Node Amazon S3 Client.
- Not outdated :), developed for node 0.2.x
- RESTful api (
client.get(),client.put(), etc) - Uses node's crypto library (fast!, the others used native js)
- Very node-like low-level request api via
http.Client - Highly documented
- Multipart upload
- TJ Holowaychuk (visionmedia)
The following examples demonstrate some capabilities of knox and the s3 REST API. First things first, create an s3 client:
var client = knox.createClient({
key: '<api-key-here>'
, secret: '<secret-here>'
, bucket: 'learnboost'
});
By default knox will send all requests to the global endpoint (bucket.s3.amazonaws.com).
This works regardless of the region where the bucket is. But if you want to manually set
the endpoint (for performance reasons) you can do it with the endpoint option.
Below we do several things, first we read Readme.md into memory,
and initialize a client request via client.put(), passing the destination
filename as the first parameter (/test/Readme.md), and some headers. Then
we listen for the response event, just as we would for any http.Client request, if we have a 200 response, great! output the destination url to stdout.
fs.readFile('Readme.md', function(err, buf){
var req = client.put('/test/Readme.md', {
'Content-Length': buf.length
, 'Content-Type': 'text/plain'
});
req.on('response', function(res){
if (200 == res.statusCode) {
console.log('saved to %s', req.url);
}
});
req.end(buf);
});
By default the x-amz-acl header is public-read, meaning anyone can GET the file. To alter this simply pass this header to the client request method. Note that the field name MUST be lowercase, do not use 'X-Amz-Acl' etc, as this will currently result in duplicate headers (although different case).
client.put('/test/Readme.md', { 'x-amz-acl': 'private' });
Each HTTP verb has an alternate method with the "File" suffix, for example put() also has a higher level method named putFile(), accepting a src filename and performs the dirty work shown above for you. Here is an example usage:
client.putFile('my.json', '/user.json', function(err, res){
// Logic
});
Another alternative is to stream via Client#putStream(), for example:
var stream = fs.createReadStream('data.json');
client.putStream(stream, '/some-data.json', function(err, res){
// Logic
});
An example of moving a file:
client.put('0/0/0.png', {
'Content-Type': 'image/jpg',
'Content-Length': '0',
'x-amz-copy-source': '/test-tiles/0/0/0.png',
'x-amz-metadata-directive': 'REPLACE'
}).on('response', function(res) {
// Logic
}).end();
Below is an example GET request on the file we just shoved at s3, and simply outputs the response status code, headers, and body.
client.get('/test/Readme.md').on('response', function(res){
console.log(res.statusCode);
console.log(res.headers);
res.setEncoding('utf8');
res.on('data', function(chunk){
console.log(chunk);
});
}).end();
Delete our file:
client.del('/test/Readme.md').on('response', function(res){
console.log(res.statusCode);
console.log(res.headers);
}).end();
Likewise we also have client.deleteFile() as a more concise (yet less flexible) solution:
client.deleteFile('/test/Readme.md', function(err, res){
// Logic
});
The Multipart upload API enables you to upload large objects in parts transactionally. For more info, see here.
Initiate multipart upload:
client.beginUpload('/test/blob.bin', function(e, upinfo){ });
The first argument of the callback contains an error info. If it is null then multipart upload is initiated successfully. The second argument contains information about multipart upload transaction:
upinfo.bucket- name of the bucket to which the multipart upload was initiated;upinfo.key- object key for which the multipart upload was initiated;upinfo.uploadId- ID for the initiated multipart upload.
uploadId is an important field which is used by other multipart upload operations.
Uploading part using response stream:
client.beginUpload('/test/blob.bin', function(e, upinfo){
//Upload the first part
var req = client.putPart('/test/blob.bin', 1, upinfo.uploadId);
var part = new Buffer('Hello, world!\n', 'utf8'); //file part as Buffer
req.end(part); //send buffer
//Upload the second part
req = client.putPart('/test/blob.bin', 2, upinfo.uploadId);
req.end('Ciao, mondo!', 'utf8'); //Italian
});
Uploading part using callback:
client.beginUpload('/test/blob.bin', function(e, upinfo){
var part = new Buffer('Hello, world!', 'utf8');
client.putPart('/test/blob.bin', 1, upinfo.uploadId, part, function(e, pinfo){
console.log('ETag = ' + pinfo.etag);
});
});
This operation completes a multipart upload by assembling previously uploaded parts. You should
specify an array of parts to be commited and upload ID(obtained from beginUpload function).
client.beginUpload('/test/blob.bin', function(e, upinfo){
var part = new Buffer('Hello, world!', 'utf8');
//Upload part of the object
client.putPart('/test/blob.bin', 1, upinfo.uploadId, part, function(e, pinfo){
//complete multipart upload and create a new object on Amazon S3
client.completeUpload('/test/blob.bin', upinfo.uploadId, [pinfo], function(e, cinfo){
console.log('Success: ' + e !== null);
});
});
});
This operations aborts multipart upload and removes all uploaded parts. Upload ID associated with the multipart upload will be invalidated.
client.beginUpload('/test/blob.bin', function(e, upinfo){
var part = new Buffer('Hello, world!', 'utf8');
//Upload part of the object
client.putPart('/test/blob.bin', 1, upinfo.uploadId, part, function(e, pinfo){
//Abort upload
client.abortUpload('/test/blob.bin', upinfo.uploadId, function(success){
console.log('Abort:' + success);
});
});
});
Obtains status of the multipart upload.
client.getParts('/test/blob.bin', '<Upload-Id>', function(err, info){
//Print uploaded parts
for(var p in info.parts) {
console.log('Part #' + info.parts[p].partNumber);
console.log('ETag: ' + info.parts[p].etag);
console.log('Size, in bytes: ' + info.parts[p].size);
}
});
The second parameter of the getParts function can accept object with the following predefined named values:
uploadId- upload ID;max-parts- the maximum number of parts to return in the response body;part-number-marker- the part number after which listing should begin.
For example:
client.getParts('/test/blob.bin', {'uploadId': '<Upload-Id>', 'max-parts': 3}, function(err, info) { });
These paramaters are described here.
If you have partially uploaded file then it is not good solution to use getParts function to calculate remainded size and
resume uploading. Use getUploadInfo function for this purpose:
client.getUploadInfo('/test/blob.bin', '<Upload-id>', function(err, summary){
console.log(summary.totalSize); //total number of already uploaded bytes, this field can be used to compute offset in the blob
console.log(summary.count); //count of already uploaded parts
console.log(summary.lastPart); //the number of the last uploaded part.
});
To run the test suite you must first have an S3 account, and create a file named ./auth, which contains your credentials as json, for example:
{"key":"<api-key-here>",
"secret":"<secret-here>",
"bucket":"<your-bucket-name>"}
Then simply execute:
$ make test
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