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>
The execdriver pipes setup uses OS pipes with fds so that they can be
chown'ed to the remapped root user for proper access. Recent flakiness
in certain short-lived tests (usually via the "exec" path) reveals that
the copy routines are not completing before exit/tear-down.
This fix adds synchronization and proper closure such that these
routines exit successfully.
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
This enhancement is to fix the wrong list results on
`docker ps` before and since filters specifying the non-running container.
Fixes issue #20431
Signed-off-by: Wen Cheng Ma <wenchma@cn.ibm.com>
Because devices will be bind-mounted instead of using `mknod`, we need
to make sure the source exists and filter the list by only those whose
source is a valid path/current device entry.
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
There are five options 'debug' 'labels' 'cluster-store' 'cluster-store-opts'
and 'cluster-advertise' that can be reconfigured, configure any of these
options should not affect other options which may have configured in flags.
But this is not true, for example, I start a daemon with -D to enable the
debugging, and after a while, I want reconfigure the 'label', so I add a file
'/etc/docker/daemon.json' with content '"labels":["test"]' and send SIGHUP to daemon
to reconfigure the daemon, it work, but the debugging of the daemon is also diabled.
I don't think this is a expeted behaviour.
This patch also have some minor refactor of reconfiguration of cluster-advertiser.
Enable user to reconfigure cluster-advertiser without cluster-store in config file
since cluster-store could also be already set in flag, and we only want to reconfigure
the cluster-advertiser.
Signed-off-by: Lei Jitang <leijitang@huawei.com>
- Allow to filter containers by volume with `--filter volume=name` and `filter volume=/dest`.
- Show their names in the list with the custom format `{{ .Mounts }}`.
Signed-off-by: David Calavera <david.calavera@gmail.com>
Add `--restart` flag for `update` command, so we can change restart
policy for a container no matter it's running or stopped.
Signed-off-by: Zhang Wei <zhangwei555@huawei.com>
When the value for a configuration option in the file is `false`,
and the default value for a flag is `true`, we should not
take the value from the later as final value for the option,
because the user explicitly set `false`.
This change overrides the default value in the flagSet with
the value in the configuration file so we get the correct
result when we merge the two configurations together.
Signed-off-by: David Calavera <david.calavera@gmail.com>
This corrects `docker cp` behavior when user namespaces are enabled.
Instead of chown'ing copied-in files to real root (0,0), the code
queries for the remapped root uid & gid and sets the chown option
properly.
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
- It reverts fa163f5619 plus a small change
in order to allow passing the global scope datastore
to libnetwork after damon boot.
Signed-off-by: Alessandro Boch <aboch@docker.com>
Also changes missing storage layer for container
RWLayer to a soft failure.
Fixes#20147
Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
(cherry picked from commit 2798d7a6a681aee8995e87c9b68128e54876d2b5)
