Merge pull request #141 from moul/wrapper

Add wrapper (#122)

README.md

@@ -16,6 +16,7 @@
 3. [Configuration](#configuration)
 4. [Usage](#usage)
 5. [Install](#install)
+  * [Register the wrapper (optional)](#register-the-wrapper-optional)
 6. [Getting started](#getting-started)
 7. [Changelog](#changelog)
 8. [Alternative version](#alternative-version)
@@ -303,6 +304,27 @@ brew install assh --HEAD
 
 Get a released version on: https://github.com/moul/advanced-ssh-config/releases
 
+---
+
+#### Register the wrapper (optional)
+
+To improve experience when using advanced pattern matching, add the following at the end of your .bashrc or .zshrc:
+
+```bash
+alias ssh="assh wrapper ssh"
+```
+
+This step is not *mandatory* but highly *recommended*.
+
+---
+
+**Note**: `ssh` does not understand advanced patterns;
+To bypass this limitation, `assh` maintains a list of *known hosts* and regenerate the `~/.ssh/config` with all those expanded *known hosts*.
+
+Without the wrapper, the `~/.ssh/config` risks to be outdated when connecting to a new host for the first time and you will need to launch the command again.
+
+With the wrapper, `ssh` will *always* be called with an updated `~/.ssh/config` file.
+
 ## Getting started
 
 1. Backup your old `~/.ssh/config`: `cp ~/.ssh/config ~/.ssh/config.backup`
@@ -314,6 +336,7 @@ Get a released version on: https://github.com/moul/advanced-ssh-config/releases
 
 ### master (unreleased)
 
+* Add wrapper and `known_hosts` support to handle *advanced patterns* ([#122](https://github.com/moul/advanced-ssh-config/issues/122))
 * Add build information in .ssh/config header ([#49](https://github.com/moul/advanced-ssh-config/issues/49))
 * Add Autocomplete support ([#48](https://github.com/moul/advanced-ssh-config/issues/48))
 * Initial `Aliases` support ([#133](https://github.com/moul/advanced-ssh-config/issues/133))

contrib/homebrew/assh.rb

@@ -22,6 +22,14 @@ def install
     zsh_completion.install "contrib/completion/zsh_autocomplete"
   end
 
+  def caveats
+    <<-EOS.undent
+    To activate advanced pattern matching, add the following at the end of your .bashrc or .zshrc:
+
+      alias ssh="assh wrapper ssh"
+    EOS
+  end
+
   test do
     output = shell_output(bin/"assh --version")
     assert output.include? "assh version 2"

pkg/commands/commands.go

@@ -66,4 +66,16 @@ var Commands = []cli.Command{
 		Usage:  "Display system-wide information",
 		Action: cmdInfo,
 	},
+	{
+		Name:  "wrapper",
+		Usage: "Initialize assh, then run ssh/scp/rsync...",
+		Subcommands: []cli.Command{
+			{
+				Name:   "ssh",
+				Action: cmdWrapper,
+				Usage:  "Wrap ssh",
+				Flags:  config.SSHFlags,
+			},
+		},
+	},
 }

pkg/commands/proxy.go

@@ -43,22 +43,36 @@ func cmdProxy(c *cli.Context) {
 		Logger.Fatalf("Cannot open configuration file: %v", err)
 	}
 
+	if err = conf.LoadKnownHosts(); err != nil {
+		Logger.Debugf("Failed to load assh known_hosts: %v", err)
+	}
+
+	target := c.Args()[0]
+
+	isOutdated, err := conf.IsConfigOutdated(target)
+	if err != nil {
+		Logger.Warnf("Cannot check if ~/.ssh/config is outdated.")
+	}
+	if isOutdated {
+		Logger.Debugf("The configuration file is outdated, rebuilding it before calling ssh")
+		Logger.Warnf("'~/.ssh/config' has been rewritten.  SSH needs to be restarted.  See https://github.com/moul/advanced-ssh-config/issues/122 for more information.")
+		Logger.Debugf("Saving SSH config")
+		err = conf.SaveSshConfig()
+		if err != nil {
+			Logger.Fatalf("Cannot save SSH config file: %v", err)
+		}
+	}
+
 	// FIXME: handle complete host with json
 
-	host, err := computeHost(c.Args()[0], c.Int("port"), conf)
+	host, err := computeHost(target, c.Int("port"), conf)
 	if err != nil {
-		Logger.Fatalf("Cannot get host '%s': %v", c.Args()[0], err)
+		Logger.Fatalf("Cannot get host '%s': %v", target, err)
 	}
 	w := Logger.Writer()
 	defer w.Close()
 	host.WriteSshConfigTo(w)
 
-	Logger.Debugf("Saving SSH config")
-	err = conf.SaveSshConfig()
-	if err != nil {
-		Logger.Fatalf("Cannot save SSH config file: %v", err)
-	}
-
 	Logger.Debugf("Proxying")
 	err = proxy(host, conf, dryRun)
 	if err != nil {
@@ -138,8 +152,8 @@ func proxyDirect(host *config.Host, dryRun bool) error {
 
 func proxyCommand(host *config.Host, command string, dryRun bool) error {
 	command = host.ExpandString(command)
-	args, err := shlex.Split(command)
 	Logger.Debugf("ProxyCommand: %s", command)
+	args, err := shlex.Split(command)
 	if err != nil {
 		return err
 	}

pkg/commands/proxy_test.go

@@ -1,6 +1,7 @@
 package commands
 
 import (
+	"fmt"
 	"strings"
 	"testing"
 
@@ -21,6 +22,8 @@ hosts:
     User: toor
   "*.ddd":
     HostName: 1.3.5.7
+  eee:
+    ResolveCommand: /bin/sh -c "echo 42.42.42.42"
 defaults:
   Port: 22
   User: root
@@ -55,3 +58,50 @@ func TestComputeHost(t *testing.T) {
 		So(host.Port, ShouldEqual, "42")
 	})
 }
+
+func Test_proxyCommand(t *testing.T) {
+	Convey("Testing proxyCommand()", t, func() {
+		// FIXME: test stdout
+		config := config.New()
+		err := config.LoadConfig(strings.NewReader(configExample))
+		host, err := computeHost("aaa", 0, config)
+		So(err, ShouldBeNil)
+
+		err = proxyCommand(host, "echo test from proxyCommand", false)
+		So(err, ShouldBeNil)
+
+		err = proxyCommand(host, "/bin/sh -c 'echo test from proxyCommand'", false)
+		So(err, ShouldBeNil)
+
+		err = proxyCommand(host, "/bin/sh -c 'exit 1'", false)
+		So(err, ShouldNotBeNil)
+
+		err = proxyCommand(host, "blah", true)
+		So(err, ShouldResemble, fmt.Errorf("dry-run: Execute [blah]"))
+	})
+}
+
+func Test_hostPrepare(t *testing.T) {
+	Convey("Testing hostPrepare()", t, func() {
+		config := config.New()
+		err := config.LoadConfig(strings.NewReader(configExample))
+
+		host, err := computeHost("aaa", 0, config)
+		So(err, ShouldBeNil)
+		So(host.HostName, ShouldEqual, "1.2.3.4")
+		So(hostPrepare(host), ShouldBeNil)
+		So(host.HostName, ShouldEqual, "1.2.3.4")
+
+		host, err = computeHost("bbb", 0, config)
+		So(err, ShouldBeNil)
+		So(host.HostName, ShouldEqual, "bbb")
+		So(hostPrepare(host), ShouldBeNil)
+		So(host.HostName, ShouldEqual, "bbb")
+
+		host, err = computeHost("eee", 0, config)
+		So(err, ShouldBeNil)
+		So(host.HostName, ShouldEqual, "eee")
+		So(hostPrepare(host), ShouldBeNil)
+		So(host.HostName, ShouldEqual, "42.42.42.42")
+	})
+}

pkg/commands/wrapper.go

@@ -0,0 +1,70 @@
+package commands
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"syscall"
+
+	"github.com/codegangsta/cli"
+
+	"github.com/moul/advanced-ssh-config/pkg/config"
+	. "github.com/moul/advanced-ssh-config/pkg/logger"
+)
+
+func cmdWrapper(c *cli.Context) {
+	if len(c.Args()) < 1 {
+		Logger.Fatalf("Missing <target> argument. See usage with 'assh wrapper %s -h'.", c.Command.Name)
+	}
+
+	// prepare variables
+	target := c.Args()[0]
+	command := c.Args()[1:]
+	options := []string{}
+	for _, flag := range config.SSHBoolFlags {
+		if c.Bool(flag) {
+			options = append(options, fmt.Sprintf("-%s", flag))
+		}
+	}
+	for _, flag := range config.SSHStringFlags {
+		if val := c.String(flag); val != "" {
+			options = append(options, fmt.Sprintf("-%s", flag))
+			options = append(options, val)
+		}
+	}
+	args := []string{c.Command.Name}
+	args = append(args, options...)
+	args = append(args, target)
+	args = append(args, command...)
+	bin, err := exec.LookPath(c.Command.Name)
+	if err != nil {
+		Logger.Fatalf("Cannot find %q in $PATH", c.Command.Name)
+	}
+
+	Logger.Debugf("Wrapper called with bin=%v target=%v command=%v options=%v, args=%v", bin, target, command, options, args)
+
+	// check if config is up-to-date
+	conf, err := config.Open()
+	if err != nil {
+		Logger.Fatalf("Cannot open configuration file: %v", err)
+	}
+
+	if err = conf.LoadKnownHosts(); err != nil {
+		Logger.Debugf("Failed to load assh known_hosts: %v", err)
+	}
+
+	// check if .ssh/config is outdated
+	isOutdated, err := conf.IsConfigOutdated(target)
+	if err != nil {
+		Logger.Error(err)
+	}
+	if isOutdated {
+		Logger.Debugf("The configuration file is outdated, rebuilding it before calling %s", c.Command.Name)
+		if err = conf.SaveSshConfig(); err != nil {
+			Logger.Error(err)
+		}
+	}
+
+	// Execute Binary
+	syscall.Exec(bin, args, os.Environ())
+}