Support AWS, implement dry-run and quiet modes

README.md

@@ -1,17 +1,103 @@
 # cloud-floating-ip
 
-NOT YET READY.
+Implement a floating IP by modifying GCP or AWS routes.
 
-Implement a floating IP by modifying GCE or AWS routes.
+## Usage
 
-## Build
+All ec2/gce instances that may carry the floating IP (become "primary")
+should be allowed to route traffic: SourceDestCheck (EC2) or canIpForward
+(GCE) must be enabled.
 
-Assuming you have go 1.9 and glide in the path, and GOPATH configured:
+Those instances should accept the traffic to the floating IP. The IP may
+be assigned to a loopback or a dummy interface on all instances:
 
-```shell
-make deps
-make build
+```bash
+ip link add dummy0 type dummy
+ip address add 10.200.0.50/32 dev dummy0
 ```
 
-## Usage
+To route the floating IP to the current instance (which becomes "primary"):
+```bash
+# see what would be changed
+cloud-floating-ip -i 10.200.0.50 --dry-run preempt
+
+# apply the change
+cloud-floating-ip -i 10.200.0.50 preempt
+```
+
+The IP can be preempted, using the same `preempt` command, by other
+instances in the VPC.
+
+To verify the status ("primary" or "standby") of any instance:
+```bash
+cloud-floating-ip -i 10.200.0.50 status
+```
+
+To store the configuration (avoid those repetitive `-i ...` arguments):
+```bash
+cat<<EOF > /etc/cloud-floating-ip.yaml
+ip: 10.200.0.50
+quiet: true
+EOF
+```
+
+## Options
+
+The --ip argument is mandatory. Other settings can be collected from
+instance's metadata (and instance profile or service account) when
+running from an AWS or GCE instance.
+
+
+```
+Usage:
+  cloud-floating-ip [flags]
+  cloud-floating-ip [command]
+
+Available Commands:
+  destroy     Delete the routes managed by cloud-floating-ip
+  help        Help about any command
+  preempt     Preempt an IP address and route it to the instance
+  status      Display the status of the instance (owner or standby)
+
+Flags:
+  -c, --config string              config file (default is /etc/cloud-floating-ip.yaml)
+  -i, --ip string                  IP address
+  -d, --dry-run                    dry-run mode
+  -q, --quiet                      quiet mode
+  -h, --help                       help for cloud-floating-ip
+  -o, --hoster string              hosting provider (aws or gce)
+  -t, --instance string            instance name
+  -m, --ignore-main-table          (AWS) ignore routes in main table
+  -a, --aws-access-key-id string   (AWS) access key Id
+  -k, --aws-secret-key string      (AWS) secret key
+  -p, --project string             (GCP) project id
+  -r, --region string              (AWS) region name
+  -z, --zone string                (GCP) zone name
+```
+
+## Required privileges
+
+On EC2, the account running `cloud-floating-ip` must have the following rights:
+```
+ec2:DescribeInstances
+ec2:CreateRoute
+ec2:DescribeRouteTables
+ec2:ReplaceRoute
+ec2:DeleteRoute
+```
+
+On GCE:
+```
+compute.routes.get
+compute.routes.create
+compute.routes.delete
+compute.instances.get
+container.operations.get
+container.operations.list
+```
+
+## Limitations
+
+* `cloud-floating-ip` does not support instances with multiple interfaces in the VPC yet.
+* On GCE, `cloud-floating-ip` won't remove already created, pre-existing routes with a custom name
 

cmd/preempt.go

@@ -9,8 +9,8 @@ import (
 
 var preemptCmd = &cobra.Command{
 	Use:   "preempt",
-	Short: "Preempt an IP address and route it to an instanced",
-	Long:  `Preempt an IP address and route it to an instance`,
+	Short: "Preempt an IP address and route it to the instance",
+	Long:  `Preempt an IP address and route it to the instance`,
 	Run: func(cmd *cobra.Command, args []string) {
 		run.Run(newCfiConfig(), operation.CfiPreempt)
 	},

cmd/root.go

@@ -22,7 +22,9 @@ var (
 	dryrun   bool
 	quiet    bool
 	project  string
+	region   string
 	zone     string
+	nomain   bool
 	accessk  string
 	secretk  string
 )
@@ -35,7 +37,9 @@ func newCfiConfig() *config.CfiConfig {
 		DryRun:        viper.GetBool("dry-run"),
 		Quiet:         viper.GetBool("quiet"),
 		Project:       viper.GetString("project"),
+		Region:        viper.GetString("region"),
 		Zone:          viper.GetString("zone"),
+		NoMain:        viper.GetBool("ignore-main-table"),
 		AwsAccesKeyID: viper.GetString("aws-access-key-id"),
 		AwsSecretKey:  viper.GetString("aws-secret-key"),
 	}
@@ -56,8 +60,8 @@ var rootCmd = &cobra.Command{
 	Use:   "cloud-floating-ip",
 	Short: "Implement a floating IP by modifying GCE or AWS routes.",
 	Long: `Implement a floating IP by modifying GCE or AWS routes.
-Most of the arguments (except the floating IP address) can be guessed from
-instance's metadata (when running from an AWS or GCE instance).
+The --ip argument is mandatory. Other settings can be guessed from
+instance's metadata when running from an AWS or GCE instance.
 	`,
 	Run: func(cmd *cobra.Command, args []string) {
 		run.Run(newCfiConfig(), operation.CfiStatus)
@@ -100,17 +104,23 @@ func init() {
 	rootCmd.PersistentFlags().BoolVarP(&quiet, "quiet", "q", false, "quiet mode")
 	bindPFlag("quiet", "quiet")
 
-	rootCmd.PersistentFlags().StringVarP(&project, "project", "p", "", "GCP project id")
+	rootCmd.PersistentFlags().StringVarP(&project, "project", "p", "", "(GCP) project id")
 	bindPFlag("project", "project")
 
-	rootCmd.PersistentFlags().StringVarP(&zone, "zone", "z", "", "zone name")
+	rootCmd.PersistentFlags().StringVarP(&region, "region", "r", "", "(AWS) region name")
+	bindPFlag("region", "region")
+
+	rootCmd.PersistentFlags().StringVarP(&zone, "zone", "z", "", "(GCP) zone name")
 	bindPFlag("zone", "zone")
 
-	rootCmd.PersistentFlags().StringVarP(&accessk, "aws-access-key-id", "a", "", "AWS access key Id")
-	bindPFlag("accessk", "accessk")
+	rootCmd.PersistentFlags().BoolVarP(&nomain, "ignore-main-table", "m", false, "(AWS) ignore routes in main table")
+	bindPFlag("ignore-main-table", "ignore-main-table")
+
+	rootCmd.PersistentFlags().StringVarP(&accessk, "aws-access-key-id", "a", "", "(AWS) access key Id")
+	bindPFlag("aws-access-key-id", "aws-access-key-id")
 
-	rootCmd.PersistentFlags().StringVarP(&secretk, "aws-secret-key", "k", "", "AWS secret key")
-	bindPFlag("secretk", "secretk")
+	rootCmd.PersistentFlags().StringVarP(&secretk, "aws-secret-key", "k", "", "(AWS) secret key")
+	bindPFlag("aws-secret-key", "aws-secret-key")
 }
 
 // initConfig reads in config file and ENV variables if set.

config/config.go

@@ -23,6 +23,12 @@ type CfiConfig struct {
 	// Zone is the AWS or GCP zone of the target instance
 	Zone string
 
+	// Region is the AWS region
+	Region string
+
+	// Ignore tables associated with the main route table
+	NoMain bool
+
 	// AwsAccesKeyID (AWS only) is the acccess key to use (if we don't use an instance profile's role)
 	AwsAccesKeyID string
 

glide.yaml

@@ -17,3 +17,5 @@ import:
 - package: google.golang.org/api
   subpackages:
   - compute/v0.beta
+- package: github.com/aws/aws-sdk-go
+  version: ^1.13.11