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>
Rather than using 2 different functions for different
types of conflicts use a bitmask to specify what
conflicts need to be checked. This allows a better way
to make exceptions.
Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
When pulling an image with content trust enabled, two references are
created: a digest reference and a tag reference. Deleting by tag
wouldn't actually remove the image, because the digest reference keeps
it alive.
This change modifies the rmi logic so that digest references don't keep
an image alive. If the last tag referencing a given image is deleted,
any digest references to it will be removed as well, so the image can
actually get deleted. This fixes the usability problem with deletions
when content trust is in use, so something like "docker pull busybox;
docker rmi busybox" will work as expected.
Signed-off-by: Aaron Lehmann <aaron.lehmann@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>
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>
Add distribution package for managing pulls and pushes. This is based on
the old code in the graph package, with major changes to work with the
new image/layer model.
Add v1 migration code.
Update registry, api/*, and daemon packages to use the reference
package's types where applicable.
Update daemon package to use image/layer/tag stores instead of the graph
package
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
When an image has multiple tags and rmi is called with force on a tag, only the single tag should be removed.
The current behavior is broken and removes all tags and the image.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
Lookup the graph parent reference to detect a builder cache miss before
looping the whole graph image index to build a parent-children tree.
Signed-off-by: Antonio Murdaca <runcom@redhat.com>
- use daemon member directly rather than through a function call
- create GetImage method for use external to deamon
Signed-off-by: Morgan Bauer <mbauer@us.ibm.com>
Although having a request ID available throughout the codebase is very
valuable, the impact of requiring a Context as an argument to every
function in the codepath of an API request, is too significant and was
not properly understood at the time of the review.
Furthermore, mixing API-layer code with non-API-layer code makes the
latter usable only by API-layer code (one that has a notion of Context).
This reverts commit de41640435, reversing
changes made to 7daeecd42d.
Signed-off-by: Tibor Vass <tibor@docker.com>
Conflicts:
api/server/container.go
builder/internals.go
daemon/container_unix.go
daemon/create.go
This reverts commit ff92f45be4, reversing
changes made to 80e31df3b6.
Reverting to make the next revert easier.
Signed-off-by: Tibor Vass <tibor@docker.com>
Avoid creating a global context object that will be used while the daemon is running.
Not only this object won't ever be garbage collected, but it won't ever be used for anything else than creating other contexts in each request. I think it's a bad practive to have something like this sprawling aroud the code.
This change removes that global object and initializes a context in the cases we don't have already one, like shutting down the server.
This also removes a bunch of context arguments from functions that did nothing with it.
Signed-off-by: David Calavera <david.calavera@gmail.com>
This PR adds a "request ID" to each event generated, the 'docker events'
stream now looks like this:
```
2015-09-10T15:02:50.000000000-07:00 [reqid: c01e3534ddca] de7c5d4ca927253cf4e978ee9c4545161e406e9b5a14617efb52c658b249174a: (from ubuntu) create
```
Note the `[reqID: c01e3534ddca]` part, that's new.
Each HTTP request will generate its own unique ID. So, if you do a
`docker build` you'll see a series of events all with the same reqID.
This allow for log processing tools to determine which events are all related
to the same http request.
I didn't propigate the context to all possible funcs in the daemon,
I decided to just do the ones that needed it in order to get the reqID
into the events. I'd like to have people review this direction first, and
if we're ok with it then I'll make sure we're consistent about when
we pass around the context - IOW, make sure that all funcs at the same level
have a context passed in even if they don't call the log funcs - this will
ensure we're consistent w/o passing it around for all calls unnecessarily.
ping @icecrime @calavera @crosbymichael
Signed-off-by: Doug Davis <dug@us.ibm.com>
This file was not well documented and had very high cyclomatic complexity.
This patch completely rearranges this file and the ImageDelete method to
be easier to follow and more maintainable in the future.
Docker-DCO-1.1-Signed-off-by: Josh Hawn <josh.hawn@docker.com> (github: jlhawn)
- some method names were changed to have a 'Locking' suffix, as the
downcased versions already existed, and the existing functions simply
had locks around the already downcased version.
- deleting unused functions
- package comment
- magic numbers replaced by golang constants
- comments all over
Signed-off-by: Morgan Bauer <mbauer@us.ibm.com>
Expand the godoc documentation for the graph package.
Centralize DefaultTag in the graphs/tag package instead of defining it
twice.
Remove some unnecessary "config" structs that are only used to pass
a few parameters to a function.
Simplify the GetParentsSize function - there's no reason for it to take
an accumulator argument.
Unexport some functions that aren't needed outside the package.
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
Move graph related functions in image to graph package.
Consolidating graph functionality is the first step in refactoring graph into an image store model.
Subsequent refactors will involve breaking up graph into multiple types with a strongly defined interface.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
I ran into a situation where I was trying:
`docker rmi busybox`
and it kept failing saying:
`could not find image: Prefix can't be empty`
While I have no idea how I got into this situation, it turns out this is
error message is from `daemon.canDeleteImage()`. In that func we loop over
all containers checking to see if they're using the image we're trying to
delete. In my case though, I had a container with no ImageID. So the code
would die tryig to find that image (hence the "Prefix can't be empty" err).
This would stop all processing despite the fact that the container we're
checking had nothing to do with 'busybox'.
My change logs the bad situation in the logs and then skips that container.
There's no reason to fail all `docker rmi ...` calls just because of one
bad container.
Will continue to try to figure out how I got a container w/o an ImageID
but as of now I have no idea, I didn't do anything but normal docker cli
commands.
Signed-off-by: Doug Davis <dug@us.ibm.com>
If an image has been tagged to multiple repos and tags, 'docker
rmi -f IMAGE_ID' will just untag one random repo instead of
untagging all and deleting the image. This patch implement
this. This commit is composed of:
*untag all names and delete the image
*add test to this feature
*modify commandline/cli.md to explain this
Signed-off-by: Deng Guangxing <dengguangxing@huawei.com>
Add ability to refer to an image by repository name and digest using the
format repository@digest. Works for pull, push, run, build, and rmi.
Signed-off-by: Andy Goldstein <agoldste@redhat.com>
See: https://github.com/docker/docker/issues/10867
While looking at #10867 I noticed that the error message generated for
a blank image ID wasn't very helpful so this fixes that.
Signed-off-by: Doug Davis <dug@us.ibm.com>
