From 64f591875db7fead5c88e0b4d0df24338232d069 Mon Sep 17 00:00:00 2001
From: Chris Baker <cgbaker@hashicorp.com>
Date: Tue, 8 Jan 2019 00:09:21 +0000
Subject: [PATCH] moved interp key regex out to a helper function

---
 command/agent/command.go      | 19 +++++++++----------
 command/agent/config_parse.go |  4 +---
 helper/funcs.go               | 13 +++++++++++++
 3 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/command/agent/command.go b/command/agent/command.go
index fdab3e91d..5740f8e91 100644
--- a/command/agent/command.go
+++ b/command/agent/command.go
@@ -9,24 +9,25 @@ import (
 	"os/signal"
 	"path/filepath"
 	"reflect"
-	"regexp"
 	"sort"
 	"strconv"
 	"strings"
 	"syscall"
 	"time"
 
-	metrics "github.com/armon/go-metrics"
+	"github.com/hashicorp/nomad/helper"
+
+	"github.com/armon/go-metrics"
 	"github.com/armon/go-metrics/circonus"
 	"github.com/armon/go-metrics/datadog"
 	"github.com/armon/go-metrics/prometheus"
 	"github.com/hashicorp/consul/lib"
-	checkpoint "github.com/hashicorp/go-checkpoint"
-	discover "github.com/hashicorp/go-discover"
-	gsyslog "github.com/hashicorp/go-syslog"
+	"github.com/hashicorp/go-checkpoint"
+	"github.com/hashicorp/go-discover"
+	"github.com/hashicorp/go-syslog"
 	"github.com/hashicorp/logutils"
-	flaghelper "github.com/hashicorp/nomad/helper/flag-helpers"
-	gatedwriter "github.com/hashicorp/nomad/helper/gated-writer"
+	"github.com/hashicorp/nomad/helper/flag-helpers"
+	"github.com/hashicorp/nomad/helper/gated-writer"
 	"github.com/hashicorp/nomad/nomad/structs/config"
 	"github.com/hashicorp/nomad/version"
 	"github.com/mitchellh/cli"
@@ -187,8 +188,6 @@ func (c *Command) readConfig() *Config {
 	// Parse the meta flags.
 	metaLength := len(meta)
 	if metaLength != 0 {
-		validKeyRe, _ := regexp.Compile(`^[^.]+(\.[^.]+)*$`)
-
 		cmdConfig.Client.Meta = make(map[string]string, metaLength)
 		for _, kv := range meta {
 			parts := strings.SplitN(kv, "=", 2)
@@ -197,7 +196,7 @@ func (c *Command) readConfig() *Config {
 				return nil
 			}
 
-			if !validKeyRe.MatchString(parts[0]) {
+			if !helper.IsValidInterpVariable(parts[0]) {
 				c.Ui.Error(fmt.Sprintf("Invalid Client.Meta key: %v", parts[0]))
 				return nil
 			}
diff --git a/command/agent/config_parse.go b/command/agent/config_parse.go
index 6e681b54b..ed8e09dbb 100644
--- a/command/agent/config_parse.go
+++ b/command/agent/config_parse.go
@@ -6,7 +6,6 @@ import (
 	"io"
 	"os"
 	"path/filepath"
-	"regexp"
 	"time"
 
 	multierror "github.com/hashicorp/go-multierror"
@@ -439,9 +438,8 @@ func parseClient(result **ClientConfig, list *ast.ObjectList) error {
 			}
 		}
 
-		validKeyRe, _ := regexp.Compile(`^[^.]+(\.[^.]+)*$`)
 		for k := range config.Meta {
-			if !validKeyRe.MatchString(k) {
+			if !helper.IsValidInterpVariable(k) {
 				return fmt.Errorf("invalid Client.Meta key: %v", k)
 			}
 		}
diff --git a/helper/funcs.go b/helper/funcs.go
index cf9cc3dae..1daa8c8ff 100644
--- a/helper/funcs.go
+++ b/helper/funcs.go
@@ -15,6 +15,11 @@ import (
 // validUUID is used to check if a given string looks like a UUID
 var validUUID = regexp.MustCompile(`(?i)^[\da-f]{8}-[\da-f]{4}-[\da-f]{4}-[\da-f]{4}-[\da-f]{12}$`)
 
+// validInterpVarKey matches valid dotted variable names for interpolation. The
+// string must begin with one or more non-dot characters which may be followed
+// by sequences containing a dot followed by a one or more non-dot characters.
+var validInterpVarKey = regexp.MustCompile(`^[^.]+(\.[^.]+)*$`)
+
 // IsUUID returns true if the given string is a valid UUID.
 func IsUUID(str string) bool {
 	const uuidLen = 36
@@ -25,6 +30,14 @@ func IsUUID(str string) bool {
 	return validUUID.MatchString(str)
 }
 
+// IsValidInterpVariable returns true if a valid dotted variable names for
+// interpolation. The string must begin with one or more non-dot characters
+// which may be followed by sequences containing a dot followed by a one or more
+// non-dot characters.
+func IsValidInterpVariable(str string) bool {
+	return validInterpVarKey.MatchString(str)
+}
+
 // HashUUID takes an input UUID and returns a hashed version of the UUID to
 // ensure it is well distributed.
 func HashUUID(input string) (output string, hashed bool) {