README
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DOCUMENTATION DEPRECATION NOTICE: This file is deprecated. Please refer to the new migrated location. Please do not edit this file; instead, make changes to the new location!
The new location is served on the web at https://docs.prow.k8s.io/docs/ghproxy/ghcache/.
Documentation
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Overview ¶
Package ghcache implements an HTTP cache optimized for caching responses from the GitHub API (https://api.github.com).
Specifically, it enforces a cache policy that revalidates every cache hit with a conditional request to upstream regardless of cache entry freshness because conditional requests for unchanged resources don't cost any API tokens!!! See: https://developer.github.com/v3/#conditional-requests
It also provides request coalescing and prometheus instrumentation.
Index ¶
- Constants
- func CacheModeIsFree(mode CacheResponseMode) bool
- func NewDiskCache(roundTripper http.RoundTripper, cacheDir string, ...) http.RoundTripper
- func NewFromCache(roundTripper http.RoundTripper, cache CachePartitionCreator, ...) http.RoundTripper
- func NewMemCache(roundTripper http.RoundTripper, maxConcurrency int, ...) http.RoundTripper
- func NewRedisCache(roundTripper http.RoundTripper, redisAddress string, maxConcurrency int, ...) http.RoundTripper
- func Prune(baseDir string, now func() time.Time)
- type CachePartitionCreator
- type CacheResponseMode
- type RequestThrottlingTimes
Constants ¶
const LogMessageWithDiskPartitionFields = "Not using a partitioned cache because legacyDisablePartitioningByAuthHeader is true"
Variables ¶
This section is empty.
Functions ¶
func CacheModeIsFree ¶
func CacheModeIsFree(mode CacheResponseMode) bool
func NewDiskCache ¶
func NewDiskCache(roundTripper http.RoundTripper, cacheDir string, cacheSizeGB, maxConcurrency int, legacyDisablePartitioningByAuthHeader bool, cachePruneInterval time.Duration, throttlingTimes RequestThrottlingTimes) http.RoundTripper
NewDiskCache creates a GitHub cache RoundTripper that is backed by a disk cache. It supports a partitioned cache.
func NewFromCache ¶
func NewFromCache(roundTripper http.RoundTripper, cache CachePartitionCreator, maxConcurrency int, throttlingTimes RequestThrottlingTimes) http.RoundTripper
NewFromCache creates a GitHub cache RoundTripper that is backed by the specified httpcache.Cache implementation.
func NewMemCache ¶
func NewMemCache(roundTripper http.RoundTripper, maxConcurrency int, throttlingTimes RequestThrottlingTimes) http.RoundTripper
NewMemCache creates a GitHub cache RoundTripper that is backed by a memory cache. It supports a partitioned cache.
func NewRedisCache ¶
func NewRedisCache(roundTripper http.RoundTripper, redisAddress string, maxConcurrency int, throttlingTimes RequestThrottlingTimes) http.RoundTripper
NewRedisCache creates a GitHub cache RoundTripper that is backed by a Redis cache. Important note: The redis implementation does not support partitioning the cache which means that requests to the same path from different tokens will invalidate each other.
Types ¶
type CachePartitionCreator ¶
CachePartitionCreator creates a new cache partition using the given key
type CacheResponseMode ¶
type CacheResponseMode string
const ( CacheModeHeader = "X-Cache-Mode" ModeError CacheResponseMode = "ERROR" // internal error handling request ModeNoStore CacheResponseMode = "NO-STORE" // response not cacheable ModeMiss CacheResponseMode = "MISS" // not in cache, request proxied and response cached. ModeChanged CacheResponseMode = "CHANGED" // cache value invalid: resource changed, cache updated ModeSkip CacheResponseMode = "SKIP" // cache was skipped, not applicable. e.g. POST request. // The modes below are the happy cases in which the request is fulfilled for // free (no API tokens used). ModeCoalesced CacheResponseMode = "COALESCED" // coalesced request, this is a copied response ModeRevalidated CacheResponseMode = "REVALIDATED" // cached value revalidated and returned // TokenBudgetIdentifierHeader is used to identify the token budget for // which metrics should be recorded if set. If unset, the sha256sum of // the Authorization header will be used. TokenBudgetIdentifierHeader = "X-PROW-GHCACHE-TOKEN-BUDGET-IDENTIFIER" // TokenExpiryAtHeader includes a date at which the passed token expires and all associated caches // can be cleaned up. It's value must be in RFC3339 format. TokenExpiryAtHeader = "X-PROW-TOKEN-EXPIRES-AT" )
Cache response modes describe how ghcache fulfilled a request.
type RequestThrottlingTimes ¶
type RequestThrottlingTimes struct {
// contains filtered or unexported fields
}
RequestThrottlingTimes keeps the information about throttling times per API and request methods
func NewRequestThrottlingTimes ¶
func NewRequestThrottlingTimes(requestThrottlingTime, requestThrottlingTimeV4, requestThrottlingTimeForGET, requestThrottlingMaxDelayTime, requestThrottlingMaxDelayTimeV4 uint) RequestThrottlingTimes
NewRequestThrottlingTimes creates a new RequestThrottlingTimes and returns it
Source Files