sorted/mysql: automatically find IPs of hosts named *.cloudsql.google.internal

Change-Id: Ib03add64c2c6b4de7fc6059f2a9c22065e2b2e7d

pkg/sorted/mysql/cloudsql.go

@@ -0,0 +1,66 @@
+/*
+Copyright 2014 The Camlistore Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package mysql
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"log"
+	"strings"
+
+	sqladmin "camlistore.org/third_party/code.google.com/p/google-api-go-client/sqladmin/v1beta3"
+	"camlistore.org/third_party/github.com/bradfitz/gce"
+)
+
+const cloudSQLSuffix = ".cloudsql.google.internal"
+
+func maybeRemapCloudSQL(host string) (out string, err error) {
+	if !strings.HasSuffix(host, cloudSQLSuffix) {
+		return host, nil
+	}
+	inst := strings.TrimSuffix(host, cloudSQLSuffix)
+	if !gce.OnGCE() {
+		return "", errors.New("CloudSQL support only available when running on Google Compute Engine.")
+	}
+	proj, err := gce.ProjectID()
+	if err != nil {
+		return "", fmt.Errorf("Failed to lookup GCE project ID: %v", err)
+	}
+
+	admin, _ := sqladmin.New(gce.Client)
+	listRes, err := admin.Instances.List(proj).Do()
+	if err != nil {
+		return "", fmt.Errorf("error enumerating Cloud SQL instances: %v", err)
+	}
+	for _, it := range listRes.Items {
+		if !strings.EqualFold(it.Instance, inst) {
+			continue
+		}
+		js, _ := json.Marshal(it)
+		log.Printf("Found Cloud SQL instance %s: %s", inst, js)
+		for _, ipm := range it.IpAddresses {
+			return ipm.IpAddress, nil
+		}
+		return "", fmt.Errorf("No external IP address for Cloud SQL instances %s", inst)
+	}
+	var found []string
+	for _, it := range listRes.Items {
+		found = append(found, it.Instance)
+	}
+	return "", fmt.Errorf("Cloud SQL instance %q not found. Found: %q", inst, found)
+}