Listing Metrics with Utapi

To make a successful request to Utapi you would need

1. IAM user with a policy giving access to Utapi
2. Sign request with Auth V4

IAM user with a policy giving access to Utapi

Note: The examples here use AWS CLI but any AWS SDK is capable of these actions.

1. Create an IAM user

   aws iam --endpoint-url <endpoint> create-user --user-name utapiuser
   

2. Create access key for the user

   aws iam --endpoint-url <endpoint> create-access-key --user-name utapiuser
   

3. Create a managed IAM policy

   aws iam --endpoint-url <endpoint> create-policy --policy-name utapipolicy \
    --policy-document file://utapipolicy.json
   

   sample utapi policy

   {
   	"Version": "2012-10-17",
   	"Statement": [
   		{
   			"Sid": "utapiMetrics",
   			"Action": [ "utapi:ListMetrics" ],
   			"Effect": "Allow",
   			"Resource": "arn:scality:utapi:::buckets/*"
   		}
   	]
   }

   The user can also be restricted to only some buckets (foo bucket for example) by changing the Resource property to "Resource": "arn:scality:utapi:::buckets/foo"

4. Attach user to the managed policy

   aws --endpoint-url <endpoint> iam  attach-user-policy --user-name utapiuser --policy-arn <policy arn>
   

Now the user utapiuser has access to ListMetrics request in Utapi on all buckets.

Signing request with Auth V4

There are two options here.

You can generate V4 signature using AWS SDKs. See the following urls for reference.

http://docs.aws.amazon.com/general/latest/gr/sigv4_signing.html http://docs.aws.amazon.com/general/latest/gr/sigv4-signed-request-examples.html

or

You can use a nifty command line tool available in Scality's S3. You can git clone S3 repo or docker exec into the S3 container and type.

node bin/list_bucket_metrics

It will generate the following output listing available options.

Usage: list_bucket_metrics [options]

  Options:

    -h, --help                    output usage information
    -V, --version                 output the version number
    -a, --access-key <accessKey>  Access key id
    -k, --secret-key <secretKey>  Secret access key
    -b, --buckets <buckets>       Name of bucket(s)with a comma separator if more than one
    -s, --start <start>           Start of time range
    -e --end <end>                End of time range
    -h, --host <host>             Host of the server
    -p, --port <port>             Port of the server
    --ssl                         Enable ssl
    -v, --verbose

A typical call to list metrics for a bucket demo to Utapi in a https enabled deployment would be

node bin/list_bucket_metrics -a myAccessKey -k mySecretKey -b demo -s 1476231300000 -h 127.0.0.1 -p 8100 -ssl

Both start and end times are time expressed as UNIX epoch timestamps.

Keep in mind, since Utapi metrics are normalized to the nearest 15 min. interval, so start time and end time need to be in specific format as follows.

Start time

Start time needs to be normalized to the nearest 15 minute interval with seconds and milliseconds set to 0. So valid start timestamps would look something like 09:00:00:000, 09:15:00:000, 09:30:00:000 and 09:45:00:000.

For example Date: Tue Oct 11 2016 17:35:25 GMT-0700 (PDT) Unix timestamp: 1476232525320

Here's a typical JS method to get start timestamp

getStartTimestamp(t) {
    const time = new Date(t);
    const minutes = time.getMinutes();
    const timestamp = time.setMinutes((minutes - minutes % 15), 0, 0);
    return timestamp;
},

This would format the start time timestamp to 1476231300000

End time

End time needs to be normalized to the nearest 15 minute end interval with seconds and milliseconds set to 59 and 999 respectively. So valid start timestamps would look something like 09:14:59:999, 09:29:59:999, 09:44:59:999 and 09:59:59:999.

Here's a typical JS method to get end timestamp

getEndTimestamp(t) {
    const time = new Date(t);
    const minutes = time.getMinutes();
    const timestamp = time.setMinutes((minutes - minutes % 15) + 15, 0, -1);
    return timestamp;
}

This would format the end time timestamp to 1476233099999