This repository is not yet a module (i.e., does not have a `go.mod`). This
is not problematic when building the code in GOPATH or "vendor" mode, but
when using the code as a module-dependency (in module-mode), different semantics
are applied since Go1.21, which switches Go _language versions_ on a per-module,
per-package, or even per-file base.
A condensed summary of that logic [is as follows][1]:
- For modules that have a go.mod containing a go version directive; that
version is considered a minimum _required_ version (starting with the
go1.19.13 and go1.20.8 patch releases: before those, it was only a
recommendation).
- For dependencies that don't have a go.mod (not a module), go language
version go1.16 is assumed.
- Likewise, for modules that have a go.mod, but the file does not have a
go version directive, go language version go1.16 is assumed.
- If a go.work file is present, but does not have a go version directive,
language version go1.17 is assumed.
When switching language versions, Go _downgrades_ the language version,
which means that language features (such as generics, and `any`) are not
available, and compilation fails. For example:
# github.com/docker/cli/cli/context/store
/go/pkg/mod/github.com/docker/cli@v25.0.0-beta.2+incompatible/cli/context/store/storeconfig.go:6:24: predeclared any requires go1.18 or later (-lang was set to go1.16; check go.mod)
/go/pkg/mod/github.com/docker/cli@v25.0.0-beta.2+incompatible/cli/context/store/store.go:74:12: predeclared any requires go1.18 or later (-lang was set to go1.16; check go.mod)
Note that these fallbacks are per-module, per-package, and can even be
per-file, so _(indirect) dependencies_ can still use modern language
features, as long as their respective go.mod has a version specified.
Unfortunately, these failures do not occur when building locally (using
vendor / GOPATH mode), but will affect consumers of the module.
Obviously, this situation is not ideal, and the ultimate solution is to
move to go modules (add a go.mod), but this comes with a non-insignificant
risk in other areas (due to our complex dependency tree).
We can revert to using go1.16 language features only, but this may be
limiting, and may still be problematic when (e.g.) matching signatures
of dependencies.
There is an escape hatch: adding a `//go:build` directive to files that
make use of go language features. From the [go toolchain docs][2]:
> The go line for each module sets the language version the compiler enforces
> when compiling packages in that module. The language version can be changed
> on a per-file basis by using a build constraint.
>
> For example, a module containing code that uses the Go 1.21 language version
> should have a `go.mod` file with a go line such as `go 1.21` or `go 1.21.3`.
> If a specific source file should be compiled only when using a newer Go
> toolchain, adding `//go:build go1.22` to that source file both ensures that
> only Go 1.22 and newer toolchains will compile the file and also changes
> the language version in that file to Go 1.22.
This patch adds `//go:build` directives to those files using recent additions
to the language. It's currently using go1.19 as version to match the version
in our "vendor.mod", but we can consider being more permissive ("any" requires
go1.18 or up), or more "optimistic" (force go1.21, which is the version we
currently use to build).
For completeness sake, note that any file _without_ a `//go:build` directive
will continue to use go1.16 language version when used as a module.
[1]: 58c28ba286/src/cmd/go/internal/gover/version.go (L9-L56)
[2]: https://go.dev/doc/toolchain
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Allow SetMatrix to be used as a value type with a ready-to-use zero
value. SetMatrix values are already non-copyable by virtue of having a
mutex field so there is no harm in allowing non-pointer values to be
used as local variables or struct fields. Any attempts to pass around
by-value copies, e.g. as function arguments, will be flagged by go vet.
Signed-off-by: Cory Snider <csnider@mirantis.com>
After moving libnetwork to this repo, we need to update all the import
paths for libnetwork to point to docker/docker/libnetwork instead of
docker/libnetwork.
This change implements that.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Internal directory is designed to contain libraries
that are exclusively used by this project
Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>
This patch attempts to allow endpoints to complete servicing connections
while being removed from a service. The change adds a flag to the
endpoint.deleteServiceInfoFromCluster() method to indicate whether this
removal should fully remove connectivity through the load balancer
to the endpoint or should just disable directing further connections to
the endpoint. If the flag is 'false', then the load balancer assigns
a weight of 0 to the endpoint but does not remove it as a linux load
balancing destination. It does remove the endpoint as a docker load
balancing endpoint but tracks it in a special map of "disabled-but-not-
destroyed" load balancing endpoints. This allows traffic to continue
flowing, at least under Linux. If the flag is 'true', then the code
removes the endpoint entirely as a load balancing destination.
The sandbox.DisableService() method invokes deleteServiceInfoFromCluster()
with the flag sent to 'false', while the endpoint.sbLeave() method invokes
it with the flag set to 'true' to complete the removal on endpoint
finalization. Renaming the endpoint invokes deleteServiceInfoFromCluster()
with the flag set to 'true' because renaming attempts to completely
remove and then re-add each endpoint service entry.
The controller.rmServiceBinding() method, which carries out the operation,
similarly gets a new flag for whether to fully remove the endpoint. If
the flag is false, it does the job of moving the endpoint from the
load balancing set to the 'disabled' set. It then removes or
de-weights the entry in the OS load balancing table via
network.rmLBBackend(). It removes the service entirely via said method
ONLY IF there are no more live or disabled load balancing endpoints.
Similarly network.addLBBackend() requires slight tweaking to properly
manage the disabled set.
Finally, this change requires propagating the status of disabled
service endpoints via the networkDB. Accordingly, the patch includes
both code to generate and handle service update messages. It also
augments the service structure with a ServiceDisabled boolean to convey
whether an endpoint should ultimately be removed or just disabled.
This, naturally, required a rebuild of the protocol buffer code as well.
Signed-off-by: Chris Telfer <ctelfer@docker.com>
* Correct SetMatrix documentation
The SetMatrix is a generic data structure, so the description
should not be tight to any specific use
Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>
* Service Discovery reuse name and serviceBindings deletion
- Added logic to handle name reuse from different services
- Moved the deletion from the serviceBindings map at the end
of the rmServiceBindings body to avoid race with new services
Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>
* Avoid race on network cleanup
Use the locker to avoid the race between the network
deletion and new endpoints being created
Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>
* CleanupServiceBindings to clean the SD records
Allow the cleanupServicebindings to take care of the service discovery
cleanup. Also avoid to trigger the cleanup for each endpoint from an SD
point of view
LB and SD will be separated in the future
Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>
* Addressed comments
Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>
* NetworkDB deleteEntry has to happen
If there is an error locally guarantee that the delete entry
on network DB is still honored
Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>
changed the ipMap to SetMatrix to allow transient states
Compacted the addSvc and deleteSvc into a one single method
Updated the datastructure for backends to allow storing all the information needed
to cleanup properly during the cleanupServiceBindings
Removed the enable/disable Service logic that was racing with sbLeave/sbJoin logic
Add some debug logs to track further race conditions
Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>
When leaving the entire gossip cluster or when leaving a network
specific gossip cluster, we may not have had a chance to cleanup service
bindings by way of gossip updates due to premature closure of gossip
channel. Make sure to cleanup all service bindings since we are not
participating in the cluster any more.
Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
While trying to update loadbalancer state index the service both on id
and portconfig. From libnetwork point of view a service is not just
defined by its id but also the ports it exposes. When a service updates
its port its id remains the same but its portconfigs change which should
be treated as a new service in libnetwork in order to ensure proper
cleanup of old LB state and creation of new LB state.
Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
Ingress load balancer is achieved via a service sandbox which acts as
the proxy to translate incoming node port requests and mapping that to a
service entry. Once the right service is identified, the same internal
loadbalancer implementation is used to load balance to the right backend
instance.
Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
This PR adds support for loadbalancing across a group of endpoints that
share the same service configuration as passed in by
`OptionService`. The loadbalancer is implemented using ipvs with just
round robin scheduling supported for now.
Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
Add a notion of service in libnetwork so that a group of endpoints
which form a service can be treated as such so that service level
features can be added on top. Initially as part of this PR the support
to assign a name to the said service is added which results in DNS
queries to the service name to return all the IPs of the backing
endpoints so that DNS RR behavior on the service name can be achieved.
Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
