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moby--moby/errdefs/http_helpers.go

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package errdefs // import "github.com/docker/docker/errdefs"
Remove static errors from errors package. 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>
2016-02-25 10:53:35 -05:00
import (
"fmt"
Remove static errors from errors package. 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>
2016-02-25 10:53:35 -05:00
"net/http"
Handle correct status codes for distribution errors This assists to address a regression where distribution errors were not properly handled, resulting in a generic 500 (internal server error) to be returned for `/distribution/name/json` if you weren't authenticated, whereas it should return a 40x (401). This patch attempts to extract the HTTP status-code that was returned by the distribution code, and falls back to returning a 500 status if unable to match. Before this change: curl -v --unix-socket /var/run/docker.sock http://localhost/distribution/name/json * Trying /var/run/docker.sock... * Connected to localhost (/var/run/docker.sock) port 80 (#0) > GET /distribution/name/json HTTP/1.1 > Host: localhost > User-Agent: curl/7.52.1 > Accept: */* > < HTTP/1.1 500 Internal Server Error < Api-Version: 1.37 < Content-Type: application/json < Docker-Experimental: false < Ostype: linux < Server: Docker/dev (linux) < Date: Tue, 03 Jul 2018 15:52:53 GMT < Content-Length: 115 < {"message":"errors:\ndenied: requested access to the resource is denied\nunauthorized: authentication required\n"} * Curl_http_done: called premature == 0 * Connection #0 to host localhost left intact daemon logs: DEBU[2018-07-03T15:52:51.424950601Z] Calling GET /distribution/name/json DEBU[2018-07-03T15:52:53.179895572Z] FIXME: Got an API for which error does not match any expected type!!!: errors: denied: requested access to the resource is denied unauthorized: authentication required error_type=errcode.Errors module=api ERRO[2018-07-03T15:52:53.179942783Z] Handler for GET /distribution/name/json returned error: errors: denied: requested access to the resource is denied unauthorized: authentication required With this patch applied: curl -v --unix-socket /var/run/docker.sock http://localhost/distribution/name/json * Trying /var/run/docker.sock... * Connected to localhost (/var/run/docker.sock) port 80 (#0) > GET /distribution/name/json HTTP/1.1 > Host: localhost > User-Agent: curl/7.52.1 > Accept: */* > < HTTP/1.1 403 Forbidden < Api-Version: 1.38 < Content-Type: application/json < Docker-Experimental: false < Ostype: linux < Server: Docker/dev (linux) < Date: Fri, 03 Aug 2018 14:58:09 GMT < Content-Length: 115 < {"message":"errors:\ndenied: requested access to the resource is denied\nunauthorized: authentication required\n"} * Curl_http_done: called premature == 0 * Connection #0 to host localhost left intact daemon logs: DEBU[2018-08-03T14:58:08.018726228Z] Calling GET /distribution/name/json Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2018-08-03 10:41:47 -04:00
"github.com/docker/distribution/registry/api/errcode"
"github.com/sirupsen/logrus"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/status"
Remove static errors from errors package. 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>
2016-02-25 10:53:35 -05:00
)
// GetHTTPErrorStatusCode retrieves status code from error message.
func GetHTTPErrorStatusCode(err error) int {
if err == nil {
logrus.WithFields(logrus.Fields{"error": err}).Error("unexpected HTTP error handling")
return http.StatusInternalServerError
Remove static errors from errors package. 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>
2016-02-25 10:53:35 -05:00
}
var statusCode int
// Stop right there
// Are you sure you should be adding a new error class here? Do one of the existing ones work?
// Note that the below functions are already checking the error causal chain for matches.
switch {
case IsNotFound(err):
statusCode = http.StatusNotFound
case IsInvalidParameter(err):
Remove static errors from errors package. 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>
2016-02-25 10:53:35 -05:00
statusCode = http.StatusBadRequest
case IsConflict(err):
statusCode = http.StatusConflict
case IsUnauthorized(err):
statusCode = http.StatusUnauthorized
case IsUnavailable(err):
statusCode = http.StatusServiceUnavailable
case IsForbidden(err):
statusCode = http.StatusForbidden
case IsNotModified(err):
statusCode = http.StatusNotModified
case IsNotImplemented(err):
statusCode = http.StatusNotImplemented
case IsSystem(err) || IsUnknown(err) || IsDataLoss(err) || IsDeadline(err) || IsCancelled(err):
statusCode = http.StatusInternalServerError
Remove static errors from errors package. 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>
2016-02-25 10:53:35 -05:00
default:
statusCode = statusCodeFromGRPCError(err)
if statusCode != http.StatusInternalServerError {
return statusCode
}
Handle correct status codes for distribution errors This assists to address a regression where distribution errors were not properly handled, resulting in a generic 500 (internal server error) to be returned for `/distribution/name/json` if you weren't authenticated, whereas it should return a 40x (401). This patch attempts to extract the HTTP status-code that was returned by the distribution code, and falls back to returning a 500 status if unable to match. Before this change: curl -v --unix-socket /var/run/docker.sock http://localhost/distribution/name/json * Trying /var/run/docker.sock... * Connected to localhost (/var/run/docker.sock) port 80 (#0) > GET /distribution/name/json HTTP/1.1 > Host: localhost > User-Agent: curl/7.52.1 > Accept: */* > < HTTP/1.1 500 Internal Server Error < Api-Version: 1.37 < Content-Type: application/json < Docker-Experimental: false < Ostype: linux < Server: Docker/dev (linux) < Date: Tue, 03 Jul 2018 15:52:53 GMT < Content-Length: 115 < {"message":"errors:\ndenied: requested access to the resource is denied\nunauthorized: authentication required\n"} * Curl_http_done: called premature == 0 * Connection #0 to host localhost left intact daemon logs: DEBU[2018-07-03T15:52:51.424950601Z] Calling GET /distribution/name/json DEBU[2018-07-03T15:52:53.179895572Z] FIXME: Got an API for which error does not match any expected type!!!: errors: denied: requested access to the resource is denied unauthorized: authentication required error_type=errcode.Errors module=api ERRO[2018-07-03T15:52:53.179942783Z] Handler for GET /distribution/name/json returned error: errors: denied: requested access to the resource is denied unauthorized: authentication required With this patch applied: curl -v --unix-socket /var/run/docker.sock http://localhost/distribution/name/json * Trying /var/run/docker.sock... * Connected to localhost (/var/run/docker.sock) port 80 (#0) > GET /distribution/name/json HTTP/1.1 > Host: localhost > User-Agent: curl/7.52.1 > Accept: */* > < HTTP/1.1 403 Forbidden < Api-Version: 1.38 < Content-Type: application/json < Docker-Experimental: false < Ostype: linux < Server: Docker/dev (linux) < Date: Fri, 03 Aug 2018 14:58:09 GMT < Content-Length: 115 < {"message":"errors:\ndenied: requested access to the resource is denied\nunauthorized: authentication required\n"} * Curl_http_done: called premature == 0 * Connection #0 to host localhost left intact daemon logs: DEBU[2018-08-03T14:58:08.018726228Z] Calling GET /distribution/name/json Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2018-08-03 10:41:47 -04:00
statusCode = statusCodeFromDistributionError(err)
if statusCode != http.StatusInternalServerError {
return statusCode
}
if e, ok := err.(causer); ok {
return GetHTTPErrorStatusCode(e.Cause())
Remove static errors from errors package. 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>
2016-02-25 10:53:35 -05:00
}
logrus.WithFields(logrus.Fields{
"module": "api",
"error_type": fmt.Sprintf("%T", err),
}).Debugf("FIXME: Got an API for which error does not match any expected type!!!: %+v", err)
Remove static errors from errors package. 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>
2016-02-25 10:53:35 -05:00
}
if statusCode == 0 {
statusCode = http.StatusInternalServerError
}
return statusCode
}
// FromStatusCode creates an errdef error, based on the provided HTTP status-code
func FromStatusCode(err error, statusCode int) error {
if err == nil {
return err
}
switch statusCode {
case http.StatusNotFound:
err = NotFound(err)
case http.StatusBadRequest:
err = InvalidParameter(err)
case http.StatusConflict:
err = Conflict(err)
case http.StatusUnauthorized:
err = Unauthorized(err)
case http.StatusServiceUnavailable:
err = Unavailable(err)
case http.StatusForbidden:
err = Forbidden(err)
case http.StatusNotModified:
err = NotModified(err)
case http.StatusNotImplemented:
err = NotImplemented(err)
case http.StatusInternalServerError:
if !IsSystem(err) && !IsUnknown(err) && !IsDataLoss(err) && !IsDeadline(err) && !IsCancelled(err) {
err = System(err)
}
default:
logrus.WithFields(logrus.Fields{
"module": "api",
"status_code": fmt.Sprintf("%d", statusCode),
}).Debugf("FIXME: Got an status-code for which error does not match any expected type!!!: %d", statusCode)
switch {
case statusCode >= 200 && statusCode < 400:
// it's a client error
case statusCode >= 400 && statusCode < 500:
err = InvalidParameter(err)
case statusCode >= 500 && statusCode < 600:
err = System(err)
default:
err = Unknown(err)
}
}
return err
}
// statusCodeFromGRPCError returns status code according to gRPC error
func statusCodeFromGRPCError(err error) int {
switch status.Code(err) {
case codes.InvalidArgument: // code 3
return http.StatusBadRequest
case codes.NotFound: // code 5
return http.StatusNotFound
case codes.AlreadyExists: // code 6
return http.StatusConflict
case codes.PermissionDenied: // code 7
return http.StatusForbidden
case codes.FailedPrecondition: // code 9
return http.StatusBadRequest
case codes.Unauthenticated: // code 16
return http.StatusUnauthorized
case codes.OutOfRange: // code 11
return http.StatusBadRequest
case codes.Unimplemented: // code 12
return http.StatusNotImplemented
case codes.Unavailable: // code 14
return http.StatusServiceUnavailable
default:
if e, ok := err.(causer); ok {
return statusCodeFromGRPCError(e.Cause())
}
// codes.Canceled(1)
// codes.Unknown(2)
// codes.DeadlineExceeded(4)
// codes.ResourceExhausted(8)
// codes.Aborted(10)
// codes.Internal(13)
// codes.DataLoss(15)
return http.StatusInternalServerError
}
}
Handle correct status codes for distribution errors This assists to address a regression where distribution errors were not properly handled, resulting in a generic 500 (internal server error) to be returned for `/distribution/name/json` if you weren't authenticated, whereas it should return a 40x (401). This patch attempts to extract the HTTP status-code that was returned by the distribution code, and falls back to returning a 500 status if unable to match. Before this change: curl -v --unix-socket /var/run/docker.sock http://localhost/distribution/name/json * Trying /var/run/docker.sock... * Connected to localhost (/var/run/docker.sock) port 80 (#0) > GET /distribution/name/json HTTP/1.1 > Host: localhost > User-Agent: curl/7.52.1 > Accept: */* > < HTTP/1.1 500 Internal Server Error < Api-Version: 1.37 < Content-Type: application/json < Docker-Experimental: false < Ostype: linux < Server: Docker/dev (linux) < Date: Tue, 03 Jul 2018 15:52:53 GMT < Content-Length: 115 < {"message":"errors:\ndenied: requested access to the resource is denied\nunauthorized: authentication required\n"} * Curl_http_done: called premature == 0 * Connection #0 to host localhost left intact daemon logs: DEBU[2018-07-03T15:52:51.424950601Z] Calling GET /distribution/name/json DEBU[2018-07-03T15:52:53.179895572Z] FIXME: Got an API for which error does not match any expected type!!!: errors: denied: requested access to the resource is denied unauthorized: authentication required error_type=errcode.Errors module=api ERRO[2018-07-03T15:52:53.179942783Z] Handler for GET /distribution/name/json returned error: errors: denied: requested access to the resource is denied unauthorized: authentication required With this patch applied: curl -v --unix-socket /var/run/docker.sock http://localhost/distribution/name/json * Trying /var/run/docker.sock... * Connected to localhost (/var/run/docker.sock) port 80 (#0) > GET /distribution/name/json HTTP/1.1 > Host: localhost > User-Agent: curl/7.52.1 > Accept: */* > < HTTP/1.1 403 Forbidden < Api-Version: 1.38 < Content-Type: application/json < Docker-Experimental: false < Ostype: linux < Server: Docker/dev (linux) < Date: Fri, 03 Aug 2018 14:58:09 GMT < Content-Length: 115 < {"message":"errors:\ndenied: requested access to the resource is denied\nunauthorized: authentication required\n"} * Curl_http_done: called premature == 0 * Connection #0 to host localhost left intact daemon logs: DEBU[2018-08-03T14:58:08.018726228Z] Calling GET /distribution/name/json Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2018-08-03 10:41:47 -04:00
// statusCodeFromDistributionError returns status code according to registry errcode
// code is loosely based on errcode.ServeJSON() in docker/distribution
func statusCodeFromDistributionError(err error) int {
switch errs := err.(type) {
case errcode.Errors:
if len(errs) < 1 {
return http.StatusInternalServerError
}
if _, ok := errs[0].(errcode.ErrorCoder); ok {
return statusCodeFromDistributionError(errs[0])
}
case errcode.ErrorCoder:
return errs.ErrorCode().Descriptor().HTTPStatusCode
default:
if e, ok := err.(causer); ok {
return statusCodeFromDistributionError(e.Cause())
}
}
return http.StatusInternalServerError
}