`Mounts` allows users to specify in a much safer way the volumes they
want to use in the container.
This replaces `Binds` and `Volumes`, which both still exist, but
`Mounts` and `Binds`/`Volumes` are exclussive.
The CLI will continue to use `Binds` and `Volumes` due to concerns with
parsing the volume specs on the client side and cross-platform support
(for now).
The new API follows exactly the services mount API.
Example usage of `Mounts`:
```
$ curl -XPOST localhost:2375/containers/create -d '{
"Image": "alpine:latest",
"HostConfig": {
"Mounts": [{
"Type": "Volume",
"Target": "/foo"
},{
"Type": "bind",
"Source": "/var/run/docker.sock",
"Target": "/var/run/docker.sock",
},{
"Type": "volume",
"Name": "important_data",
"Target": "/var/data",
"ReadOnly": true,
"VolumeOptions": {
"DriverConfig": {
Name: "awesomeStorage",
Options: {"size": "10m"},
Labels: {"some":"label"}
}
}]
}
}'
```
There are currently 2 types of mounts:
- **bind**: Paths on the host that get mounted into the
container. Paths must exist prior to creating the container.
- **volume**: Volumes that persist after the
container is removed.
Not all fields are available in each type, and validation is done to
ensure these fields aren't mixed up between types.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
This is similar to network scopes where a volume can either be `local`
or `global`. A `global` volume is one that exists across the entire
cluster where as a `local` volume exists on a single engine.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
In order to be consistent on creation of volumes for bind mounts
we need to create the source directory if it does not exist and the
user specified he wants it relabeled.
Can not do this lower down the stack, since we are not passing in the
mode fields.
Signed-off-by: Dan Walsh <dwalsh@redhat.com>
Implements a `CachedPath` function on the volume plugin adapter that we
call from the volume list function instead of `Path.
If a driver does not implement `CachedPath` it will just call `Path`.
Also makes sure we store the path on Mount and remove the path on
Unmount.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
This allows a user to specify explicitly to enable
automatic copying of data from the container path to the volume path.
This does not change the default behavior of automatically copying, but
does allow a user to disable it at runtime.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Moving all strings to the errors package wasn't a good idea after all.
Our custom implementation of Go errors predates everything that's nice
and good about working with errors in Go. Take as an example what we
have to do to get an error message:
```go
func GetErrorMessage(err error) string {
switch err.(type) {
case errcode.Error:
e, _ := err.(errcode.Error)
return e.Message
case errcode.ErrorCode:
ec, _ := err.(errcode.ErrorCode)
return ec.Message()
default:
return err.Error()
}
}
```
This goes against every good practice for Go development. The language already provides a simple, intuitive and standard way to get error messages, that is calling the `Error()` method from an error. Reinventing the error interface is a mistake.
Our custom implementation also makes very hard to reason about errors, another nice thing about Go. I found several (>10) error declarations that we don't use anywhere. This is a clear sign about how little we know about the errors we return. I also found several error usages where the number of arguments was different than the parameters declared in the error, another clear example of how difficult is to reason about errors.
Moreover, our custom implementation didn't really make easier for people to return custom HTTP status code depending on the errors. Again, it's hard to reason about when to set custom codes and how. Take an example what we have to do to extract the message and status code from an error before returning a response from the API:
```go
switch err.(type) {
case errcode.ErrorCode:
daError, _ := err.(errcode.ErrorCode)
statusCode = daError.Descriptor().HTTPStatusCode
errMsg = daError.Message()
case errcode.Error:
// For reference, if you're looking for a particular error
// then you can do something like :
// import ( derr "github.com/docker/docker/errors" )
// if daError.ErrorCode() == derr.ErrorCodeNoSuchContainer { ... }
daError, _ := err.(errcode.Error)
statusCode = daError.ErrorCode().Descriptor().HTTPStatusCode
errMsg = daError.Message
default:
// This part of will be removed once we've
// converted everything over to use the errcode package
// FIXME: this is brittle and should not be necessary.
// If we need to differentiate between different possible error types,
// we should create appropriate error types with clearly defined meaning
errStr := strings.ToLower(err.Error())
for keyword, status := range map[string]int{
"not found": http.StatusNotFound,
"no such": http.StatusNotFound,
"bad parameter": http.StatusBadRequest,
"conflict": http.StatusConflict,
"impossible": http.StatusNotAcceptable,
"wrong login/password": http.StatusUnauthorized,
"hasn't been activated": http.StatusForbidden,
} {
if strings.Contains(errStr, keyword) {
statusCode = status
break
}
}
}
```
You can notice two things in that code:
1. We have to explain how errors work, because our implementation goes against how easy to use Go errors are.
2. At no moment we arrived to remove that `switch` statement that was the original reason to use our custom implementation.
This change removes all our status errors from the errors package and puts them back in their specific contexts.
IT puts the messages back with their contexts. That way, we know right away when errors used and how to generate their messages.
It uses custom interfaces to reason about errors. Errors that need to response with a custom status code MUST implementent this simple interface:
```go
type errorWithStatus interface {
HTTPErrorStatusCode() int
}
```
This interface is very straightforward to implement. It also preserves Go errors real behavior, getting the message is as simple as using the `Error()` method.
I included helper functions to generate errors that use custom status code in `errors/errors.go`.
By doing this, we remove the hard dependency we have eeverywhere to our custom errors package. Yes, you can use it as a helper to generate error, but it's still very easy to generate errors without it.
Please, read this fantastic blog post about errors in Go: http://dave.cheney.net/2014/12/24/inspecting-errors
Signed-off-by: David Calavera <david.calavera@gmail.com>
This fixes an issue where `docker run -v foo:/bar --volume-driver
<remote driver>` -> daemon restart -> `docker run -v foo:/bar` would
make a `local` volume after the restart instead of using the existing
volume from the remote driver.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
This makes it so when calling `docker run --rm`, or `docker rm -v`, only
volumes specified without a name, e.g. `docker run -v /foo` instead of
`docker run -v awesome:/foo` are removed.
Note that all volumes are named, some are named by the user, some get a
generated name. This is specifically about how the volume was specified
on `run`, assuming that if the user specified it with a name they expect
it to persist after the container is cleaned up.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
During daemon startup, all containers are registered before any are
started.
During container registration it was calling out to initialize volumes.
If the volume uses a plugin that is running in a container, this will
cause the restart of that container to fail since the plugin is not yet
running.
This also slowed down daemon startup since volume initialization was
happening sequentially, which can be slow (and is flat out slow since
initialization would fail but take 8 seconds for each volume to do it).
This fix holds off on volume initialization until after containers are
restarted and does the initialization in parallel.
The containers that are restarted will have thier volumes initialized
because they are being started. If any of these containers are using a
plugin they will just keep retrying to reach the plugin (up to the
timeout, which is 8seconds) until the container with the plugin is up
and running.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Makes `docker volume ls` and `docker volume inspect` ask the volume
drivers rather than only using what is cached locally.
Previously in order to use a volume from an external driver, one would
either have to use `docker volume create` or have a container that is
already using that volume for it to be visible to the other volume
API's.
For keeping uniqueness of volume names in the daemon, names are bound to
a driver on a first come first serve basis. If two drivers have a volume
with the same name, the first one is chosen, and a warning is logged
about the second one.
Adds 2 new methods to the plugin API, `List` and `Get`.
If a plugin does not implement these endpoints, a user will not be able
to find the specified volumes as well requests go through the drivers.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
- Make the API client library completely standalone.
- Move windows partition isolation detection to the client, so the
driver doesn't use external types.
Signed-off-by: David Calavera <david.calavera@gmail.com>
Allow passing mount propagation option shared, slave, or private as volume
property.
For example.
docker run -ti -v /root/mnt-source:/root/mnt-dest:slave fedora bash
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
So other packages don't need to import the daemon package when they
want to use this struct.
Signed-off-by: David Calavera <david.calavera@gmail.com>
Signed-off-by: Tibor Vass <tibor@docker.com>
It will Tar up contents of child directory onto tmpfs if mounted over
This patch will use the new PreMount and PostMount hooks to "tar"
up the contents of the base image on top of tmpfs mount points.
Signed-off-by: Dan Walsh <dwalsh@redhat.com>
By removing deprecated volume structures, now that windows mount volumes we don't need a initializer per platform.
Signed-off-by: David Calavera <david.calavera@gmail.com>
With the changes merged into runc/libcontainer, are now causing
SELinux to attempt a relabel always, even if the user did not
request the relabel.
If the user does not specify Z or z on the volume mount we should
not attempt a relabel.
Signed-off-by: Dan Walsh <dwalsh@redhat.com>
- Add unit tests to make sure the functionality is correct.
- Add FilterByDriver to allow filtering volumes by driver, for future
`volume ls` filtering and whatnot.
Signed-off-by: David Calavera <david.calavera@gmail.com>
Volumes are accounted when a container is created.
If the creation fails we should remove the reference from the counter.
Do not log ErrVolumeInUse as an error, having other volume references is
not an error.
Signed-off-by: David Calavera <david.calavera@gmail.com>
The following methods will deprecate the Copy method and introduce
two new, well-behaved methods for creating a tar archive of a resource
in a container and for extracting a tar archive into a directory in a
container.
Docker-DCO-1.1-Signed-off-by: Josh Hawn <josh.hawn@docker.com> (github: jlhawn)
Replaced github.com/docker/libcontainer with
github.com/opencontainers/runc/libcontaier.
Also I moved AppArmor profile generation to docker.
Main idea of this update is to fix mounting cgroups inside containers.
After updating docker on CI we can even remove dind.
Signed-off-by: Alexander Morozov <lk4d4@docker.com>
