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>
If user specifies --read-only flag it should not effect /dev/mqueue.
This is causing SELinux issues in docker-1.10. --read-only blows up
on SELinux enabled machines. Mounting /dev/mqueue read/only would also
blow up any tool that was going to use /dev/mqueue.
Signed-off-by: Dan Walsh <dwalsh@redhat.com>
We cannot rely on the tar command for this type of operation because tar
versions, flags, and functionality can very from distro to distro.
Since this is in the container execution path it is not safe to have
this as a dependency from dockers POV where the user cannot change the
fact that docker is adding these pre and post mount commands.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
Whether a shared/slave volume propagation will work or not also depends on
where source directory is mounted on and what are the propagation properties
of that mount point. For example, for shared volume mount to work, source
mount point should be shared. For slave volume mount to work, source mount
point should be either shared/slave.
This patch determines the mount point on which directory is mounted and
checks for desired minimum propagation properties of that mount point. It
errors out of configuration does not seem right.
Signed-off-by: Vivek Goyal <vgoyal@redhat.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>
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>
libcontainer v0.0.4 introduces setting `/proc/self/oom_score_adj` to
better tune oom killing preferences for container process. This patch
simply integrates OomScoreAdj libcontainer's config option and adjust
the cli with this new option.
Signed-off-by: Antonio Murdaca <amurdaca@redhat.com>
Signed-off-by: Antonio Murdaca <runcom@redhat.com>
Adds support for the daemon to handle user namespace maps as a
per-daemon setting.
Support for handling uid/gid mapping is added to the builder,
archive/unarchive packages and functions, all graphdrivers (except
Windows), and the test suite is updated to handle user namespace daemon
rootgraph changes.
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
Although having a request ID available throughout the codebase is very
valuable, the impact of requiring a Context as an argument to every
function in the codepath of an API request, is too significant and was
not properly understood at the time of the review.
Furthermore, mixing API-layer code with non-API-layer code makes the
latter usable only by API-layer code (one that has a notion of Context).
This reverts commit de41640435, reversing
changes made to 7daeecd42d.
Signed-off-by: Tibor Vass <tibor@docker.com>
Conflicts:
api/server/container.go
builder/internals.go
daemon/container_unix.go
daemon/create.go
This PR adds a "request ID" to each event generated, the 'docker events'
stream now looks like this:
```
2015-09-10T15:02:50.000000000-07:00 [reqid: c01e3534ddca] de7c5d4ca927253cf4e978ee9c4545161e406e9b5a14617efb52c658b249174a: (from ubuntu) create
```
Note the `[reqID: c01e3534ddca]` part, that's new.
Each HTTP request will generate its own unique ID. So, if you do a
`docker build` you'll see a series of events all with the same reqID.
This allow for log processing tools to determine which events are all related
to the same http request.
I didn't propigate the context to all possible funcs in the daemon,
I decided to just do the ones that needed it in order to get the reqID
into the events. I'd like to have people review this direction first, and
if we're ok with it then I'll make sure we're consistent about when
we pass around the context - IOW, make sure that all funcs at the same level
have a context passed in even if they don't call the log funcs - this will
ensure we're consistent w/o passing it around for all calls unnecessarily.
ping @icecrime @calavera @crosbymichael
Signed-off-by: Doug Davis <dug@us.ibm.com>
Using @mavenugo's patch for enabling the libcontainer pre-start hook to
be used for network namespace initialization (correcting the conflict
with user namespaces); updated the boolean check to the more generic
SupportsHooks() name, and fixed the hook state function signature.
Signed-off-by: Madhu Venugopal <madhu@docker.com>
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
Integration tests were failing due to proc filter behavior
changes with new apparmor policies.
Also include the missing docker-unconfined policy resolving
potential startup errors. This policy is complain-only so
it should behave identically to the standard unconfined policy,
but will not apply system path-based policies within containers.
Signed-off-by: Eric Windisch <eric@windisch.us>
By using the 'unconfined' policy for privileged
containers, we have inherited the host's apparmor
policies, which really make no sense in the
context of the container's filesystem.
For instance, policies written against
the paths of binaries such as '/usr/sbin/tcpdump'
can be easily circumvented by moving the binary
within the container filesystem.
Fixes GH#5490
Signed-off-by: Eric Windisch <eric@windisch.us>
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>
If a container is read-only, also set /proc, /sys,
& /dev to read-only. This should apply to both privileged and
unprivileged containers.
Note that when /dev is read-only, device files may still be
written to. This change will simply prevent the device paths
from being modified, or performing mknod of new devices within
the /dev path.
Tests are included for all cases. Also adds a test to ensure
that /dev/pts is always mounted read/write, even in the case of a
read-write rootfs. The kernel restricts writes here naturally and
bad things will happen if we mount it ro.
Signed-off-by: Eric Windisch <eric@windisch.us>
* Don't AllocateNetwork when network is disabled
* Don't createNetwork in execdriver when network is disabled
Signed-off-by: Alexander Morozov <lk4d4@docker.com>
- Updated Dockerfile to satisfy libnetwork GOPATH requirements.
- Reworked daemon to allocate network resources using libnetwork.
- Reworked remove link code to also update network resources in libnetwork.
- Adjusted the exec driver command population to reflect libnetwork design.
- Adjusted the exec driver create command steps.
- Updated a few test cases to reflect the change in design.
- Removed the dns setup code from docker as resolv.conf is entirely managed
in libnetwork.
- Integrated with lxc exec driver.
Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
Add tests for mounting into /proc and /sys
These two locations should be prohibited from mounting volumes into
those destinations.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
The `--userland-proxy` daemon flag makes it possible to rely on hairpin
NAT and additional iptables routes instead of userland proxy for port
publishing and inter-container communication.
Usage of the userland proxy remains the default as hairpin NAT is
unsupported by older kernels.
Signed-off-by: Arnaud Porterie <arnaud.porterie@docker.com>
container.
docker run -v /dev:/dev should stop mounting other default mounts in i
libcontainer otherwise directories and devices like /dev/ptx get mishandled.
We want to be able to run libvirtd for launching vms and it needs
access to the hosts /dev. This is a key componant of OpenStack.
Docker-DCO-1.1-Signed-off-by: Dan Walsh <dwalsh@redhat.com> (github: rhatdan)
David Calavera
Jessica Frazelle
Dan Walsh
Joey Geiger
Arnaud Porterie
Michael Crosby
Srini Brahmaroutu
Brian Goff
Vivek Goyal
Justas Brazauskas
Antonio Murdaca
Alexander Morozov
Phil Estes
Deng Guangxing
Tibor Vass
Mrunal Patel
Doug Davis
Hu Keping
Madhu Venugopal
Eric Windisch
Qiang Huang
Alexander Morozov
Jana Radhakrishnan
Darren Shepherd
Jessie Frazelle
Antonio Murdaca
Abin Shahab