19862: Fix RandomUUID length.

[arvados.git] / sdk / go / arvados / client.go

diff --git a/sdk/go/arvados/client.go b/sdk/go/arvados/client.go
index 24d5ac3e335c824f5ea4a444c6066ce37f3cc86f..5a498b01f0c98716ae0c34466272bf43ea7bf812 100644 (file)
--- a/sdk/go/arvados/client.go
+++ b/sdk/go/arvados/client.go
@@ -7,6 +7,7 @@ package arvados
 import (
        "bytes"
        "context"
+       "crypto/rand"
        "crypto/tls"
        "encoding/json"
        "errors"
@@ -15,6 +16,8 @@ import (
        "io/fs"
        "io/ioutil"
        "log"
+       "math/big"
+       "net"
        "net/http"
        "net/url"
        "os"
@@ -94,7 +97,40 @@ func NewClientFromConfig(cluster *Cluster) (*Client, error) {
        if ctrlURL.Host == "" {
                return nil, fmt.Errorf("no host in config Services.Controller.ExternalURL: %v", ctrlURL)
        }
+       var hc *http.Client
+       if srvaddr := os.Getenv("ARVADOS_SERVER_ADDRESS"); srvaddr != "" {
+               // When this client is used to make a request to
+               // https://{ctrlhost}:port/ (any port), it dials the
+               // indicated port on ARVADOS_SERVER_ADDRESS instead.
+               //
+               // This is invoked by arvados-server boot to ensure
+               // that server->server traffic (e.g.,
+               // keepproxy->controller) only hits local interfaces,
+               // even if the Controller.ExternalURL host is a load
+               // balancer / gateway and not a local interface
+               // address (e.g., when running on a cloud VM).
+               //
+               // This avoids unnecessary delay/cost of routing
+               // external traffic, and also allows controller to
+               // recognize other services as internal clients based
+               // on the connection source address.
+               divertedHost := (*url.URL)(&cluster.Services.Controller.ExternalURL).Hostname()
+               var dialer net.Dialer
+               hc = &http.Client{
+                       Transport: &http.Transport{
+                               TLSClientConfig: &tls.Config{InsecureSkipVerify: cluster.TLS.Insecure},
+                               DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
+                                       host, port, err := net.SplitHostPort(addr)
+                                       if err == nil && network == "tcp" && host == divertedHost {
+                                               addr = net.JoinHostPort(srvaddr, port)
+                                       }
+                                       return dialer.DialContext(ctx, network, addr)
+                               },
+                       },
+               }
+       }
        return &Client{
+               Client:   hc,
                Scheme:   ctrlURL.Scheme,
                APIHost:  ctrlURL.Host,
                Insecure: cluster.TLS.Insecure,
@@ -117,10 +153,10 @@ func NewClientFromConfig(cluster *Cluster) (*Client, error) {
 // Space characters are trimmed when reading the settings file, so
 // these are equivalent:
 //
-//   ARVADOS_API_HOST=localhost\n
-//   ARVADOS_API_HOST=localhost\r\n
-//   ARVADOS_API_HOST = localhost \n
-//   \tARVADOS_API_HOST = localhost\n
+//     ARVADOS_API_HOST=localhost\n
+//     ARVADOS_API_HOST=localhost\r\n
+//     ARVADOS_API_HOST = localhost \n
+//     \tARVADOS_API_HOST = localhost\n
 func NewClientFromEnv() *Client {
        vars := map[string]string{}
        home := os.Getenv("HOME")
@@ -294,11 +330,11 @@ func (c *Client) DoAndDecode(dst interface{}, req *http.Request) error {
 
 // Convert an arbitrary struct to url.Values. For example,
 //
-//     Foo{Bar: []int{1,2,3}, Baz: "waz"}
+//     Foo{Bar: []int{1,2,3}, Baz: "waz"}
 //
 // becomes
 //
-//     url.Values{`bar`:`{"a":[1,2,3]}`,`Baz`:`waz`}
+//     url.Values{`bar`:`{"a":[1,2,3]}`,`Baz`:`waz`}
 //
 // params itself is returned if it is already an url.Values.
 func anythingToValues(params interface{}) (url.Values, error) {
@@ -565,3 +601,17 @@ func (c *Client) PathForUUID(method, uuid string) (string, error) {
        }
        return path, nil
 }
+
+var maxUUIDInt = (&big.Int{}).Exp(big.NewInt(36), big.NewInt(15), nil)
+
+func RandomUUID(clusterID, infix string) string {
+       n, err := rand.Int(rand.Reader, maxUUIDInt)
+       if err != nil {
+               panic(err)
+       }
+       nstr := n.Text(36)
+       for len(nstr) < 15 {
+               nstr = "0" + nstr
+       }
+       return clusterID + "-" + infix + "-" + nstr
+}