Affinity labels like -e affinity:com.example.type==test

scheduler/filter/README.md

@@ -101,7 +101,7 @@ without specifying them when starting the node. Those tags are sourced from
 
 #### Containers
 
-You can schedule 2 containers and make the container #2 next to the container #1.
+You can schedule 2 containers and make the container #2 next to the container #1 using it's name or ID.
 
 ```bash
 $ docker run -d -p 80:80 --name front nginx
@@ -164,6 +164,33 @@ CONTAINER ID        IMAGE               COMMAND             CREATED
 
 As you can see here, the containers were only scheduled on nodes with the `redis` image already pulled.
 
+#### Labels
+
+You can schedule 2 containers and make the container #2 next to the container #1 using it's labels.
+
+```bash
+$ docker run -d -p 80:80 --label com.example.type=front nginx
+ 87c4376856a8
+
+$ docker ps
+CONTAINER ID        IMAGE               COMMAND             CREATED                  STATUS              PORTS                           NODE        NAMES
+87c4376856a8        nginx:latest        "nginx"             Less than a second ago   running             192.168.0.42:80->80/tcp         node-1      trusting_yonath
+```
+
+Using `-e affinity:com.example.type==front` will schedule a container next to the container with label `front`.
+
+```bash
+$ docker run -d -e affinity:com.example.type==front logger
+ 87c4376856a8
+
+$ docker ps
+CONTAINER ID        IMAGE               COMMAND             CREATED                  STATUS              PORTS                           NODE        NAMES
+87c4376856a8        nginx:latest        "nginx"             Less than a second ago   running             192.168.0.42:80->80/tcp         node-1      trusting_yonath
+963841b138d8        logger:latest       "logger"            Less than a second ago   running                                             node-1      happy_hawking
+```
+
+The `logger` container ends up on `node-1` because its affinity with the container `front`.
+
 #### Expression Syntax
 
 An affinity or a constraint expression consists of a `key` and a `value`.

scheduler/filter/affinity.go

@@ -51,6 +51,15 @@ func (f *AffinityFilter) Filter(config *dockerclient.ContainerConfig, nodes []*n
 				if affinity.Match(images...) {
 					candidates = append(candidates, node)
 				}
+			default:
+				labels := []string{}
+				for _, container := range node.Containers {
+					labels = append(labels, container.Labels[affinity.key])
+				}
+				if affinity.Match(labels...) {
+					candidates = append(candidates, node)
+				}
+
 			}
 		}
 		if len(candidates) == 0 {

scheduler/filter/expr.go

@@ -38,7 +38,7 @@ func parseExprs(key string, env []string) ([]expr, error) {
 
 					// validate key
 					// allow alpha-numeric
-					matched, err := regexp.MatchString(`^(?i)[a-z_][a-z0-9\-_]+$`, parts[0])
+					matched, err := regexp.MatchString(`^(?i)[a-z_][a-z0-9\-_.]+$`, parts[0])
 					if err != nil {
 						return nil, err
 					}

scheduler/filter/expr_test.go

@@ -15,14 +15,14 @@ func TestParseExprs(t *testing.T) {
 	_, err = parseExprs("constraint", []string{"constraint:node ==node1"})
 	assert.Error(t, err)
 
-	// Cannot use dot in key
-	_, err = parseExprs("constraint", []string{"constraint:no.de==node1"})
-	assert.Error(t, err)
-
 	// Cannot use * in key
 	_, err = parseExprs("constraint", []string{"constraint:no*de==node1"})
 	assert.Error(t, err)
 
+	// Allow dot in key
+	_, err = parseExprs("constraint", []string{"constraint:no.de==node1"})
+	assert.NoError(t, err)
+
 	// Allow leading underscore
 	_, err = parseExprs("constraint", []string{"constraint:_node==_node1"})
 	assert.NoError(t, err)

test/integration/affinities.bats

@@ -0,0 +1,56 @@
+#!/usr/bin/env bats
+
+load helpers
+
+function teardown() {
+	swarm_manage_cleanup
+	stop_docker
+}
+
+@test "container affinty" {
+	start_docker 2
+	swarm_manage
+
+	run docker_swarm run --name c1 -e constraint:node==node-0 -d busybox:latest sh
+	[ "$status" -eq 0 ]
+	run docker_swarm run --name c2 -e affinity:container==c1 -d busybox:latest sh
+	[ "$status" -eq 0 ]
+	run docker_swarm run --name c3 -e affinity:container!=c1 -d busybox:latest sh
+	[ "$status" -eq 0 ]
+
+	run docker_swarm inspect c1
+	[ "$status" -eq 0 ]
+	[[ "${output}" == *'"Name": "node-0"'* ]]
+
+	run docker_swarm inspect c2
+	[ "$status" -eq 0 ]
+	[[ "${output}" == *'"Name": "node-0"'* ]]
+
+	run docker_swarm inspect c3
+	[ "$status" -eq 0 ]
+	[[ "${output}" == *'"Name": "node-1"'* ]]
+}
+
+@test "label affinity" {
+	start_docker 2
+	swarm_manage
+
+	run docker_swarm run --name c1 --label test.label=true -e constraint:node==node-0 -d busybox:latest sh
+	[ "$status" -eq 0 ]
+	run docker_swarm run --name c2 -e affinity:test.label==true -d busybox:latest sh
+	[ "$status" -eq 0 ]
+	run docker_swarm run --name c3 -e affinity:test.label!=true -d busybox:latest sh
+	[ "$status" -eq 0 ]
+
+	run docker_swarm inspect c1
+	[ "$status" -eq 0 ]
+	[[ "${output}" == *'"Name": "node-0"'* ]]
+
+	run docker_swarm inspect c2
+	[ "$status" -eq 0 ]
+	[[ "${output}" == *'"Name": "node-0"'* ]]
+
+	run docker_swarm inspect c3
+	[ "$status" -eq 0 ]
+	[[ "${output}" == *'"Name": "node-1"'* ]]
+}

test/integration/helpers.bash

@@ -4,8 +4,8 @@
 SWARM_ROOT=${SWARM_ROOT:-${BATS_TEST_DIRNAME}/../..}
 
 # Docker image and version to use for integration tests.
-DOCKER_IMAGE=${DOCKER_IMAGE:-aluzzardi/docker}
-DOCKER_VERSION=${DOCKER_VERSION:-1.5}
+DOCKER_IMAGE=${DOCKER_IMAGE:-dockerswarm/docker}
+DOCKER_VERSION=${DOCKER_VERSION:-1.6}
 
 # Host on which the manager will listen to (random port between 6000 and 7000).
 SWARM_HOST=127.0.0.1:$(( ( RANDOM % 1000 )  + 6000 ))