Documentation
¶
Overview ¶
Package runtimeconfigurator provides a runtimevar driver implementation to read configurations from Cloud Runtime Configurator service and ability to detect changes and get updates.
User constructs a Client that provides the gRPC connection, then use the client to construct any number of runtimevar.Variable objects using NewConfig method.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var Set = wire.NewSet( Dial, NewClient, )
Set is a Wire provider set that provides *Client using a default connection to the Runtime Configurator API given a GCP token source.
Functions ¶
func Dial ¶
func Dial(ctx context.Context, ts gcp.TokenSource) (pb.RuntimeConfigManagerClient, func(), error)
Dial opens a gRPC connection to the Runtime Configurator API.
The second return value is a function that can be called to clean up the connection opened by Dial.
Types ¶
type Client ¶
type Client struct {
// contains filtered or unexported fields
}
A Client constructs runtime variables using the Runtime Configurator API.
func NewClient ¶
func NewClient(stub pb.RuntimeConfigManagerClient) *Client
NewClient returns a new client that makes calls to the given gRPC stub.
Example ¶
package main
import (
"context"
"log"
"github.com/Lioric/go-cloud/gcp"
"github.com/Lioric/go-cloud/runtimevar/runtimeconfigurator"
)
func main() {
ctx := context.Background()
creds, err := gcp.DefaultCredentials(ctx)
if err != nil {
log.Fatal(err)
}
stub, cleanup, err := runtimeconfigurator.Dial(ctx, creds.TokenSource)
if err != nil {
log.Fatal(err)
}
defer cleanup()
client := runtimeconfigurator.NewClient(stub)
// Now use the client.
_ = client
}
Output:
func (*Client) NewVariable ¶
func (c *Client) NewVariable(ctx context.Context, name ResourceName, decoder *runtimevar.Decoder, opts *WatchOptions) (*runtimevar.Variable, error)
NewVariable constructs a runtimevar.Variable object with this package as the driver implementation. Provide a decoder to unmarshal updated configurations into similar objects during the Watch call. If WaitTime is not set the poller will check for updates to the variable every 30 seconds.
Example ¶
package main
import (
"context"
"log"
"github.com/Lioric/go-cloud/runtimevar"
"github.com/Lioric/go-cloud/runtimevar/runtimeconfigurator"
)
func main() {
// Assume client was created at server startup.
ctx := context.Background()
client := openClient()
// MyAppConfig is an example unmarshaled type for configuration stored in key
// "projects/projectID/configs/configName/variables/appConfig". Runtime
// Configurator stores individual variables as strings or binary data, so a
// decoder automatically parses the data.
type MyAppConfig struct {
MsgOfTheDay string `json:"msg_of_the_day"`
}
decoder := runtimevar.NewDecoder(&MyAppConfig{}, runtimevar.JSONDecode)
// Fill these in with the values from the Cloud Console.
name := runtimeconfigurator.ResourceName{
ProjectID: "projectID",
Config: "configName",
Variable: "appConfig",
}
// Create a variable object to watch for changes.
v, err := client.NewVariable(ctx, name, decoder, nil)
if err != nil {
log.Fatal(err)
}
defer v.Close()
// Read the current value. Calling Watch() again will block until the value
// changes.
snapshot, err := v.Watch(ctx)
if err != nil {
log.Fatal(err)
}
// Value will always be of the decoder's type.
cfg := snapshot.Value.(*MyAppConfig)
log.Println(cfg.MsgOfTheDay)
}
func openClient() *runtimeconfigurator.Client {
return nil
}
Output:
type ResourceName ¶
ResourceName identifies the full configuration variable path used by the service.
func (ResourceName) String ¶
func (r ResourceName) String() string
String returns the full configuration variable path.
type WatchOptions ¶
type WatchOptions struct {
// WaitTime controls the frequency of RPC calls and checking for updates by the Watch method.
// A Watcher keeps track of the last time it made an RPC, when Watch is called, it waits for
// configured WaitTime from the last RPC before making another RPC. The smaller the value, the
// higher the frequency of making RPCs, which also means faster rate of hitting the API quota.
//
// If this option is not set or set to 0, it uses defaultWait value.
WaitTime time.Duration
}
WatchOptions provide optional configurations to the Watcher.
Source Files