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mirror of https://github.com/octoleo/restic.git synced 2024-12-28 04:56:04 +00:00

Merge pull request #1281 from prattmic/gcs_perms

gs: allow backend creation without storage.buckets.get
This commit is contained in:
Alexander Neumann 2017-09-26 09:38:33 +02:00
commit 801dbb6d03
3 changed files with 59 additions and 21 deletions

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@ -22,6 +22,11 @@ Important Changes in 0.X.Y
untangle mixed files automatically.
https://github.com/restic/restic/pull/1265
* The Google Cloud Storage backend no longer requires the service account to
have the `storage.buckets.get` permission ("Storage Admin" role) in `restic
init` if the bucket already exists.
https://github.com/restic/restic/pull/1281
Small changes
-------------

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@ -411,16 +411,18 @@ Restic connects to Google Cloud Storage via a `service account`_.
For normal restic operation, the service account must have the
``storage.objects.{create,delete,get,list}`` permissions for the bucket. These
are included in the "Storage Object Admin" role. For ``restic init``, the
service account must also have the ``storage.buckets.get`` and
``storage.buckets.create`` (if the bucket does not exist) permissions. These
are included in the "Storage Admin" role.
are included in the "Storage Object Admin" role.
`Create a service account key`_ and download the JSON credentials file.
``restic init`` can create the repository bucket. Doing so requires the
``storage.buckets.create`` permission ("Storage Admin" role). If the bucket
already exists that permission is unnecessary.
In addition, you need the Google Project ID that you can see in the Google
Cloud Platform console at the "Storage/Settings" menu. Export the path to the
JSON key file and the project ID as follows:
To use the Google Cloud Storage backend, first `create a service account key`_
and download the JSON credentials file.
Second, find the Google Project ID that you can see in the Google Cloud
Platform console at the "Storage/Settings" menu. Export the path to the JSON
key file and the project ID as follows:
.. code-block:: console
@ -436,7 +438,7 @@ bucket `foo` at the root path:
enter password for new backend:
enter password again:
created restic backend bde47d6254 at gs:restic-dev-an:foo2
created restic backend bde47d6254 at gs:foo:/
[...]
The number of concurrent connections to the GCS service can be set with the
@ -444,7 +446,7 @@ The number of concurrent connections to the GCS service can be set with the
established.
.. _service account: https://cloud.google.com/storage/docs/authentication#service_accounts
.. _Create a service account key: https://cloud.google.com/storage/docs/authentication#generating-a-private-key
.. _create a service account key: https://cloud.google.com/storage/docs/authentication#generating-a-private-key
Password prompt on Windows

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@ -99,27 +99,58 @@ func Open(cfg Config) (restic.Backend, error) {
return open(cfg)
}
// Create opens the gs backend at the specified bucket and creates the bucket
// if it does not exist yet.
// Create opens the gs backend at the specified bucket and attempts to creates
// the bucket if it does not exist yet.
//
// In addition to the permissions required by Backend, Create requires these
// permissions:
// * storage.buckets.get
// * storage.buckets.create (if the bucket doesn't exist)
// The service account must have the "storage.buckets.create" permission to
// create a bucket the does not yet exist.
func Create(cfg Config) (restic.Backend, error) {
be, err := open(cfg)
if err != nil {
return nil, errors.Wrap(err, "open")
}
// Create bucket if it doesn't exist.
// Try to determine if the bucket exists. If it does not, try to create it.
//
// A Get call has three typical error cases:
//
// * nil: Bucket exists and we have access to the metadata (returned).
//
// * 403: Bucket exists and we do not have access to the metadata. We
// don't have storage.buckets.get permission to the bucket, but we may
// still be able to access objects in the bucket.
//
// * 404: Bucket doesn't exist.
//
// Determining if the bucket is accessible is best-effort because the
// 403 case is ambiguous.
if _, err := be.service.Buckets.Get(be.bucketName).Do(); err != nil {
bucket := &storage.Bucket{
Name: be.bucketName,
gerr, ok := err.(*googleapi.Error)
if !ok {
// Don't know what to do with this error.
return nil, errors.Wrap(err, "service.Buckets.Get")
}
if _, err := be.service.Buckets.Insert(be.projectID, bucket).Do(); err != nil {
return nil, errors.Wrap(err, "service.Buckets.Insert")
switch gerr.Code {
case 403:
// Bucket exists, but we don't know if it is
// accessible. Optimistically assume it is; if not,
// future Backend calls will fail.
debug.Log("Unable to determine if bucket %s is accessible (err %v). Continuing as if it is.", be.bucketName, err)
case 404:
// Bucket doesn't exist, try to create it.
bucket := &storage.Bucket{
Name: be.bucketName,
}
if _, err := be.service.Buckets.Insert(be.projectID, bucket).Do(); err != nil {
// Always an error, as the bucket definitely
// doesn't exist.
return nil, errors.Wrap(err, "service.Buckets.Insert")
}
default:
// Don't know what to do with this error.
return nil, errors.Wrap(err, "service.Buckets.Get")
}
}