README
¶
Go App Engine for Managed VMs
This repository supports the Go runtime for Managed VMs on App Engine.
It provides APIs for interacting with App Engine services.
Its canonical import path is google.golang.org/appengine
.
See https://cloud.google.com/appengine/docs/go/managed-vms/ for more information.
Directory structure
The top level directory of this repository is the appengine
package. It
contains the
basic types (e.g. appengine.Context
) that are used across APIs. Specific API
packages are in subdirectories (e.g. datastore
).
There is an internal
subdirectory that contains service protocol buffers,
plus packages required for connectivity to make API calls. App Engine apps
should not directly import any package under internal
.
Updating a Go App Engine app
This section describes how to update a traditional Go App Engine app to run on Managed VMs.
1. Update YAML files
The app.yaml
file (and YAML files for modules) should have these new lines added:
vm: true
manual_scaling:
instances: 1
See https://cloud.google.com/appengine/docs/go/modules/#Go_Instance_scaling_and_class for details.
2. Update import paths
The import paths for App Engine packages are now fully qualified, based at google.golang.org/appengine
.
You will need to update your code to use import paths starting with that; for instance,
code importing appengine/datastore
will now need to import google.golang.org/appengine/datastore
.
You can do that manually, or by running this command to recursively update all Go source files in the current directory:
(may require GNU sed)
sed -i '/"appengine/{s,"appengine,"google.golang.org/appengine,;s,appengine_,appengine/,}' \
$(find . -name '*.go')
3. Update code using deprecated, removed or modified APIs
Most App Engine services are available with exactly the same API. A few APIs were cleaned up, and some are not available yet. This list summarises the differences:
appengine.Datacenter
now takes anappengine.Context
argument.datastore.PropertyLoadSaver
has been simplified to use slices in place of channels.search.FieldLoadSaver
now handles document metadata.taskqueue.QueueStats
no longer takes a maxTasks argument. That argument has been deprecated and unused for a long time.appengine/aetest
,appengine/blobstore
,appengine/cloudsql
andappengine/runtime
have not been ported yet.appengine.BackendHostname
andappengine.BackendInstance
were for the deprecated backends feature. Useappengine.ModuleHostname
andappengine.ModuleName
instead.appengine.IsCapabilityDisabled
andappengine/capability
are obsolete.- Most of
appengine/file
is deprecated. Use Google Cloud Storage instead. appengine/socket
is deprecated. Use the standardnet
package instead.
Documentation
¶
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 AccessToken(c Context, scopes ...string) (token string, expiry time.Time, err error)
- func AppID(c Context) string
- func Datacenter(c Context) string
- func DefaultVersionHostname(c Context) string
- func InstanceID() string
- func IsDevAppServer() bool
- func IsOverQuota(err error) bool
- func IsTimeoutError(err error) bool
- func ModuleHostname(c Context, module, version, instance string) (string, error)
- func ModuleName(c Context) string
- func RequestID(c Context) string
- func ServerSoftware() string
- func ServiceAccount(c Context) (string, error)
- func SignBytes(c Context, bytes []byte) (string, []byte, error)
- func VersionID(c Context) string
- type BlobKey
- type Certificate
- type Context
- type GeoPoint
- type MultiError
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
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 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 IsDevAppServer ¶
func IsDevAppServer() bool
IsDevAppServer reports whether the App Engine app is running in the development App Server.
func IsOverQuota ¶
IsOverQuota reports whether err represents an API call failure due to insufficient available quota.
func IsTimeoutError ¶
IsTimeoutError reports whether err is a timeout error.
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 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).
Types ¶
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) ([]Certificate, error)
PublicCertificates retrieves the public certificates for the app. They can be used to verify a signature returned by SignBytes.
type Context ¶
type Context interface { // Debugf formats its arguments according to the format, analogous to fmt.Printf, // and records the text as a log message at Debug level. Debugf(format string, args ...interface{}) // Infof is like Debugf, but at Info level. Infof(format string, args ...interface{}) // Warningf is like Debugf, but at Warning level. Warningf(format string, args ...interface{}) // Errorf is like Debugf, but at Error level. Errorf(format string, args ...interface{}) // Criticalf is like Debugf, but at Critical level. Criticalf(format string, args ...interface{}) // Internal use only. Call(service, method string, in, out proto.Message, opts *internal.CallOptions) error // Internal use only. Use AppID instead. FullyQualifiedAppID() string // Internal use only. Request() interface{} }
Context represents the context of an in-flight HTTP request.
func NewContext ¶
NewContext returns a context for an in-flight HTTP request. Repeated calls will return the same value.
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
Directories
¶
Path | Synopsis |
---|---|
Package channel implements the server side of App Engine's Channel API.
|
Package channel implements the server side of App Engine's Channel API. |
Package datastore provides a client for App Engine's datastore service.
|
Package datastore provides a client for App Engine's datastore service. |
Package delay provides a way to execute code outside the scope of a user request by using the taskqueue API.
|
Package delay provides a way to execute code outside the scope of a user request by using the taskqueue API. |
demos
|
|
Package file provides helper functions for using Google Cloud Storage.
|
Package file provides helper functions for using Google Cloud Storage. |
Package image provides image services.
|
Package image provides image services. |
Package internal provides support for package appengine.
|
Package internal provides support for package appengine. |
Package log provides the means of querying an application's logs from within an App Engine application.
|
Package log provides the means of querying an application's logs from within an App Engine application. |
Package mail provides the means of sending email from an App Engine application.
|
Package mail provides the means of sending email from an App Engine application. |
Package memcache provides a client for App Engine's distributed in-memory key-value store for small chunks of arbitrary data.
|
Package memcache provides a client for App Engine's distributed in-memory key-value store for small chunks of arbitrary data. |
Package module provides functions for interacting with modules.
|
Package module provides functions for interacting with modules. |
Package remote_api implements the /_ah/remote_api endpoint.
|
Package remote_api implements the /_ah/remote_api endpoint. |
Package search provides a client for App Engine's search service.
|
Package search provides a client for App Engine's search service. |
Package taskqueue provides a client for App Engine's taskqueue service.
|
Package taskqueue provides a client for App Engine's taskqueue service. |
Package urlfetch provides an http.RoundTripper implementation for fetching URLs via App Engine's urlfetch service.
|
Package urlfetch provides an http.RoundTripper implementation for fetching URLs via App Engine's urlfetch service. |
Package user provides a client for App Engine's user authentication service.
|
Package user provides a client for App Engine's user authentication service. |
Package xmpp provides the means to send and receive instant messages to and from users of XMPP-compatible services.
|
Package xmpp provides the means to send and receive instant messages to and from users of XMPP-compatible services. |