NOTE should be lowercase
Signed-off-by: Ryan Wallner <ryan.wallner@clusterhq.com>
add link to list of plugins
Signed-off-by: Ryan Wallner <ryan.wallner@clusterhq.com>
address changres
Signed-off-by: Ryan Wallner <ryan.wallner@clusterhq.com>
Subscribe to events and monitor for new containers before the initial
listing of currently running containers.
This fixes a race where a new container could appear between the first
list call but before the client was subscribed to events, leading to a
container never appearing in the output of `docker stats`.
Signed-off-by: Arnaud Porterie <arnaud.porterie@docker.com>
* users don't have to create an google account for using the google groups. They
can simply email to e.g. "docker-user+subscribe@googlegroups.com" to
subscribe.
* since this behavior is not mentioned on the google group website, i think its
a good idea to explain this method here.
Signed-off-by: toogley <toogley@mailbox.org>
This improves on an earlier change by adding another keyserver and using a for loop instead of duplicating the command
Signed-off-by: Mike Dougherty <mike.dougherty@docker.com>
Stop using global variables as prefixes to inject the writer header.
That can cause issues when two writers set the length of the buffer in
the same header concurrently.
Stop Writing to the internal buffer twice for each write. This could
mess up with the ordering information is written.
Signed-off-by: David Calavera <david.calavera@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>
Sebastiaan van Stijn
Vincent Demeester
Tibor Vass
Linus Heckemann
Ryan Wallner
Brian Goff
Qiang Huang
Linus Heckemann
terryding77
Antonio Murdaca
John Howard
Arnaud Porterie
Pavel Sutyrin
toogley
Antonio Murdaca
Alexander Morozov
Mike Dougherty
Christian Böhme
David Calavera
Tianon Gravi
Alexander Morozov