Merge pull request #1073 from weaveworks/971_check_container_alive_in_api

make container aliveness check part of the ipam & dns API

common/docker/client.go

@@ -1,20 +1,10 @@
 package docker
 
 import (
-	"regexp"
-
 	"github.com/fsouza/go-dockerclient"
 	. "github.com/weaveworks/weave/common"
 )
 
-// Regexp that matches container IDs
-var containerIDregexp = regexp.MustCompile("^[a-f0-9]+$")
-
-// IsContainerID returns True if the string provided is a valid container id
-func IsContainerID(idStr string) bool {
-	return containerIDregexp.MatchString(idStr)
-}
-
 // An observer for container events
 type ContainerObserver interface {
 	ContainerDied(ident string) error
@@ -62,12 +52,6 @@ func (c *Client) AddObserver(ob ContainerObserver) error {
 
 // 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) {
-		Log.Debugf("[docker] '%s' does not seem to be a container id", idStr)
-		return false
-	}
-
-	// check with Docker whether the container is really running
 	container, err := c.InspectContainer(idStr)
 	if err == nil {
 		return !container.State.Running

ipam/http.go

@@ -78,7 +78,7 @@ func (alloc *Allocator) HandleHTTP(router *mux.Router, defaultSubnet address.CID
 			badRequest(w, fmt.Errorf("Unable to allocate: %s", err))
 			return
 		}
-		if dockerCli != nil && dockerCli.IsContainerNotRunning(ident) {
+		if r.FormValue("check-alive") == "true" && dockerCli != nil && dockerCli.IsContainerNotRunning(ident) {
 			common.Log.Infof("[allocator] '%s' is not running: freeing %s", ident, addr)
 			alloc.Free(ident, addr)
 			return
@@ -95,7 +95,7 @@ func (alloc *Allocator) HandleHTTP(router *mux.Router, defaultSubnet address.CID
 			badRequest(w, err)
 			return
 		}
-		if dockerCli != nil && dockerCli.IsContainerNotRunning(ident) {
+		if r.FormValue("check-alive") == "true" && dockerCli != nil && dockerCli.IsContainerNotRunning(ident) {
 			common.Log.Infof("[allocator] '%s' is not running: freeing %s", ident, newAddr)
 			alloc.Free(ident, newAddr)
 			return

nameserver/http.go

@@ -74,7 +74,7 @@ func ServeHTTP(listener net.Listener, version string, server *DNSServer, dockerC
 			} // oh, I already know this. whatever.
 		}
 
-		if dockerCli != nil && dockerCli.IsContainerNotRunning(idStr) {
+		if r.FormValue("check-alive") == "true" && dockerCli != nil && dockerCli.IsContainerNotRunning(idStr) {
 			Log.Infof("[http] '%s' is not running: removing", idStr)
 			server.Zone.DeleteRecords(idStr, name, ip)
 		}

weave

@@ -767,12 +767,17 @@ with_container_fqdn() {
 
 # Register FQDN in $2 as names for addresses $3.. under full container ID $1
 put_dns_fqdn() {
+    CHECK_ALIVE="-d check-alive=true"
+    if [ "$1" = "--no-check-alive" ] ; then
+        CHECK_ALIVE=
+        shift 1
+    fi
     CONTAINER_ID="$1"
     FQDN="$2"
     shift 2
 
     for ADDR in "$@" ; do
-        call_dns PUT /name/$CONTAINER_ID/${ADDR%/*} --data-urlencode fqdn=$FQDN || true
+        call_dns PUT /name/$CONTAINER_ID/${ADDR%/*} --data-urlencode fqdn=$FQDN $CHECK_ALIVE || true
     done
 }
 
@@ -827,13 +832,18 @@ ipam_claim() {
 # $1 is the full container id and following args are previously parsed CIDR_ARGS.
 # Returns ALL_CIDRS and IPAM_CIDRS
 ipam_cidrs() {
+    CHECK_ALIVE="?check-alive=true"
+    if [ "$1" = "--no-check-alive" ] ; then
+        CHECK_ALIVE=
+        shift 1
+    fi
     CONTAINER_ID="$1"
     shift 1
     ALL_CIDRS=""
     IPAM_CIDRs=""
     if [ $# -eq 0 ] ; then
         # If no addresses passed in, get one in the default subnet
-        IPAM_CIDRS=$(call_weave POST /ip/$CONTAINER_ID) || return 1
+        IPAM_CIDRS=$(call_weave POST /ip/$CONTAINER_ID$CHECK_ALIVE) || return 1
         if [ "$IPAM_CIDRS" = "404 page not found" ] ; then
             echo "No IP address supplied (use the -iprange option on 'weave launch' to enable IP address allocation)" >&2
             return 1
@@ -847,7 +857,7 @@ ipam_cidrs() {
             else
                 IPAM_URL=/ip/$CONTAINER_ID/"${1#net:}"
             fi
-            CIDR=$(call_weave POST $IPAM_URL) || return 1
+            CIDR=$(call_weave POST $IPAM_URL$CHECK_ALIVE) || return 1
             if [ "$CIDR" = "404 page not found" ] ; then
                 echo "IP address allocation must be enabled to use 'net:'" >&2
                 return 1
@@ -1353,7 +1363,7 @@ case "$COMMAND" in
     expose)
         collect_cidr_args "$@"
         shift $CIDR_ARG_COUNT
-        ipam_cidrs weave:expose $CIDR_ARGS
+        ipam_cidrs --no-check-alive weave:expose $CIDR_ARGS
         if [ $# -eq 0 ] ; then
             FQDN=""
         else
@@ -1368,7 +1378,7 @@ case "$COMMAND" in
                 add_iptables_rule nat WEAVE -d $CIDR ! -s $CIDR -j MASQUERADE
                 add_iptables_rule nat WEAVE -s $CIDR ! -d $CIDR -j MASQUERADE
                 if [ -n "$FQDN" ] ; then
-                    when_dns_running put_dns_fqdn weave:expose $FQDN $CIDR
+                    when_dns_running put_dns_fqdn --no-check-alive weave:expose $FQDN $CIDR
                 fi
             fi
         done
@@ -1377,7 +1387,7 @@ case "$COMMAND" in
     hide)
         collect_cidr_args "$@"
         shift $CIDR_ARG_COUNT
-        ipam_cidrs weave:expose $CIDR_ARGS
+        ipam_cidrs --no-check-alive weave:expose $CIDR_ARGS
         create_bridge --without-ethtool
         for CIDR in $ALL_CIDRS ; do
             if ip addr show dev $BRIDGE | grep -qF $CIDR ; then