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>
duplicate dot in user namespaces error message:
$ docker run -ti --net=host ubuntu /bin/bash
docker: Error response from daemon: Cannot share the host or a
container's network namespace when user namespaces are enabled..
Signed-off-by: Liron Levin <liron@twistlock.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>
dockerinit has been around for a very long time. It was originally used
as a way for us to do configuration for LXC containers once the
container had started. LXC is no longer supported, and /.dockerinit has
been dead code for quite a while. This removes all code and references
in code to dockerinit.
Signed-off-by: Aleksa Sarai <asarai@suse.com>
Instead of warning the caller who is disabling OOM killer that the
feature isn't available, only warn if they are trying to **enable** OOM
killer and it can't be done.
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
Fixes: #19278
The issue seems existed since we add support for OomKillDisable,
OomKillDisable support should not be hard request, we just
discard it if not support and move on.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
This brings in the container-local alias functionality for containers
connected to u ser-defined networks.
Signed-off-by: Madhu Venugopal <madhu@docker.com>
It's like `MemorySwappiness`, the default value has specific
meaning (default false means enable oom kill).
We need to change it to pointer so we can update it after
container is created.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
(cherry picked from commit 9c2ea42329)
Conflicts:
vendor/src/github.com/docker/engine-api/types/container/host_config.go
- In case --fixed-cidr-v6 is specified and docker0 bridge already
has a global scope IPv6 address belonging to that v6 network
(likely from a previous daemon instance), to maintain consistency
with what done for the docker0 IPv4 address, daemon has to pass it
down to libnetwork in the IPAMConfig as network gateway to make
sure that the address is not given to some container.
Signed-off-by: Alessandro Boch <aboch@docker.com>
This prevents strange errors and clarifies which namespace options are
incompatible with user namespaces (at this time).
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
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>
dockerfile.Config is almost redundant with ImageBuildOptions.
Unify the two so that the latter can be removed. This also
helps build's API endpoint code to be less dependent on package
dockerfile.
Signed-off-by: Anusha Ragunathan <anusha@docker.com>
The parse.go file is used almost exclusively in the client. The few small
functions that are used outside of the client could easily be copied out
when the client is extracted, allowing this runconfig/opts package to
move to the client.
Signed-off-by: Daniel Nephin <dnephin@docker.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>
- Make the API client library completely standalone.
- Move windows partition isolation detection to the client, so the
driver doesn't use external types.
Signed-off-by: David Calavera <david.calavera@gmail.com>
1. It's a cgroup api, fit the general defination that we take
cgroup options as kind of resource options.
2. It's common usage and very helpful as explained here:
https://github.com/docker/docker/pull/18270#issuecomment-160561316
3. It's already in `Resource` struct in
daemon/execdriver/driver_unix.go
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
This solves a bug where /etc may have pre-existing permissions from
build time, but init layer setup (reworked for user namespaces) was
assuming root ownership. Adds a test as well to catch this situation in
the future.
Minor fix to wrong ordering of chown/close on files created during the
same initlayer setup.
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
So other packages don't need to import the daemon package when they
want to use this struct.
Signed-off-by: David Calavera <david.calavera@gmail.com>
Signed-off-by: Tibor Vass <tibor@docker.com>
