agent: Validate datacenter is valid. Fixes #169.

command/agent/command.go

@@ -11,6 +11,7 @@ import (
 	"net"
 	"os"
 	"os/signal"
+	"regexp"
 	"runtime"
 	"strings"
 	"syscall"
@@ -20,6 +21,9 @@ import (
 // gracefulTimeout controls how long we wait before forcefully terminating
 var gracefulTimeout = 5 * time.Second
 
+// validDatacenter is used to validate a datacenter
+var validDatacenter = regexp.MustCompile("^[a-zA-Z0-9_-]+$")
+
 // Command is a Command implementation that runs a Consul agent.
 // The command will not end unless a shutdown message is sent on the
 // ShutdownCh. If two messages are sent on the ShutdownCh it will forcibly
@@ -111,6 +115,12 @@ func (c *Command) readConfig() *Config {
 		return nil
 	}
 
+	// Verify data center is valid
+	if !validDatacenter.MatchString(config.Datacenter) {
+		c.Ui.Error("Datacenter must be alpha-numeric with underscores and hypens only")
+		return nil
+	}
+
 	// Only allow bootstrap mode when acting as a server
 	if config.Bootstrap && !config.Server {
 		c.Ui.Error("Bootstrap mode cannot be enabled when server mode is not enabled")

command/agent/command_test.go

@@ -8,3 +8,26 @@ import (
 func TestCommand_implements(t *testing.T) {
 	var _ cli.Command = new(Command)
 }
+
+func TestValidDatacenter(t *testing.T) {
+	shouldMatch := []string{
+		"dc1",
+		"east-aws-001",
+		"PROD_aws01-small",
+	}
+	noMatch := []string{
+		"east.aws",
+		"east!aws",
+		"first,second",
+	}
+	for _, m := range shouldMatch {
+		if !validDatacenter.MatchString(m) {
+			t.Fatalf("expected match: %s", m)
+		}
+	}
+	for _, m := range noMatch {
+		if validDatacenter.MatchString(m) {
+			t.Fatalf("expected no match: %s", m)
+		}
+	}
+}