From 13944f38114edee1d591ce8d883ccbd7e091b1be Mon Sep 17 00:00:00 2001
From: Bryan Boreham <bjboreham@gmail.com>
Date: Fri, 12 Jun 2015 16:49:15 +0100
Subject: [PATCH] Refactor is-running check so we can re-use more of the code

---
 common/docker/client.go | 25 +++++++++++++++----------
 nameserver/http.go      | 15 +++------------
 2 files changed, 18 insertions(+), 22 deletions(-)

diff --git a/common/docker/client.go b/common/docker/client.go
index 2c71fb42..bb96cf29 100644
--- a/common/docker/client.go
+++ b/common/docker/client.go
@@ -60,16 +60,21 @@ func (c *Client) AddObserver(ob ContainerObserver) error {
 	return nil
 }
 
-// IsContainerRunning returns true if the container is up and running
-func (c *Client) IsContainerRunning(idStr string) (bool, error) {
-	// check with Docker whether the container is really running
-	container, err := c.InspectContainer(idStr)
-	if err != nil {
-		if _, notThere := err.(*docker.NoSuchContainer); notThere {
-			return false, nil
-		}
-		return false, err
+// IsContainerNotRunning returns true if we have checked with Docker that the ID is not running
+func (c *Client) IsContainerNotRunning(idStr string) bool {
+	if !IsContainerID(idStr) {
+		Debug.Printf("[docker] '%s' does not seem to be a container id", idStr)
+		return false
 	}
 
-	return container.State.Running, nil
+	// check with Docker whether the container is really running
+	container, err := c.InspectContainer(idStr)
+	if err == nil {
+		return !container.State.Running
+	}
+	if _, notThere := err.(*docker.NoSuchContainer); notThere {
+		return true
+	}
+	Error.Printf("[docker] Could not check container status: %s", err)
+	return false
 }
diff --git a/nameserver/http.go b/nameserver/http.go
index 2361cd6a..a1501d98 100644
--- a/nameserver/http.go
+++ b/nameserver/http.go
@@ -75,18 +75,9 @@ func ServeHTTP(listener net.Listener, version string, server *DNSServer, dockerC
 			} // oh, I already know this. whatever.
 		}
 
-		if dockerCli != nil {
-			if !docker.IsContainerID(idStr) {
-				Debug.Printf("[http] '%s' does not seem to be a container id", idStr)
-				return
-			}
-
-			if running, err := dockerCli.IsContainerRunning(idStr); err != nil {
-				Error.Printf("[http] Could not check container status: %s", err)
-			} else if !running {
-				Info.Printf("[http] '%s' is not running: removing", idStr)
-				server.Zone.DeleteRecords(idStr, name, ip)
-			}
+		if dockerCli != nil && dockerCli.IsContainerNotRunning(idStr) {
+			Info.Printf("[http] '%s' is not running: removing", idStr)
+			server.Zone.DeleteRecords(idStr, name, ip)
 		}
 	})