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>
- 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)
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>
SetMaxThreads from runtime/debug in Golang is called to set max threads
value to 90% of /proc/sys/kernel/threads-max
Signed-off-by: Antonio Murdaca <runcom@redhat.com>
The restart container has already prepared the mountpoint, there is
no need to do that again. This can speed up the daemon start if
the restart container has a volume and the volume driver is not
available.
Signed-off-by: Lei Jitang <leijitang@huawei.com>
daemon cache was getting the whole image map and then iterating through
it to find children. This information is already stored in the image
store.
Prior to this change building the docker repo with a full cache took 30
seconds.
After it takes between 15 seconds or less (As low as 9 seconds).
This is an improvement on docker 1.9.1 which hovered around 17 seconds.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
During daemon startup, all containers are registered before any are
started.
During container registration it was calling out to initialize volumes.
If the volume uses a plugin that is running in a container, this will
cause the restart of that container to fail since the plugin is not yet
running.
This also slowed down daemon startup since volume initialization was
happening sequentially, which can be slow (and is flat out slow since
initialization would fail but take 8 seconds for each volume to do it).
This fix holds off on volume initialization until after containers are
restarted and does the initialization in parallel.
The containers that are restarted will have thier volumes initialized
because they are being started. If any of these containers are using a
plugin they will just keep retrying to reach the plugin (up to the
timeout, which is 8seconds) until the container with the plugin is up
and running.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Read configuration after flags making this the priority:
1- Apply configuration from file.
2- Apply configuration from flags.
Reload configuration when a signal is received, USR2 in Linux:
- Reload router if the debug configuration changes.
- Reload daemon labels.
- Reload cluster discovery.
Signed-off-by: David Calavera <david.calavera@gmail.com>
Before #16032, once links were setup
in the sqlite db, hostConfig.Links was cleared out.
This means that we need to migrate data back out of the sqlite db and
put it back into hostConfig.Links so that links specified on older
daemons can be used.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Don't rely on sqlite db for name registration and linking.
Instead register names and links when the daemon starts to an in-memory
store.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Makes `docker volume ls` and `docker volume inspect` ask the volume
drivers rather than only using what is cached locally.
Previously in order to use a volume from an external driver, one would
either have to use `docker volume create` or have a container that is
already using that volume for it to be visible to the other volume
API's.
For keeping uniqueness of volume names in the daemon, names are bound to
a driver on a first come first serve basis. If two drivers have a volume
with the same name, the first one is chosen, and a warning is logged
about the second one.
Adds 2 new methods to the plugin API, `List` and `Get`.
If a plugin does not implement these endpoints, a user will not be able
to find the specified volumes as well requests go through the drivers.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Merge was used by builder and daemon. With this commit, the builder
call has been inlined and the function moved to the daemon package,
which is the only other caller.
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>
Support restoreCustomImage for windows with a new interface to extract
the graph driver from the LayerStore.
Signed-off-by: Daniel Nephin <dnephin@docker.com>
David Calavera
Qiang Huang
Alessandro Boch
Tonis Tiigi
Lei Jitang
Arnaud Porterie
Anusha Ragunathan
Antonio Murdaca
Brian Goff
Tibor Vass
Vincent Demeester
Daniel Nephin
Jess Frazelle
Jessica Frazelle
Lukas Waslowski
Phil Estes
Michael Crosby