Documentation
¶
Overview ¶
Package functions holds the starter handlers for scale-to-zero functions.
Index ¶
- Constants
- Variables
- func NewInvocationID() (string, error)
- func NewSecret() (string, error)
- func ParseEnvFile(data []byte) map[string]string
- func RedactHeaders(h http.Header) http.Header
- func Sign(secret string, timestamp int64, body []byte) string
- func Verify(secret, tsHeader, sigHeader string, body []byte, window time.Duration, ...) (string, error)
- type DevSpec
- type EnvVar
- type File
- type Input
- type InputStore
- type InvokeLimits
- type KVConfig
- type Limiter
- type Limits
- type Queue
- type QueueApps
- type QueueStore
- type Runtime
- type Starter
- type Target
- type TriggerConfig
Constants ¶
const ( EnvKVMaxKeyBytes = "APP_FUNCTION_KV_MAX_KEY_BYTES" EnvKVMaxValueBytes = "APP_FUNCTION_KV_MAX_VALUE_BYTES" EnvKVMaxKeys = "APP_FUNCTION_KV_MAX_KEYS" EnvKVMaxTotalBytes = "APP_FUNCTION_KV_MAX_TOTAL_BYTES" EnvKVMaxTTL = "APP_FUNCTION_KV_MAX_TTL_SECONDS" EnvKVURL = "APP_FUNCTION_KV_URL" // KVTokenEnv and KVURLEnv are the variables the function sees. KVTokenEnv = "KV_TOKEN" KVURLEnv = "KV_URL" // KVAPIPath is where functions reach the store, below the control plane's internal address. KVAPIPath = "/api/v1/function-kv" )
Environment variables that size the per-function key-value store.
const ( EnvRequestTimeout = "APP_FUNCTION_REQUEST_TIMEOUT" EnvRequestTimeoutMax = "APP_FUNCTION_REQUEST_TIMEOUT_MAX" EnvMaxConcurrency = "APP_FUNCTION_MAX_CONCURRENCY" EnvMaxConcurrencyCeiling = "APP_FUNCTION_MAX_CONCURRENCY_CEILING" )
Environment settings read by the control plane. A per-function value of 0 falls back to the Default* variable; the Max* variables bound what a function may ask for.
const ( HeaderInvocation = "X-Function-Invocation" HeaderAttempt = "X-Function-Attempt" HeaderSource = "X-Function-Source" )
Headers sent on every queued call so the handler can correlate and deduplicate it.
const ( HeaderTimestamp = "X-Signature-Timestamp" HeaderSignature = "X-Signature" )
Headers a webhook caller sends: a unix timestamp and sha256=hex(HMAC(secret, timestamp + "." + body)).
const DefaultPort = 8080
DefaultPort is the port every starter handler listens on unless PORT says otherwise.
const DevMountPath = "/app"
DevMountPath is where the handler directory is mounted in the dev container.
Variables ¶
var ( ErrSignatureMissing = errors.New("functions: signature headers missing") ErrSignatureStale = errors.New("functions: signature timestamp outside the replay window") ErrSignatureInvalid = errors.New("functions: signature does not match") )
Errors returned by Verify.
Functions ¶
func NewInvocationID ¶
NewInvocationID returns a random invocation id.
func ParseEnvFile ¶
ParseEnvFile reads KEY=VALUE lines, skipping blanks and # comments.
func RedactHeaders ¶
RedactHeaders returns a copy of h without credential headers.
Types ¶
type DevSpec ¶
DevSpec is how to run a handler directory in a throwaway container.
func DetectDevSpec ¶
DetectDevSpec picks the runtime of dir from its manifest file. image overrides the default image.
func (DevSpec) ShellCommand ¶
ShellCommand runs the handler from the mounted directory; the Engine API has no working-dir field on ContainerSpec.
type EnvVar ¶
type EnvVar struct {
Name string `json:"name"`
Required bool `json:"required"`
Description string `json:"description"`
}
EnvVar is one environment variable a starter reads.
type Input ¶
type Input struct {
Function string `json:"function"`
Method string `json:"method"`
Path string `json:"path"`
Headers http.Header `json:"headers"`
Body string `json:"body"`
At time.Time `json:"at"`
}
Input is the stored request of one invocation, kept only for opted-in functions.
type InputStore ¶
type InputStore struct {
// contains filtered or unexported fields
}
InputStore keeps recent inputs in memory, bounded by count, body size and age.
func NewInputStore ¶
func NewInputStore(lim InvokeLimits) *InputStore
NewInputStore builds a store honouring lim.
func (*InputStore) Forget ¶
func (s *InputStore) Forget(function string)
Forget drops every stored input of a function, used when capture is turned off.
func (*InputStore) Get ¶
func (s *InputStore) Get(id string) (Input, bool)
Get returns the stored input for id when it has not expired.
func (*InputStore) Put ¶
func (s *InputStore) Put(id string, in Input)
Put stores in under id and drops the oldest entries past the count cap. A body past the byte cap is cut.
type InvokeLimits ¶
type InvokeLimits struct {
InputEntries int
InputBodyBytes int
InputRetention time.Duration
RequestBytes int
ResponseBytes int
Timeout time.Duration
LogPad time.Duration
}
InvokeLimits are the size and time caps for test invocations and stored inputs.
func InvokeLimitsFromEnv ¶
func InvokeLimitsFromEnv(lookup func(string) (string, bool)) InvokeLimits
InvokeLimitsFromEnv reads the caps through lookup (os.LookupEnv when nil), falling back to defaults.
type KVConfig ¶
KVConfig is the server-wide key-value store sizing.
func KVConfigFromEnv ¶
KVConfigFromEnv reads KVConfig from the environment; getenv nil uses os.Getenv.
type Limiter ¶
type Limiter struct {
// contains filtered or unexported fields
}
Limiter counts requests held per function. The zero value is ready to use.
type Limits ¶
type Limits struct {
DefaultTimeout time.Duration
TimeoutCeiling time.Duration
DefaultConcurrency int
ConcurrencyCeiling int
}
Limits are the server-wide defaults and ceilings for per-function limits.
func LimitsFromEnv ¶
LimitsFromEnv reads Limits from the environment; getenv nil uses os.Getenv.
func (Limits) Concurrency ¶
func (l Limits) Concurrency(s store.FunctionSettings) int
Concurrency is the most requests held at once for s, or 0 for no limit.
type Queue ¶
type Queue struct {
Store QueueStore
Apps QueueApps
Target Target
Config TriggerConfig
Logger *slog.Logger
Client *http.Client
Now func() time.Time
// contains filtered or unexported fields
}
Queue delivers queued calls to sleeping functions with retries and a dead-letter state.
type QueueApps ¶
type QueueApps interface {
GetDesiredService(ctx context.Context, name string) (*store.DesiredService, error)
}
QueueApps resolves a function to its service.
type QueueStore ¶
type QueueStore interface {
ClaimFunctionInvocation(ctx context.Context, now time.Time) (store.FunctionInvocation, bool, error)
SettleFunctionInvocation(ctx context.Context, id, status string, next time.Time, code int, errMsg string, now time.Time) error
RequeueRunningFunctionInvocations(ctx context.Context, now time.Time) (int64, error)
PruneFunctionInvocations(ctx context.Context, cutoff time.Time) (int64, error)
}
QueueStore is the persistence the worker needs.
type Starter ¶
type Starter struct {
ID string `json:"id"`
Preset string `json:"preset"`
Name string `json:"name"`
Runtime string `json:"runtime"`
UsesKV bool `json:"uses_kv"`
Description string `json:"description"`
Env []EnvVar `json:"env"`
Files []File `json:"files"`
}
Starter is a complete, tested handler for one of the idea presets.
func LookupStarter ¶
LookupStarter returns the starter with the given id.
type TriggerConfig ¶
type TriggerConfig struct {
ReplayWindow time.Duration
MaxBodyBytes int64
MaxQueued int
MaxAttempts int
BackoffBase time.Duration
BackoffMax time.Duration
AttemptTimeout time.Duration
PollInterval time.Duration
Workers int
DoneRetention time.Duration
WebhookPerMinute int
}
TriggerConfig bounds the webhook trigger and the async queue. Every value is an env var.
func TriggerConfigFromEnv ¶
func TriggerConfigFromEnv(lookup func(string) (string, bool)) TriggerConfig
TriggerConfigFromEnv reads the APP_FUNCTION_* variables; unset or invalid values take the documented default.
Source Files