From 30fd526766b1695ef4e96bb7752d2cd9e4eaac76 Mon Sep 17 00:00:00 2001
From: Chris Bednarski <banzaimonkey@gmail.com>
Date: Fri, 25 Sep 2015 23:55:01 -0700
Subject: [PATCH] Use env.Get, remove sha256 checks, and change from regexp to
 strconv to test for int

---
 client/driver/docker.go | 32 +++++++-------------------------
 1 file changed, 7 insertions(+), 25 deletions(-)

diff --git a/client/driver/docker.go b/client/driver/docker.go
index 06f1bac96..1ae1f9b1d 100644
--- a/client/driver/docker.go
+++ b/client/driver/docker.go
@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"log"
-	"regexp"
 	"strconv"
 	"strings"
 
@@ -14,11 +13,6 @@ import (
 	"github.com/hashicorp/nomad/nomad/structs"
 )
 
-var (
-	reDockerSha = regexp.MustCompile("^[a-f0-9]{64}$")
-	reNumeric   = regexp.MustCompile("^[0-9]+$")
-)
-
 type DockerDriver struct {
 	DriverContext
 }
@@ -50,15 +44,14 @@ func (d *DockerDriver) Fingerprint(cfg *config.Config, node *structs.Node) (bool
 		return false, nil
 	}
 
-	node.Attributes["driver.docker"] = "true"
-
 	env, err := client.Version()
-	for _, item := range *env {
-		parts := strings.Split(item, "=")
-		if parts[0] == "Version" {
-			node.Attributes["driver.docker.version"] = parts[1]
-		}
+	if err != nil {
+		// We connected to the daemon but couldn't read the version so something
+		// is broken.
+		return false, err
 	}
+	node.Attributes["driver.docker"] = "true"
+	node.Attributes["driver.docker.version"] = env.Get("Version")
 
 	return true, nil
 }
@@ -132,7 +125,7 @@ func createContainer(ctx *ExecContext, task *structs.Task, logger *log.Logger) d
 			// Otherwise we'll setup a direct 1:1 mapping from the host port to
 			// the container, and assume that the process inside will read the
 			// environment variable and bind to the correct port.
-			if reNumeric.MatchString(label) {
+			if _, err := strconv.Atoi(label); err == nil {
 				dockerPorts[docker.Port(label+"/tcp")] = []docker.PortBinding{docker.PortBinding{HostIP: network.IP, HostPort: strconv.Itoa(port)}}
 				dockerPorts[docker.Port(label+"/udp")] = []docker.PortBinding{docker.PortBinding{HostIP: network.IP, HostPort: strconv.Itoa(port)}}
 				logger.Printf("[DEBUG] driver.docker: allocated port %s:%d -> %s (mapped)", network.IP, port, label)
@@ -221,12 +214,6 @@ func (d *DockerDriver) Start(ctx *ExecContext, task *structs.Task) (DriverHandle
 			return nil, fmt.Errorf("Failed to determine image id for `%s`: %s", image, err)
 		}
 	}
-
-	// Sanity check
-	if !reDockerSha.MatchString(dockerImage.ID) {
-		return nil, fmt.Errorf("Image id not in expected format (sha256); found %s", dockerImage.ID)
-	}
-
 	d.logger.Printf("[DEBUG] driver.docker: using image %s", dockerImage.ID)
 	d.logger.Printf("[INFO] driver.docker: identified image %s as %s", image, dockerImage.ID)
 
@@ -236,11 +223,6 @@ func (d *DockerDriver) Start(ctx *ExecContext, task *structs.Task) (DriverHandle
 		d.logger.Printf("[ERR] driver.docker: %s", err)
 		return nil, fmt.Errorf("Failed to create container from image %s", image)
 	}
-
-	// Sanity check
-	if !reDockerSha.MatchString(container.ID) {
-		return nil, fmt.Errorf("Container id not in expected format (sha256); found %s", container.ID)
-	}
 	d.logger.Printf("[INFO] driver.docker: created container %s", container.ID)
 
 	// Start the container