s3 cache client-side support

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

vendor/github.com/aws/aws-sdk-go-v2/credentials/endpointcreds/provider.go

@@ -0,0 +1,133 @@
+// Package endpointcreds provides support for retrieving credentials from an
+// arbitrary HTTP endpoint.
+//
+// The credentials endpoint Provider can receive both static and refreshable
+// credentials that will expire. Credentials are static when an "Expiration"
+// value is not provided in the endpoint's response.
+//
+// Static credentials will never expire once they have been retrieved. The format
+// of the static credentials response:
+//    {
+//        "AccessKeyId" : "MUA...",
+//        "SecretAccessKey" : "/7PC5om....",
+//    }
+//
+// Refreshable credentials will expire within the "ExpiryWindow" of the Expiration
+// value in the response. The format of the refreshable credentials response:
+//    {
+//        "AccessKeyId" : "MUA...",
+//        "SecretAccessKey" : "/7PC5om....",
+//        "Token" : "AQoDY....=",
+//        "Expiration" : "2016-02-25T06:03:31Z"
+//    }
+//
+// Errors should be returned in the following format and only returned with 400
+// or 500 HTTP status codes.
+//    {
+//        "code": "ErrorCode",
+//        "message": "Helpful error message."
+//    }
+package endpointcreds
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+
+	"github.com/aws/aws-sdk-go-v2/aws"
+	"github.com/aws/aws-sdk-go-v2/credentials/endpointcreds/internal/client"
+	"github.com/aws/smithy-go/middleware"
+)
+
+// ProviderName is the name of the credentials provider.
+const ProviderName = `CredentialsEndpointProvider`
+
+type getCredentialsAPIClient interface {
+	GetCredentials(context.Context, *client.GetCredentialsInput, ...func(*client.Options)) (*client.GetCredentialsOutput, error)
+}
+
+// Provider satisfies the aws.CredentialsProvider interface, and is a client to
+// retrieve credentials from an arbitrary endpoint.
+type Provider struct {
+	// The AWS Client to make HTTP requests to the endpoint with. The endpoint
+	// the request will be made to is provided by the aws.Config's
+	// EndpointResolver.
+	client getCredentialsAPIClient
+
+	options Options
+}
+
+// HTTPClient is a client for sending HTTP requests
+type HTTPClient interface {
+	Do(*http.Request) (*http.Response, error)
+}
+
+// Options is structure of configurable options for Provider
+type Options struct {
+	// Endpoint to retrieve credentials from. Required
+	Endpoint string
+
+	// HTTPClient to handle sending HTTP requests to the target endpoint.
+	HTTPClient HTTPClient
+
+	// Set of options to modify how the credentials operation is invoked.
+	APIOptions []func(*middleware.Stack) error
+
+	// The Retryer to be used for determining whether a failed requested should be retried
+	Retryer aws.Retryer
+
+	// Optional authorization token value if set will be used as the value of
+	// the Authorization header of the endpoint credential request.
+	AuthorizationToken string
+}
+
+// New returns a credentials Provider for retrieving AWS credentials
+// from arbitrary endpoint.
+func New(endpoint string, optFns ...func(*Options)) *Provider {
+	o := Options{
+		Endpoint: endpoint,
+	}
+
+	for _, fn := range optFns {
+		fn(&o)
+	}
+
+	p := &Provider{
+		client: client.New(client.Options{
+			HTTPClient: o.HTTPClient,
+			Endpoint:   o.Endpoint,
+			APIOptions: o.APIOptions,
+			Retryer:    o.Retryer,
+		}),
+		options: o,
+	}
+
+	return p
+}
+
+// Retrieve will attempt to request the credentials from the endpoint the Provider
+// was configured for. And error will be returned if the retrieval fails.
+func (p *Provider) Retrieve(ctx context.Context) (aws.Credentials, error) {
+	resp, err := p.getCredentials(ctx)
+	if err != nil {
+		return aws.Credentials{}, fmt.Errorf("failed to load credentials, %w", err)
+	}
+
+	creds := aws.Credentials{
+		AccessKeyID:     resp.AccessKeyID,
+		SecretAccessKey: resp.SecretAccessKey,
+		SessionToken:    resp.Token,
+		Source:          ProviderName,
+	}
+
+	if resp.Expiration != nil {
+		creds.CanExpire = true
+		creds.Expires = *resp.Expiration
+	}
+
+	return creds, nil
+}
+
+func (p *Provider) getCredentials(ctx context.Context) (*client.GetCredentialsOutput, error) {
+	return p.client.GetCredentials(ctx, &client.GetCredentialsInput{AuthorizationToken: p.options.AuthorizationToken})
+}