Instead of having to create a bunch of custom error types that are doing
nothing but wrapping another error in sub-packages, use a common helper
to create errors of the requested type.
e.g. instead of re-implementing this over and over:
```go
type notFoundError struct {
cause error
}
func(e notFoundError) Error() string {
return e.cause.Error()
}
func(e notFoundError) NotFound() {}
func(e notFoundError) Cause() error {
return e.cause
}
```
Packages can instead just do:
```
errdefs.NotFound(err)
```
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Upstream-commit: 87a12421a94faac294079bebc97c8abb4180dde5
Component: engine
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>
Upstream-commit: ebcb7d6b406fe50ea9a237c73004d75884184c33
Component: engine
These errors were producing the wrong status code,
changing to 503.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Upstream-commit: 7e44fffe40f39ef4cc0b3bee810f7d0a26136376
Component: engine
When swarm-mode is disabled, we need to return an error indicating this.
406 was chosen for the "Not Acceptable" verbiage, but this code has
specific semantics in relation to the `Accept` header, which aren't
applicable here.
We now use a 503 for this case. While it is not a perfect match, it does
make it clear that the particular "service" (read: API endpoint) is not
available. The body of the message provides the user with enough
information to take action on it by enabling swarm-mode and ensuring the
service is available.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
Upstream-commit: 1d90d7604881e29b71819af9c092d565513aeeec
Component: engine
Error code resolution is powered by string matching. Not the greatest
thing in the world and I hope no one is proud of this code, but it
works. However, because a map is used, the iteration order of the map is
random, such that if an error matches two of the snippets, it may return
a different error code depending on the seed of the hashmap. This change
converts it to use a slice instead.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
Upstream-commit: 3484e02590117d175d9c1ab24c583390b4e94a55
Component: engine
This moves the types for the `engine-api` repo to the existing types
package.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
Upstream-commit: 91e197d614547f0202e6ae9b8a24d88ee131d950
Component: engine
As described in our ROADMAP.md, introduce new Swarm management API
endpoints relying on swarmkit to deploy services. It currently vendors
docker/engine-api changes.
This PR is fully backward compatible (joining a Swarm is an optional
feature of the Engine, and existing commands are not impacted).
Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
Signed-off-by: Victor Vieux <vieux@docker.com>
Signed-off-by: Daniel Nephin <dnephin@docker.com>
Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
Signed-off-by: Madhu Venugopal <madhu@docker.com>
Upstream-commit: 534a90a99367af6f6bba1ddcc7eb07506e41f774
Component: engine
This functionality has been fixed by
7bca93218291767c5dd8782de0ad630dbcda9995 but then it has been broken
again by a793564b2591035aec5412fbcbcccf220c773a4c and finally refixed
here.
Basically the functionality was to prompt for login when trying to pull
from the official docker hub.
Signed-off-by: Antonio Murdaca <runcom@redhat.com>
Upstream-commit: 4316ae2ed33d158e1d8d994646a75e25a70d9320
Component: engine
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>
Upstream-commit: a793564b2591035aec5412fbcbcccf220c773a4c
Component: engine
