From ac3a8b6ac9208bed348b33ca47c6629a7dd0866e Mon Sep 17 00:00:00 2001
From: Nishant Totla <nishanttotla@gmail.com>
Date: Wed, 10 Feb 2016 15:53:53 -0800
Subject: [PATCH 1/2] Adding functions to list filter constraints of all types

Signed-off-by: Nishant Totla <nishanttotla@gmail.com>
---
 scheduler/filter/affinity.go   | 13 +++++++++++++
 scheduler/filter/constraint.go | 13 +++++++++++++
 scheduler/filter/dependency.go | 10 ++++++++--
 scheduler/filter/filter.go     |  3 +++
 scheduler/filter/health.go     |  5 +++++
 scheduler/filter/port.go       | 18 ++++++++++++++++++
 6 files changed, 60 insertions(+), 2 deletions(-)

diff --git a/scheduler/filter/affinity.go b/scheduler/filter/affinity.go
index 6bc458d586..6727819e5a 100644
--- a/scheduler/filter/affinity.go
+++ b/scheduler/filter/affinity.go
@@ -76,3 +76,16 @@ func (f *AffinityFilter) Filter(config *cluster.ContainerConfig, nodes []*node.N
 
 	return nodes, nil
 }
+
+// Get a list of the affinities found in the container config.
+func (f *AffinityFilter) GetAllFilters(config *cluster.ContainerConfig) ([]string, error) {
+	allAffinities := []string{}
+	affinities, err := parseExprs(config.Affinities())
+	if err != nil {
+		return nil, err
+	}
+	for _, affinity := range affinities {
+		allAffinities = append(allAffinities, fmt.Sprintf("%s%s%s (soft=%t)", affinity.key, OPERATORS[affinity.operator], affinity.value, affinity.isSoft))
+	}
+	return allAffinities, nil
+}
diff --git a/scheduler/filter/constraint.go b/scheduler/filter/constraint.go
index 841d5feb3b..dcf454be93 100644
--- a/scheduler/filter/constraint.go
+++ b/scheduler/filter/constraint.go
@@ -51,3 +51,16 @@ func (f *ConstraintFilter) Filter(config *cluster.ContainerConfig, nodes []*node
 	}
 	return nodes, nil
 }
+
+// Get a list of the constraints found in the container config.
+func (f *ConstraintFilter) GetAllFilters(config *cluster.ContainerConfig) ([]string, error) {
+	allConstraints := []string{}
+	constraints, err := parseExprs(config.Constraints())
+	if err != nil {
+		return nil, err
+	}
+	for _, constraint := range constraints {
+		allConstraints = append(allConstraints, fmt.Sprintf("%s%s%s", constraint.key, OPERATORS[constraint.operator], constraint.value))
+	}
+	return allConstraints, nil
+}
diff --git a/scheduler/filter/dependency.go b/scheduler/filter/dependency.go
index 4a0ea9fdf0..0e8c078462 100644
--- a/scheduler/filter/dependency.go
+++ b/scheduler/filter/dependency.go
@@ -56,8 +56,8 @@ func (f *DependencyFilter) Filter(config *cluster.ContainerConfig, nodes []*node
 	return candidates, nil
 }
 
-// Get a string representation of the dependencies found in the container config.
-func (f *DependencyFilter) String(config *cluster.ContainerConfig) string {
+// Get a list of the dependencies found in the container config.
+func (f *DependencyFilter) GetAllFilters(config *cluster.ContainerConfig) ([]string, error) {
 	dependencies := []string{}
 	for _, volume := range config.HostConfig.VolumesFrom {
 		dependencies = append(dependencies, fmt.Sprintf("--volumes-from=%s", volume))
@@ -68,6 +68,12 @@ func (f *DependencyFilter) String(config *cluster.ContainerConfig) string {
 	if strings.HasPrefix(config.HostConfig.NetworkMode, "container:") {
 		dependencies = append(dependencies, fmt.Sprintf("--net=%s", config.HostConfig.NetworkMode))
 	}
+	return dependencies, nil
+}
+
+// Get a string representation of the dependencies found in the container config.
+func (f *DependencyFilter) String(config *cluster.ContainerConfig) string {
+	dependencies, _ := f.GetAllFilters(config)
 	return strings.Join(dependencies, " ")
 }
 
diff --git a/scheduler/filter/filter.go b/scheduler/filter/filter.go
index c17419acc4..b414c24f72 100644
--- a/scheduler/filter/filter.go
+++ b/scheduler/filter/filter.go
@@ -14,6 +14,9 @@ type Filter interface {
 
 	// Return a subset of nodes that were accepted by the filtering policy.
 	Filter(*cluster.ContainerConfig, []*node.Node, bool) ([]*node.Node, error)
+
+	// Return a list of constraints/filters provided
+	GetAllFilters(*cluster.ContainerConfig) ([]string, error)
 }
 
 var (
diff --git a/scheduler/filter/health.go b/scheduler/filter/health.go
index d6a27b54af..12f805c710 100644
--- a/scheduler/filter/health.go
+++ b/scheduler/filter/health.go
@@ -36,3 +36,8 @@ func (f *HealthFilter) Filter(_ *cluster.ContainerConfig, nodes []*node.Node, _
 
 	return result, nil
 }
+
+// Implements interface function, but currently redundant since we don't have node constraints
+func (f *HealthFilter) GetAllFilters(config *cluster.ContainerConfig) ([]string, error) {
+	return nil, nil
+}
diff --git a/scheduler/filter/port.go b/scheduler/filter/port.go
index 757a6c6b6a..2145ab44fd 100644
--- a/scheduler/filter/port.go
+++ b/scheduler/filter/port.go
@@ -119,6 +119,24 @@ func (p *PortFilter) compare(requested dockerclient.PortBinding, bindings map[st
 	return false
 }
 
+// Get a list of the port constraints found in the container config.
+func (p *PortFilter) GetAllFilters(config *cluster.ContainerConfig) ([]string, error) {
+	allPortConstraints := []string{}
+	if config.HostConfig.NetworkMode == "host" {
+		for port := range config.ExposedPorts {
+			allPortConstraints = append(allPortConstraints, fmt.Sprintf("port %s (Host mode)", port))
+		}
+		return allPortConstraints, nil
+	}
+
+	for _, port := range config.HostConfig.PortBindings {
+		for _, binding := range port {
+			allPortConstraints = append(allPortConstraints, fmt.Sprintf("port %s", binding.HostPort))
+		}
+	}
+	return allPortConstraints, nil
+}
+
 func bindsAllInterfaces(binding dockerclient.PortBinding) bool {
 	return binding.HostIp == "0.0.0.0" || binding.HostIp == ""
 }

From 5075e95612d41b0a467b4e23899180919ba8e7f1 Mon Sep 17 00:00:00 2001
From: Nishant Totla <nishanttotla@gmail.com>
Date: Wed, 10 Feb 2016 18:22:34 -0800
Subject: [PATCH 2/2] Printing entire set of unsatisfiable constraints for
 container scheduling

Signed-off-by: Nishant Totla <nishanttotla@gmail.com>
---
 scheduler/filter/affinity.go             |  4 ++--
 scheduler/filter/constraint.go           |  4 ++--
 scheduler/filter/dependency.go           |  6 +++---
 scheduler/filter/filter.go               | 24 ++++++++++++++++++++++--
 scheduler/filter/health.go               |  4 ++--
 scheduler/filter/port.go                 |  6 +++---
 test/integration/affinities.bats         |  3 ++-
 test/integration/build_with_filters.bats |  3 ++-
 test/integration/port-filters.bats       |  6 ++++--
 9 files changed, 42 insertions(+), 18 deletions(-)

diff --git a/scheduler/filter/affinity.go b/scheduler/filter/affinity.go
index 6727819e5a..d3903aff6a 100644
--- a/scheduler/filter/affinity.go
+++ b/scheduler/filter/affinity.go
@@ -77,8 +77,8 @@ func (f *AffinityFilter) Filter(config *cluster.ContainerConfig, nodes []*node.N
 	return nodes, nil
 }
 
-// Get a list of the affinities found in the container config.
-func (f *AffinityFilter) GetAllFilters(config *cluster.ContainerConfig) ([]string, error) {
+// GetFilters returns a list of the affinities found in the container config.
+func (f *AffinityFilter) GetFilters(config *cluster.ContainerConfig) ([]string, error) {
 	allAffinities := []string{}
 	affinities, err := parseExprs(config.Affinities())
 	if err != nil {
diff --git a/scheduler/filter/constraint.go b/scheduler/filter/constraint.go
index dcf454be93..91ab8b0c3d 100644
--- a/scheduler/filter/constraint.go
+++ b/scheduler/filter/constraint.go
@@ -52,8 +52,8 @@ func (f *ConstraintFilter) Filter(config *cluster.ContainerConfig, nodes []*node
 	return nodes, nil
 }
 
-// Get a list of the constraints found in the container config.
-func (f *ConstraintFilter) GetAllFilters(config *cluster.ContainerConfig) ([]string, error) {
+// GetFilters returns a list of the constraints found in the container config.
+func (f *ConstraintFilter) GetFilters(config *cluster.ContainerConfig) ([]string, error) {
 	allConstraints := []string{}
 	constraints, err := parseExprs(config.Constraints())
 	if err != nil {
diff --git a/scheduler/filter/dependency.go b/scheduler/filter/dependency.go
index 0e8c078462..83a3c363fb 100644
--- a/scheduler/filter/dependency.go
+++ b/scheduler/filter/dependency.go
@@ -56,8 +56,8 @@ func (f *DependencyFilter) Filter(config *cluster.ContainerConfig, nodes []*node
 	return candidates, nil
 }
 
-// Get a list of the dependencies found in the container config.
-func (f *DependencyFilter) GetAllFilters(config *cluster.ContainerConfig) ([]string, error) {
+// GetFilters returns a list of the dependencies found in the container config.
+func (f *DependencyFilter) GetFilters(config *cluster.ContainerConfig) ([]string, error) {
 	dependencies := []string{}
 	for _, volume := range config.HostConfig.VolumesFrom {
 		dependencies = append(dependencies, fmt.Sprintf("--volumes-from=%s", volume))
@@ -73,7 +73,7 @@ func (f *DependencyFilter) GetAllFilters(config *cluster.ContainerConfig) ([]str
 
 // Get a string representation of the dependencies found in the container config.
 func (f *DependencyFilter) String(config *cluster.ContainerConfig) string {
-	dependencies, _ := f.GetAllFilters(config)
+	dependencies, _ := f.GetFilters(config)
 	return strings.Join(dependencies, " ")
 }
 
diff --git a/scheduler/filter/filter.go b/scheduler/filter/filter.go
index b414c24f72..e33a2f5832 100644
--- a/scheduler/filter/filter.go
+++ b/scheduler/filter/filter.go
@@ -2,6 +2,7 @@ package filter
 
 import (
 	"errors"
+	"fmt"
 
 	log "github.com/Sirupsen/logrus"
 	"github.com/docker/swarm/cluster"
@@ -16,7 +17,7 @@ type Filter interface {
 	Filter(*cluster.ContainerConfig, []*node.Node, bool) ([]*node.Node, error)
 
 	// Return a list of constraints/filters provided
-	GetAllFilters(*cluster.ContainerConfig) ([]string, error)
+	GetFilters(*cluster.ContainerConfig) ([]string, error)
 }
 
 var (
@@ -66,12 +67,31 @@ func ApplyFilters(filters []Filter, config *cluster.ContainerConfig, nodes []*no
 	for _, filter := range filters {
 		candidates, err = filter.Filter(config, candidates, soft)
 		if err != nil {
-			return nil, err
+			// special case for when no healthy nodes are found
+			if filter.Name() == "health" {
+				return nil, err
+			}
+			return nil, fmt.Errorf("Unable to find a node that satisfies the following conditions %s", listAllFilters(filters, config, filter.Name()))
 		}
 	}
 	return candidates, nil
 }
 
+// listAllFilters creates a string containing all applied filters
+func listAllFilters(filters []Filter, config *cluster.ContainerConfig, lastFilter string) string {
+	allFilters := ""
+	for _, filter := range filters {
+		list, err := filter.GetFilters(config)
+		if err == nil && len(list) > 0 {
+			allFilters = fmt.Sprintf("%s\n%v", allFilters, list)
+		}
+		if filter.Name() == lastFilter {
+			return allFilters
+		}
+	}
+	return allFilters
+}
+
 // List returns the names of all the available filters
 func List() []string {
 	names := []string{}
diff --git a/scheduler/filter/health.go b/scheduler/filter/health.go
index 12f805c710..04ee2c54f9 100644
--- a/scheduler/filter/health.go
+++ b/scheduler/filter/health.go
@@ -37,7 +37,7 @@ func (f *HealthFilter) Filter(_ *cluster.ContainerConfig, nodes []*node.Node, _
 	return result, nil
 }
 
-// Implements interface function, but currently redundant since we don't have node constraints
-func (f *HealthFilter) GetAllFilters(config *cluster.ContainerConfig) ([]string, error) {
+// GetFilters returns
+func (f *HealthFilter) GetFilters(config *cluster.ContainerConfig) ([]string, error) {
 	return nil, nil
 }
diff --git a/scheduler/filter/port.go b/scheduler/filter/port.go
index 2145ab44fd..3579b43456 100644
--- a/scheduler/filter/port.go
+++ b/scheduler/filter/port.go
@@ -119,8 +119,8 @@ func (p *PortFilter) compare(requested dockerclient.PortBinding, bindings map[st
 	return false
 }
 
-// Get a list of the port constraints found in the container config.
-func (p *PortFilter) GetAllFilters(config *cluster.ContainerConfig) ([]string, error) {
+// GetFilters returns a list of the port constraints found in the container config.
+func (p *PortFilter) GetFilters(config *cluster.ContainerConfig) ([]string, error) {
 	allPortConstraints := []string{}
 	if config.HostConfig.NetworkMode == "host" {
 		for port := range config.ExposedPorts {
@@ -131,7 +131,7 @@ func (p *PortFilter) GetAllFilters(config *cluster.ContainerConfig) ([]string, e
 
 	for _, port := range config.HostConfig.PortBindings {
 		for _, binding := range port {
-			allPortConstraints = append(allPortConstraints, fmt.Sprintf("port %s", binding.HostPort))
+			allPortConstraints = append(allPortConstraints, fmt.Sprintf("port %s (Bridge mode)", binding.HostPort))
 		}
 	}
 	return allPortConstraints, nil
diff --git a/test/integration/affinities.bats b/test/integration/affinities.bats
index 274dc95a52..78fdc4dacd 100644
--- a/test/integration/affinities.bats
+++ b/test/integration/affinities.bats
@@ -151,7 +151,8 @@ function teardown() {
 	# Run 3 tests in parallel. One of them must fail.
 	run parallel docker -H "${SWARM_HOSTS[0]}" run --label test.label=true -e affinity:test.label!=true -d busybox:latest ::: top top top
 	[ "$status" -ne 0 ]
-	[[ "${output}" == *'unable to find a node that satisfies test.label!=true'* ]]
+	[[ "${output}" == *"Unable to find a node that satisfies the following conditions"* ]]
+	[[ "${output}" == *"[test.label!=true (soft=false)]"* ]]
 
 	# Only 2 containers should have succeeded.
 	run docker_swarm ps -q
diff --git a/test/integration/build_with_filters.bats b/test/integration/build_with_filters.bats
index fb7d92b649..90ade594ef 100644
--- a/test/integration/build_with_filters.bats
+++ b/test/integration/build_with_filters.bats
@@ -17,7 +17,8 @@ function teardown() {
 
 	run docker_swarm build --build-arg="constraint:node==node-9" $TESTDATA/build
 	[ "$status" -eq 1 ]
-	[[ "$output" == *"Error response from daemon: unable to find a node that satisfies node==node-9"* ]]
+	[[ "${lines[1]}" == *"Unable to find a node that satisfies the following conditions"* ]]
+	[[ "${lines[2]}" == *"[node==node-9]"* ]]
 
 	run docker_swarm images -q
 	[ "$status" -eq 0 ]
diff --git a/test/integration/port-filters.bats b/test/integration/port-filters.bats
index 8044ba6730..b93f246d59 100644
--- a/test/integration/port-filters.bats
+++ b/test/integration/port-filters.bats
@@ -21,7 +21,8 @@ function teardown() {
 	# When trying to start the 3rd one, it should be error finding port 80.
 	run docker_swarm run -d --expose=80 --net=host busybox sh
 	[ "$status" -ne 0 ]
-	[[ "${lines[0]}" == *"unable to find a node with port 80/tcp available in the Host mode"* ]]
+	[[ "${lines[0]}" == *"Unable to find a node that satisfies the following conditions"* ]]
+	[[ "${lines[1]}" == *"[port 80/tcp (Host mode)]"* ]]
 
 	# And the number of running containers should be still 2.
 	run docker_swarm ps -n 2
@@ -40,7 +41,8 @@ function teardown() {
 	# When trying to start the 3rd one, it should be error finding port 80.
 	run docker_swarm run --expose=80 -p 80:80 busybox echo 3
 	[ "$status" -ne 0 ]
-	[[ "${lines[0]}" == *"unable to find a node with port 80 available"* ]]
+	[[ "${lines[0]}" == *"Unable to find a node that satisfies the following conditions"* ]]
+	[[ "${lines[1]}" == *"[port 80 (Bridge mode)]"* ]]
 
 	# And the number of running containers should be still 2.
 	run docker_swarm ps -n 2