Documentation
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Overview ¶
Package appengine provides basic functionality for Google App Engine.
For more information on how to write Go apps for Google App Engine, see: https://cloud.google.com/appengine/docs/go/
Index ¶
- func APICall(ctx context.Context, service, method string, in, out proto.Message) error
- func AccessToken(c context.Context, scopes ...string) (token string, expiry time.Time, err error)
- func AppID(c context.Context) string
- func BackgroundContext() context.Context
- func Datacenter(c context.Context) string
- func DefaultVersionHostname(c context.Context) string
- func InstanceID() string
- func IsAppEngine() bool
- func IsDevAppServer() bool
- func IsFlex() bool
- func IsOverQuota(err error) bool
- func IsSecondGen() bool
- func IsStandard() bool
- func IsTimeoutError(err error) bool
- func Main()
- func ModuleHostname(c context.Context, module, version, instance string) (string, error)
- func ModuleName(c context.Context) string
- func Namespace(c context.Context, namespace string) (context.Context, error)
- func NewContext(req *http.Request) context.Context
- func RequestID(c context.Context) string
- func ServerSoftware() string
- func ServiceAccount(c context.Context) (string, error)
- func SignBytes(c context.Context, bytes []byte) (keyName string, signature []byte, err error)
- func VersionID(c context.Context) string
- func WithAPICallFunc(ctx context.Context, f APICallFunc) context.Context
- func WithContext(parent context.Context, req *http.Request) context.Context
- type APICallFunc
- type BlobKey
- type Certificate
- type GeoPoint
- type MultiError
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func APICall ¶
APICall performs an API call.
This is not intended for general use; it is exported for use in conjunction with WithAPICallFunc.
func AccessToken ¶
AccessToken generates an OAuth2 access token for the specified scopes on behalf of service account of this application. This token will expire after the returned time.
func AppID ¶
AppID returns the application ID for the current application. The string will be a plain application ID (e.g. "appid"), with a domain prefix for custom domain deployments (e.g. "example.com:appid").
func BackgroundContext ¶
BackgroundContext returns a context not associated with a request. This should only be used when not servicing a request. This only works in App Engine "flexible environment".
func Datacenter ¶
Datacenter returns an identifier for the datacenter that the instance is running in.
func DefaultVersionHostname ¶
DefaultVersionHostname returns the standard hostname of the default version of the current application (e.g. "my-app.appspot.com"). This is suitable for use in constructing URLs.
func InstanceID ¶
func InstanceID() string
InstanceID returns a mostly-unique identifier for this instance.
func IsAppEngine ¶
func IsAppEngine() bool
IsAppEngine reports whether the App Engine app is running on App Engine, in either the standard or flexible environment.
func IsDevAppServer ¶
func IsDevAppServer() bool
IsDevAppServer reports whether the App Engine app is running in the development App Server.
func IsFlex ¶
func IsFlex() bool
IsFlex reports whether the App Engine app is running in the flexible environment.
func IsOverQuota ¶
IsOverQuota reports whether err represents an API call failure due to insufficient available quota.
func IsSecondGen ¶
func IsSecondGen() bool
IsSecondGen reports whether the App Engine app is running on the second generation runtimes (>= Go 1.11).
func IsStandard ¶
func IsStandard() bool
IsStandard reports whether the App Engine app is running in the standard environment. This includes both the first generation runtimes (<= Go 1.9) and the second generation runtimes (>= Go 1.11).
func IsTimeoutError ¶
IsTimeoutError reports whether err is a timeout error.
func Main ¶
func Main()
Main is the principal entry point for an app running in App Engine.
On App Engine Flexible it installs a trivial health checker if one isn't already registered, and starts listening on port 8080 (overridden by the $PORT environment variable).
See https://cloud.google.com/appengine/docs/flexible/custom-runtimes#health_check_requests for details on how to do your own health checking.
On App Engine Standard it ensures the server has started and is prepared to receive requests.
Main never returns.
Main is designed so that the app's main package looks like this:
package main
import (
"google.golang.org/appengine"
_ "myapp/package0"
_ "myapp/package1"
)
func main() {
appengine.Main()
}
The "myapp/packageX" packages are expected to register HTTP handlers in their init functions.
func ModuleHostname ¶
ModuleHostname returns a hostname of a module instance. If module is the empty string, it refers to the module of the current instance. If version is empty, it refers to the version of the current instance if valid, or the default version of the module of the current instance. If instance is empty, ModuleHostname returns the load-balancing hostname.
func ModuleName ¶
ModuleName returns the module name of the current instance.
func Namespace ¶
Namespace returns a replacement context that operates within the given namespace.
func NewContext ¶
NewContext returns a context for an in-flight HTTP request. This function is cheap.
func RequestID ¶
RequestID returns a string that uniquely identifies the request.
func ServerSoftware ¶
func ServerSoftware() string
ServerSoftware returns the App Engine release version. In production, it looks like "Google App Engine/X.Y.Z". In the development appserver, it looks like "Development/X.Y".
func ServiceAccount ¶
ServiceAccount returns a string representing the service account name, in the form of an email address (typically app_id@appspot.gserviceaccount.com).
func SignBytes ¶
SignBytes signs bytes using a private key unique to your application.
func VersionID ¶
VersionID returns the version ID for the current application. It will be of the form "X.Y", where X is specified in app.yaml, and Y is a number generated when each version of the app is uploaded. It does not include a module name.
Types ¶
type APICallFunc ¶
APICallFunc defines a function type for handling an API call. See WithCallOverride.
type BlobKey ¶
type BlobKey string
BlobKey is a key for a blobstore blob.
Conceptually, this type belongs in the blobstore package, but it lives in the appengine package to avoid a circular dependency: blobstore depends on datastore, and datastore needs to refer to the BlobKey type.
type Certificate ¶
Certificate represents a public certificate for the app.
func PublicCertificates ¶
func PublicCertificates(c context.Context) ([]Certificate, error)
PublicCertificates retrieves the public certificates for the app. They can be used to verify a signature returned by SignBytes.
type GeoPoint ¶
type GeoPoint struct {
Lat, Lng float64
}
GeoPoint represents a location as latitude/longitude in degrees.
type MultiError ¶
type MultiError []error
MultiError is returned by batch operations when there are errors with particular elements. Errors will be in a one-to-one correspondence with the input elements; successful elements will have a nil entry.
func (MultiError) Error ¶
func (m MultiError) Error() string
Source Files
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Directories
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| Path | Synopsis |
|---|---|
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Package internal provides support for package appengine.
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Package internal provides support for package appengine. |
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Package urlfetch provides an http.RoundTripper implementation for fetching URLs via App Engine's urlfetch service.
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Package urlfetch provides an http.RoundTripper implementation for fetching URLs via App Engine's urlfetch service. |