Use strongly typed errors to set HTTP status codes.
Error interfaces are defined in the api/errors package and errors
returned from controllers are checked against these interfaces.
Errors can be wraeped in a pkg/errors.Causer, as long as somewhere in the
line of causes one of the interfaces is implemented. The special error
interfaces take precedence over Causer, meaning if both Causer and one
of the new error interfaces are implemented, the Causer is not
traversed.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Reuse existing structures and rely on json serialization to deep copy
Container objects.
Also consolidate all "save" operations on container.CheckpointTo, which
now both saves a serialized json to disk, and replicates state to the
ACID in-memory store.
Signed-off-by: Fabio Kung <fabio.kung@gmail.com>
Replicate relevant mutations to the in-memory ACID store. Readers will
then be able to query container state without locking.
Signed-off-by: Fabio Kung <fabio.kung@gmail.com>
Kernel memory is not allowed to be updated if container is
running, it's not actually a precise kernel limitation.
Before kernel version 4.6, kernel memory will not be accounted
until kernel memory limit is set, if a container created with
kernel memory initialized, kernel memory is accounted as soon
as process created in container, so kernel memory limit update
is allowed afterward. If kernel memory is not initialized,
kernel memory consumed by processes in container will not be
accounted, so we can't update the limit because the account
will be wrong.
So update kernel memory of a running container with kernel memory
initialized is allowed, we should soften the limitation by docker.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
In order to keep a little bit of "sanity" on the API side, validate
hostname only starting from v1.24 API version.
Signed-off-by: Vincent Demeester <vincent@sbr.pm>
Remove function `WaitRunning` because it's actually not necessary, also
remove wait channel for state "running" to avoid mixed use of the state
wait channel.
Signed-off-by: Zhang Wei <zhangwei555@huawei.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>
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>
Currently some commands including `kill`, `pause`, `restart`, `rm`,
`rmi`, `stop`, `unpause`, `udpate`, `wait` will print a lot of error
message on client side, with a lot of redundant messages, this commit is
trying to remove the unuseful and redundant information for user.
Signed-off-by: Zhang Wei <zhangwei555@huawei.com>
Currently, daemonbuilder package (part of daemon) implemented the
builder backend. However, it was a very thin wrapper around daemon
methods and caused an implementation dependency for api/server build
endpoint. api/server buildrouter should only know about the backend
implementing the /build API endpoint.
Removing daemonbuilder involved moving build specific methods to
respective files in the daemon, where they fit naturally.
Signed-off-by: Anusha Ragunathan <anusha@docker.com>
- Stop serializing JSONMessage in favor of events.Message.
- Keep backwards compatibility with JSONMessage for container events.
Signed-off-by: David Calavera <david.calavera@gmail.com>
It's used for updating properties of one or more containers, we only
support resource configs for now. It can be extended in the future.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
