Documentation ¶
Overview ¶
Package utils defines utilities for the agent.
Index ¶
- Constants
- func ExponentialBackoffDuration(retryCount uint) time.Duration
- func ListPendingRequests(client *http.Client, proxyHost, backendID string, ...) ([]string, error)
- func ReadRequest(client *http.Client, proxyHost, backendID, requestID string, ...) error
- func RoundTripperWithVMIdentity(ctx context.Context, wrapped http.RoundTripper, proxyURL string, ...) http.RoundTripper
- func ShutdownSignalChan() <-chan struct{}
- type ForwardedRequest
- type PendingRequests
- type RequestCallback
- type ResponseForwarder
Constants ¶
const ( // PendingPath is the URL subpath for pending requests held by the proxy. PendingPath = "agent/pending" // RequestPath is the URL subpath for reading a specific request held by the proxy. RequestPath = "agent/request" // ResponsePath is the URL subpath for posting a request response to the proxy. ResponsePath = "agent/response" // HeaderUserID is the name of a response header used by the proxy to identify the end user. HeaderUserID = "X-Inverting-Proxy-User-ID" // HeaderBackendID is the name of a request header used to uniquely identify this agent. HeaderBackendID = "X-Inverting-Proxy-Backend-ID" // HeaderVMID is the name of a request header used to report the VM // (if any) on which the agent is running. HeaderVMID = "X-Inverting-Proxy-VM-ID" // HeaderRequestID is the name of a request/response header used to uniquely // identify a proxied request. HeaderRequestID = "X-Inverting-Proxy-Request-ID" // HeaderRequestStartTime is the name of a response header used by the proxy // to report the start time of a proxied request. HeaderRequestStartTime = "X-Inverting-Proxy-Request-Start-Time" // JitterPercent sets the jitter for exponential backoff retry time JitterPercent = 0.1 )
Variables ¶
This section is empty.
Functions ¶
func ExponentialBackoffDuration ¶
ExponentialBackoffDuration gets time to wait before retry for exponential backoff
func ListPendingRequests ¶
func ListPendingRequests(client *http.Client, proxyHost, backendID string, metricHandler *metrics.MetricHandler) ([]string, error)
ListPendingRequests issues a single request to the proxy to ask for the IDs of pending requests.
func ReadRequest ¶
func ReadRequest(client *http.Client, proxyHost, backendID, requestID string, callback RequestCallback, metricHandler *metrics.MetricHandler) error
ReadRequest reads a forwarded client request from the inverting proxy.
If the returned request is non-nil, then it is passed to the provided callback.
func RoundTripperWithVMIdentity ¶
func RoundTripperWithVMIdentity(ctx context.Context, wrapped http.RoundTripper, proxyURL string, disableGCEVM bool) http.RoundTripper
RoundTripperWithVMIdentity returns an http.RoundTripper that includes a GCE VM ID token in every outbound request. The token is fetched from the metadata server and stored in the 'X-Inverting-Proxy-VM-ID' header.
This method relies on the Google Compute Engine functionality for verifying a VM's identity (https://cloud.google.com/compute/docs/instances/verifying-instance-identity), so it if this is not running inside of a Google Compute Engine VM, then it just returns the passed in RoundTripper.
func ShutdownSignalChan ¶
func ShutdownSignalChan() <-chan struct{}
Types ¶
type ForwardedRequest ¶
type ForwardedRequest struct { BackendID string RequestID string User string StartTime time.Time Contents *http.Request }
ForwardedRequest represents an end-client HTTP request that was forwarded to us by the inverting proxy.
type PendingRequests ¶
type PendingRequests []string
PendingRequests represents a list of request IDs that do not yet have a response.
type RequestCallback ¶
type RequestCallback func(client *http.Client, fr *ForwardedRequest) error
RequestCallback defines how the caller of `ReadRequest` uses the request that was read.
This is done as a callback so that the caller of `ReadRequest` does not have to remember to call `Close()` on the nested *http.Request object's body.
type ResponseForwarder ¶
type ResponseForwarder struct {
// contains filtered or unexported fields
}
ResponseForwarder implements http.ResponseWriter by dumping a wire-compatible representation of the response to 'proxyWriter' field.
ResponseForwarder is used by the agent to forward a response from the backend target to the inverting proxy.
func NewResponseForwarder ¶
func NewResponseForwarder(client *http.Client, proxyHost, backendID, requestID string, r *http.Request) (*ResponseForwarder, error)
NewResponseForwarder constructs a new ResponseForwarder that forwards to the given proxy for the specified request.
func (*ResponseForwarder) Close ¶
func (rf *ResponseForwarder) Close() error
Close signals that the response has been fully read from the backend server, waits for that response to be forwarded to the proxy, and then reports any errors that occured while forwarding the response.
func (*ResponseForwarder) Header ¶
func (rf *ResponseForwarder) Header() http.Header
Header implements the http.ResponseWriter interface.
func (*ResponseForwarder) Write ¶
func (rf *ResponseForwarder) Write(buf []byte) (int, error)
Write implements the http.ResponseWriter interface.
func (*ResponseForwarder) WriteHeader ¶
func (rf *ResponseForwarder) WriteHeader(code int)
WriteHeader implements the http.ResponseWriter interface.