[
https://issues.apache.org/jira/browse/MESOS-6360?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Qian Zhang updated MESOS-6360:
------------------------------
Description:
Currently when user launches a container from a Docker image via universal
containerizer, we always handle the whiteout files in
{{ProvisionerProcess::__provision()}} regardless of which backend is used.
However this is actually not correct, because the way to handle whiteout files
is backend dependent, that means for different backends, we need to handle
whiteout files in different ways, e.g.:
* AUFS backend: It seems the AUFS whiteout ({{.wh.<filename/dirname>}} and
{{.wh..wh..opq}}) is the whiteout standard in Docker (see [this comment |
https://github.com/docker/docker/blob/v1.12.1/pkg/archive/archive.go#L259:L262]
for details), so that means after the Docker image is pulled, its whiteout
files in the store are already in aufs format, then we do not need to do
anything about whiteout file handling because the aufs mount done in
{{AufsBackendProcess::provision()}} will handle it automatically.
* Overlay backend: Overlayfs has its own whiteout files (see [this doc |
https://www.kernel.org/doc/Documentation/filesystems/overlayfs.txt] for
details), so we need to convert the aufs whiteout files to overlayfs whiteout
files before we do the overlay mount in {{OverlayBackendProcess::provision}}
which will automatically handle the overlayfs whiteout files.
* Copy backend: We need to manually handle the aufs whiteout files when we copy
each layer in {{CopyBackendProcess::_provision()}}.
was:
Currently when user launches a container from a Docker image via universal
containerizer, we always handle the whiteout files in
{{ProvisionerProcess::__provision()}} regardless of which backend is used.
However this is actually not correct, because the way to handle whiteout files
is backend dependent, that means for different backends, we need to handle
whiteout files in different ways, e.g.:
* AUFS backend: It seems the AUFS whiteout ({{.wh.<filename/dirname>}} and
{{.wh..wh..opq}}) is the whiteout standard in Docker (see [this comment |
https://github.com/docker/docker/blob/v1.12.1/pkg/archive/archive.go#L259:L262]
for details), so that means after the Docker image is pulled, the whiteout
files in the store in it are already in aufs format, then we do not need to do
anything about whiteout file handling because the aufs mount done in
{{AufsBackendProcess::provision()}} will handle it automatically.
* Overlay backend: Overlayfs has its own whiteout files (see [this doc |
https://www.kernel.org/doc/Documentation/filesystems/overlayfs.txt] for
details), so we need to convert the aufs whiteout files to overlayfs whiteout
files before we do the overlay mount in {{OverlayBackendProcess::provision}}
which will automatically handle the overlayfs whiteout files.
* Copy backend: We need to manually handle the aufs whiteout files when we copy
each layer in {{CopyBackendProcess::_provision()}}.
> The handling of whiteout files in provisioner is not correct
> ------------------------------------------------------------
>
> Key: MESOS-6360
> URL: https://issues.apache.org/jira/browse/MESOS-6360
> Project: Mesos
> Issue Type: Bug
> Reporter: Qian Zhang
> Assignee: Qian Zhang
>
> Currently when user launches a container from a Docker image via universal
> containerizer, we always handle the whiteout files in
> {{ProvisionerProcess::__provision()}} regardless of which backend is used.
> However this is actually not correct, because the way to handle whiteout
> files is backend dependent, that means for different backends, we need to
> handle whiteout files in different ways, e.g.:
> * AUFS backend: It seems the AUFS whiteout ({{.wh.<filename/dirname>}} and
> {{.wh..wh..opq}}) is the whiteout standard in Docker (see [this comment |
> https://github.com/docker/docker/blob/v1.12.1/pkg/archive/archive.go#L259:L262]
> for details), so that means after the Docker image is pulled, its whiteout
> files in the store are already in aufs format, then we do not need to do
> anything about whiteout file handling because the aufs mount done in
> {{AufsBackendProcess::provision()}} will handle it automatically.
> * Overlay backend: Overlayfs has its own whiteout files (see [this doc |
> https://www.kernel.org/doc/Documentation/filesystems/overlayfs.txt] for
> details), so we need to convert the aufs whiteout files to overlayfs whiteout
> files before we do the overlay mount in {{OverlayBackendProcess::provision}}
> which will automatically handle the overlayfs whiteout files.
> * Copy backend: We need to manually handle the aufs whiteout files when we
> copy each layer in {{CopyBackendProcess::_provision()}}.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
