From 50e179c3af98f0ecd8219406cefeb1643d6af963 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Tue, 15 May 2018 08:44:58 -0700
Subject: [PATCH] command/intention/match

---
 command/commands_oss.go          |   2 +
 command/intention/match/match.go | 100 +++++++++++++++++++++++++++++++
 2 files changed, 102 insertions(+)
 create mode 100644 command/intention/match/match.go

diff --git a/command/commands_oss.go b/command/commands_oss.go
index 6452a4f6f..f166e82d7 100644
--- a/command/commands_oss.go
+++ b/command/commands_oss.go
@@ -17,6 +17,7 @@ import (
 	ixncreate "github.com/hashicorp/consul/command/intention/create"
 	ixndelete "github.com/hashicorp/consul/command/intention/delete"
 	ixnget "github.com/hashicorp/consul/command/intention/get"
+	ixnmatch "github.com/hashicorp/consul/command/intention/match"
 	"github.com/hashicorp/consul/command/join"
 	"github.com/hashicorp/consul/command/keygen"
 	"github.com/hashicorp/consul/command/keyring"
@@ -76,6 +77,7 @@ func init() {
 	Register("intention create", func(ui cli.Ui) (cli.Command, error) { return ixncreate.New(ui), nil })
 	Register("intention delete", func(ui cli.Ui) (cli.Command, error) { return ixndelete.New(ui), nil })
 	Register("intention get", func(ui cli.Ui) (cli.Command, error) { return ixnget.New(ui), nil })
+	Register("intention match", func(ui cli.Ui) (cli.Command, error) { return ixnmatch.New(ui), nil })
 	Register("join", func(ui cli.Ui) (cli.Command, error) { return join.New(ui), nil })
 	Register("keygen", func(ui cli.Ui) (cli.Command, error) { return keygen.New(ui), nil })
 	Register("keyring", func(ui cli.Ui) (cli.Command, error) { return keyring.New(ui), nil })
diff --git a/command/intention/match/match.go b/command/intention/match/match.go
new file mode 100644
index 000000000..651ff8fef
--- /dev/null
+++ b/command/intention/match/match.go
@@ -0,0 +1,100 @@
+package match
+
+import (
+	"flag"
+	"fmt"
+	"io"
+
+	"github.com/hashicorp/consul/api"
+	"github.com/hashicorp/consul/command/flags"
+	"github.com/mitchellh/cli"
+)
+
+func New(ui cli.Ui) *cmd {
+	c := &cmd{UI: ui}
+	c.init()
+	return c
+}
+
+type cmd struct {
+	UI    cli.Ui
+	flags *flag.FlagSet
+	http  *flags.HTTPFlags
+	help  string
+
+	// flags
+	flagSource      bool
+	flagDestination bool
+
+	// testStdin is the input for testing.
+	testStdin io.Reader
+}
+
+func (c *cmd) init() {
+	c.flags = flag.NewFlagSet("", flag.ContinueOnError)
+	c.flags.BoolVar(&c.flagSource, "source", false,
+		"Match intentions with the given source.")
+	c.flags.BoolVar(&c.flagDestination, "destination", false,
+		"Match intentions with the given destination.")
+
+	c.http = &flags.HTTPFlags{}
+	flags.Merge(c.flags, c.http.ClientFlags())
+	flags.Merge(c.flags, c.http.ServerFlags())
+	c.help = flags.Usage(help, c.flags)
+}
+
+func (c *cmd) Run(args []string) int {
+	if err := c.flags.Parse(args); err != nil {
+		return 2
+	}
+
+	args = c.flags.Args()
+	if len(args) != 1 {
+		c.UI.Error(fmt.Sprintf("Error: command requires exactly one argument: src or dst"))
+		return 2
+	}
+
+	// Create and test the HTTP client
+	client, err := c.http.APIClient()
+	if err != nil {
+		c.UI.Error(fmt.Sprintf("Error connecting to Consul agent: %s", err))
+		return 2
+	}
+
+	// Match the intention
+	matches, _, err := client.Connect().IntentionMatch(&api.IntentionMatch{
+		By:    api.IntentionMatchDestination,
+		Names: []string{args[0]},
+	}, nil)
+	if err != nil {
+		c.UI.Error(fmt.Sprintf("Error matching the connection: %s", err))
+		return 2
+	}
+
+	for _, ixn := range matches[args[0]] {
+		c.UI.Output(ixn.String())
+	}
+
+	return 0
+}
+
+func (c *cmd) Synopsis() string {
+	return synopsis
+}
+
+func (c *cmd) Help() string {
+	return c.help
+}
+
+const synopsis = "Show intentions that match a source or destination."
+const help = `
+Usage: consul intention match [options] SRC|DST
+
+  Show the list of intentions that would be enforced for a given source
+  or destination. The intentions are listed in the order they would be
+  evaluated.
+
+      $ consul intention match db
+      $ consul intention match -source web
+
+`