The main purpose is to replace context.TODO with a context provided by the
caller. A secondary purpose is to enable contextual logging.
Modifying the existing interfaces and APIs would have a big impact on the
ecosystem. This is a no-go. Instead, the following approach was taken:
- All interfaces get duplicated in a *WithContext variant where the methods
also have a *WithContext suffix and the ctx parameter. All methods are
treated this way except for obvious local get methods (like RESTClient)
because it cannot be ruled out entirely that some implementation may
need a context.
- Implementations of these interfaces implement both method variants
which is possible because the method names are different.
The old methods are implemented as thin wrappers around the updated
code which is now the body of the new methods or shared helpers.
In some cases there is additional overhead (type checks, potentially
additional allocations) when using the old methods.
- To*WithContext helpers bridge from the old to the new interfaces. They
try a type cast first. Because the in-tree implementations implement
both, they can be used directly. For other implementations wrappers
are used.
- All old APIs and interfaces are marked as deprecated. There is no
intent to ever remove them, but consumers should be made aware
that there are now better alternatives. Implementations also
get marked this way even if nothing ever calls them directly
because it shows which code, at least theoretically, could get
removed.
- Existing unit tests do not get updated to the new APIs. This gives
us unit test coverage of the old and new API because the old
APIs call the new ones.
- In-tree consumers will be updated in follow-up PRs. This is likely
to be a longer process. Because of the deprecation comment,
`hack/golangci-lint.sh -n` can be used to find code which needs
to be updated.
Kubernetes-commit: 025b844bcabe0212c4dd56395ee18481602d7c65
This is a little more computationally expensive but reduces the
likelihood of a potentially malicious cache collision.
Signed-off-by: Nic Cope <nicc@rk0n.org>
Kubernetes-commit: c5957c284e1d23bdadc98fbbe2bb481fc1f345d4
This helps avoid (potentially malicious) collisions when reading and
writing cache data.
Signed-off-by: Nic Cope <nicc@rk0n.org>
Kubernetes-commit: 288a17fd337c65cb5aea44e44ecb74e9cb8088f5
Part of the API discovery cache uses an HTTP RoundTripper that
transparently caches responses to disk. The upstream implementation of
the disk cache is hard coded to call Sync() on every file it writes.
This has noticably poor performance on modern Macs, which ask their disk
controllers to flush all the way to persistant storage because Go uses
the `F_FULLFSYNC` fnctl. Apple recommends minimizing this behaviour in
order to avoid degrading performance and increasing disk wear.
The content of the discovery cache is not critical; it is indeed just a
cache and can be recreated by hitting the API servers' discovery
endpoints. This commit replaces upstream httpcache's diskcache
implementation with a similar implementation that can use CRC-32
checksums to detect corrupted cache entries at read-time. When such an
entry is detected (e.g. because it was only partially flushed to
permanent storage before the host lost power) the cache will report a
miss. This causes httpcache to fall back to its underlying HTTP
transport (i.e. the real API server) and re-cache the resulting value.
Apart from adding CRC-32 checksums and avoiding calling fsync this
implementation differs from upstream httpcache's diskcache package in
that it uses FNV-32a hashes rather than MD5 hashes of cache keys in
order to generate filenames.
Signed-off-by: Nic Cope <nicc@rk0n.org>
Kubernetes-commit: 7a2c6a432f9e8db8b84abe5607843429f8bff417
This benchmark is intended to demonstrate a performance improvement
gained by removing fsyncs. Refer to the below issue for more detail.
https://github.com/kubernetes/kubernetes/issues/110753
Signed-off-by: Nic Cope <nicc@rk0n.org>
Kubernetes-commit: eace46906512b99c23ad9635edc2ea055363a602
reflect latest struct changes
use correct discovery openapi test data layout
make the OpenAPIv3 interface less blue
field grouping
add copyrights
implement cached discovery client
add cached discovery tests
address review feedback
Kubernetes-commit: 075866b3e3ea029c243d82d8d6eb99e96d9c49d3
ServerResources function was deprecated and instead ServerGroupsAndResources
function is suggested.
This PR removes ServerResources function and move every place to use ServerGroupsAndResources.
Kubernetes-commit: ef39a8914291ba200bd5486c88a7575ffd4b7d1d
