the devDependancies are present. Additionally ensure that Grunt and Vows are installed globally, and then invoke:

$ npm test

Examples

Copy a single file to another location. If the dest folder doesn't exist rsync will do a mkdir and create it. However it will only mkdir one missing directory deep (i.e. not the equivalent of mkdir -p).

rsync({
    src: "./file.txt",
    dest: "./tmp/file.txt"
},function (error,stdout,stderr,cmd) {
    if ( error ) {
        // failed
        console.log(error.message);
    } else {
        // success
    }
});

Copy the contents of a directory to another folder, while excluding txt files. Note the trailing / on the src folder and the absence of a trailing / on the dest folder - this is the required format when copy the contents of a folder. Again rsync will only mkdir one level deep:

rsync({
    src: "./src-folder/",
    dest: "./dest-folder",
    recursive: true,
    exclude: ["*.txt"]
},function (error,stdout,stderr,cmd) {
    if ( error ) {
        // failed
        console.log(error.message);
    } else {
        // success
    }
});

Syncronise the contents of a directory on a remote host with the contents of a local directory using the checksum algorithm to determine if a file needs copying:

rsync({
    src: "./local-src/",
    dest: "user@1.2.3.4:/var/www/remote-dest",
    ssh: true,
    recursive: true,
    syncDest: true,
    compareMode: "checksum"
},function (error,stdout,stderr,cmd) {
    if ( error ) {
        // failed
        console.log(error.message);
    } else {
        // success
    }
});

TODO

• Add tests to cover usage of more options.