Move graph logic into package

Graph logic moves into depgraph package and makes internal
fields inaccessible. Completes feedback from @LucasRoesler
from previous PR where the dependency graph was added for 0.9.1

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

cloud-config.txt

@@ -16,13 +16,13 @@ runcmd:
 - mkdir -p /opt/cni/bin
 - curl -sSL https://github.com/containernetworking/plugins/releases/download/v0.8.5/cni-plugins-linux-amd64-v0.8.5.tgz | tar -xz -C /opt/cni/bin
 - mkdir -p /go/src/github.com/openfaas/
-- cd /go/src/github.com/openfaas/ && git clone https://github.com/openfaas/faasd
-- curl -fSLs "https://github.com/openfaas/faasd/releases/download/0.8.2/faasd" --output "/usr/local/bin/faasd" && chmod a+x "/usr/local/bin/faasd"
+- cd /go/src/github.com/openfaas/ && git clone https://github.com/openfaas/faasd && git checkout 0.9.0
+- curl -fSLs "https://github.com/openfaas/faasd/releases/download/0.9.0/faasd" --output "/usr/local/bin/faasd" && chmod a+x "/usr/local/bin/faasd"
 - cd /go/src/github.com/openfaas/faasd/ && /usr/local/bin/faasd install
 - systemctl status -l containerd --no-pager
 - journalctl -u faasd-provider --no-pager
 - systemctl status -l faasd-provider --no-pager
 - systemctl status -l faasd --no-pager
 - curl -sSLf https://cli.openfaas.com | sh
-- sleep 5 && journalctl -u faasd --no-pager
+- sleep 60 && journalctl -u faasd --no-pager
 - cat /var/lib/faasd/secrets/basic-auth-password | /usr/local/bin/faas-cli login --password-stdin

docker-compose.yaml

@@ -17,6 +17,7 @@ services:
         target: /run/secrets/basic-auth-user
     cap_add:
       - CAP_NET_RAW
+
   nats:
     image: docker.io/library/nats-streaming:0.11.2
     command:
@@ -25,6 +26,7 @@ services:
       - "8222"
       - "--store=memory"
       - "--cluster_id=faas-cluster"
+
   prometheus:
     image: docker.io/prom/prometheus:v2.14.0
     volumes:
@@ -33,6 +35,7 @@ services:
         target: /etc/prometheus/prometheus.yml
     cap_add:
       - CAP_NET_RAW
+
   gateway:
     image: "docker.io/openfaas/gateway:0.18.17${ARCH_SUFFIX}"
     environment:
@@ -58,6 +61,11 @@ services:
         target: /run/secrets/basic-auth-user
     cap_add:
       - CAP_NET_RAW
+    depends_on:
+      - basic-auth-plugin
+      - nats
+      - prometheus
+
   queue-worker:
     image: docker.io/openfaas/queue-worker:0.11.2
     environment:
@@ -80,3 +88,5 @@ services:
         target: /run/secrets/basic-auth-user
     cap_add:
       - CAP_NET_RAW
+    depends_on:
+      - nats

pkg/cninetwork/weave.go

@@ -18,19 +18,6 @@ type Dev struct {
 	CIDRs []*net.IPNet     `json:"CIDRs,omitempty"`
 }
 
-func linkToNetDev(link netlink.Link) (Dev, error) {
-	addrs, err := netlink.AddrList(link, netlink.FAMILY_V4)
-	if err != nil {
-		return Dev{}, err
-	}
-
-	netDev := Dev{Name: link.Attrs().Name, MAC: link.Attrs().HardwareAddr}
-	for _, addr := range addrs {
-		netDev.CIDRs = append(netDev.CIDRs, addr.IPNet)
-	}
-	return netDev, nil
-}
-
 // ConnectedToBridgeVethPeerIds returns peer indexes of veth links connected to
 // the given bridge. The peer index is used to query from a container netns
 // whether the container is connected to the bridge.

pkg/cninetwork/weave_linux.go

@@ -0,0 +1,19 @@
+// +build linux
+
+package cninetwork
+
+import "github.com/vishvananda/netlink"
+
+func linkToNetDev(link netlink.Link) (Dev, error) {
+
+	addrs, err := netlink.AddrList(link, netlink.FAMILY_V4)
+	if err != nil {
+		return Dev{}, err
+	}
+
+	netDev := Dev{Name: link.Attrs().Name, MAC: link.Attrs().HardwareAddr}
+	for _, addr := range addrs {
+		netDev.CIDRs = append(netDev.CIDRs, addr.IPNet)
+	}
+	return netDev, nil
+}

pkg/cninetwork/weave_mac.go

@@ -0,0 +1,10 @@
+// +build darwin
+
+package cninetwork
+
+import "github.com/vishvananda/netlink"
+
+func linkToNetDev(link netlink.Link) (Dev, error) {
+
+	return Dev{}, nil
+}

pkg/depgraph/depgraph.go

@@ -0,0 +1,106 @@
+package depgraph
+
+import "log"
+
+// Node represents a node in a Graph with
+// 0 to many edges
+type Node struct {
+	Name  string
+	Edges []*Node
+}
+
+// Graph is a collection of nodes
+type Graph struct {
+	nodes []*Node
+}
+
+func NewDepgraph() *Graph {
+	return &Graph{
+		nodes: []*Node{},
+	}
+}
+
+// Nodes returns the nodes within the graph
+func (g *Graph) Nodes() []*Node {
+	return g.nodes
+}
+
+// Contains returns true if the target Node is found
+// in its list
+func (g *Graph) Contains(target *Node) bool {
+	for _, g := range g.nodes {
+		if g.Name == target.Name {
+			return true
+		}
+	}
+
+	return false
+}
+
+// Add places a Node into the current Graph
+func (g *Graph) Add(target *Node) {
+	g.nodes = append(g.nodes, target)
+}
+
+// Remove deletes a target Node reference from the
+// list of nodes in the graph
+func (g *Graph) Remove(target *Node) {
+	var found *int
+	for i, n := range g.nodes {
+		if n == target {
+			found = &i
+			break
+		}
+	}
+
+	if found != nil {
+		g.nodes = append(g.nodes[:*found], g.nodes[*found+1:]...)
+	}
+}
+
+// Resolve retruns a list of node names in order of their dependencies.
+// A use case may be for determining the correct order to install
+// software packages, or to start services.
+// Based upon the algorithm described by Ferry Boender in the following article
+// https://www.electricmonk.nl/log/2008/08/07/dependency-resolving-algorithm/
+func (g *Graph) Resolve() []string {
+	resolved := &Graph{}
+	unresolved := &Graph{}
+	for _, node := range g.nodes {
+		resolve(node, resolved, unresolved)
+	}
+
+	order := []string{}
+
+	for _, node := range resolved.Nodes() {
+		order = append(order, node.Name)
+	}
+
+	return order
+}
+
+// resolve mutates the resolved graph for a given starting
+// node. The unresolved graph is used to detect a circular graph
+// error and will throw a panic. This can be caught with a resolve
+// in a go routine.
+func resolve(node *Node, resolved, unresolved *Graph) {
+	unresolved.Add(node)
+
+	for _, edge := range node.Edges {
+
+		if !resolved.Contains(edge) && unresolved.Contains(edge) {
+			log.Panicf("edge: %s may be a circular dependency", edge.Name)
+		}
+
+		resolve(edge, resolved, unresolved)
+	}
+
+	for _, r := range resolved.nodes {
+		if r.Name == node.Name {
+			return
+		}
+	}
+
+	resolved.Add(node)
+	unresolved.Remove(node)
+}

pkg/depgraph/depgraph_test.go

@@ -0,0 +1,41 @@
+package depgraph
+
+import "testing"
+
+func Test_RemoveMedial(t *testing.T) {
+	g := Graph{nodes: []*Node{}}
+	a := &Node{Name: "A"}
+	b := &Node{Name: "B"}
+	c := &Node{Name: "C"}
+
+	g.nodes = append(g.nodes, a)
+	g.nodes = append(g.nodes, b)
+	g.nodes = append(g.nodes, c)
+
+	g.Remove(b)
+
+	for _, n := range g.nodes {
+		if n.Name == b.Name {
+			t.Fatalf("Found deleted node: %s", n.Name)
+		}
+	}
+}
+
+func Test_RemoveFinal(t *testing.T) {
+	g := Graph{nodes: []*Node{}}
+	a := &Node{Name: "A"}
+	b := &Node{Name: "B"}
+	c := &Node{Name: "C"}
+
+	g.nodes = append(g.nodes, a)
+	g.nodes = append(g.nodes, b)
+	g.nodes = append(g.nodes, c)
+
+	g.Remove(c)
+
+	for _, n := range g.nodes {
+		if n.Name == c.Name {
+			t.Fatalf("Found deleted node: %s", c.Name)
+		}
+	}
+}

pkg/deployment_order.go

@@ -0,0 +1,41 @@
+package pkg
+
+import (
+	"log"
+
+	"github.com/openfaas/faasd/pkg/depgraph"
+)
+
+func buildDeploymentOrder(svcs []Service) []string {
+
+	graph := buildServiceGraph(svcs)
+
+	order := graph.Resolve()
+
+	log.Printf("Start-up order:\n")
+	for _, node := range order {
+		log.Printf("- %s\n", node)
+	}
+
+	return order
+}
+
+func buildServiceGraph(svcs []Service) *depgraph.Graph {
+	graph := depgraph.NewDepgraph()
+
+	nodeMap := map[string]*depgraph.Node{}
+	for _, s := range svcs {
+		n := &depgraph.Node{Name: s.Name}
+		nodeMap[s.Name] = n
+		graph.Add(n)
+
+	}
+
+	for _, s := range svcs {
+		for _, d := range s.DependsOn {
+			nodeMap[s.Name].Edges = append(nodeMap[s.Name].Edges, nodeMap[d])
+		}
+	}
+
+	return graph
+}

pkg/deployment_order_test.go

@@ -0,0 +1,224 @@
+package pkg
+
+import (
+	"log"
+	"testing"
+)
+
+func Test_buildDeploymentOrder_ARequiresB(t *testing.T) {
+	svcs := []Service{
+		{
+			Name:      "A",
+			DependsOn: []string{"B"},
+		},
+		{
+			Name:      "B",
+			DependsOn: []string{},
+		},
+	}
+
+	order := buildDeploymentOrder(svcs)
+
+	if len(order) < len(svcs) {
+		t.Fatalf("length of order too short: %d", len(order))
+	}
+
+	got := order[0]
+	want := "B"
+	if got != want {
+		t.Fatalf("%s should be last to be installed, but was: %s", want, got)
+	}
+}
+
+func Test_buildDeploymentOrder_ARequiresBAndC(t *testing.T) {
+	svcs := []Service{
+		{
+			Name:      "A",
+			DependsOn: []string{"B", "C"},
+		},
+		{
+			Name:      "B",
+			DependsOn: []string{},
+		},
+		{
+			Name:      "C",
+			DependsOn: []string{},
+		},
+	}
+
+	order := buildDeploymentOrder(svcs)
+
+	if len(order) < len(svcs) {
+		t.Fatalf("length of order too short: %d", len(order))
+	}
+
+	a := indexStr(order, "a")
+	b := indexStr(order, "b")
+	c := indexStr(order, "c")
+
+	if a > b {
+		t.Fatalf("a should be after dependencies")
+	}
+	if a > c {
+		t.Fatalf("a should be after dependencies")
+	}
+
+}
+
+func Test_buildDeploymentOrder_ARequiresBRequiresC(t *testing.T) {
+	svcs := []Service{
+		{
+			Name:      "A",
+			DependsOn: []string{"B"},
+		},
+		{
+			Name:      "B",
+			DependsOn: []string{"C"},
+		},
+		{
+			Name:      "C",
+			DependsOn: []string{},
+		},
+	}
+
+	order := buildDeploymentOrder(svcs)
+
+	if len(order) < len(svcs) {
+		t.Fatalf("length of order too short: %d", len(order))
+	}
+
+	got := order[0]
+	want := "C"
+	if got != want {
+		t.Fatalf("%s should be last to be installed, but was: %s", want, got)
+	}
+	got = order[1]
+	want = "B"
+	if got != want {
+		t.Fatalf("%s should be last to be installed, but was: %s", want, got)
+	}
+	got = order[2]
+	want = "A"
+	if got != want {
+		t.Fatalf("%s should be last to be installed, but was: %s", want, got)
+	}
+}
+
+func Test_buildDeploymentOrderCircularARequiresBRequiresA(t *testing.T) {
+	svcs := []Service{
+		{
+			Name:      "A",
+			DependsOn: []string{"B"},
+		},
+		{
+			Name:      "B",
+			DependsOn: []string{"A"},
+		},
+	}
+
+	defer func() { recover() }()
+
+	buildDeploymentOrder(svcs)
+
+	t.Fatalf("did not panic as expected")
+}
+
+func Test_buildDeploymentOrderComposeFile(t *testing.T) {
+	// svcs := []Service{}
+	file, err := LoadComposeFileWithArch("../", "docker-compose.yaml", func() (string, string) {
+		return "x86_64", "Linux"
+	})
+
+	if err != nil {
+		t.Fatalf("unable to load compose file: %s", err)
+	}
+
+	svcs, err := ParseCompose(file)
+	if err != nil {
+		t.Fatalf("unable to parse compose file: %s", err)
+	}
+
+	for _, s := range svcs {
+		log.Printf("Service: %s\n", s.Name)
+		for _, d := range s.DependsOn {
+			log.Printf("Link: %s => %s\n", s.Name, d)
+		}
+	}
+
+	order := buildDeploymentOrder(svcs)
+
+	if len(order) < len(svcs) {
+		t.Fatalf("length of order too short: %d", len(order))
+	}
+
+	queueWorker := indexStr(order, "queue-worker")
+	nats := indexStr(order, "nats")
+	gateway := indexStr(order, "gateway")
+	prometheus := indexStr(order, "prometheus")
+
+	if prometheus > gateway {
+		t.Fatalf("Prometheus order was after gateway, and should be before")
+	}
+	if nats > gateway {
+		t.Fatalf("NATS order was after gateway, and should be before")
+	}
+	if nats > queueWorker {
+		t.Fatalf("NATS order was after queue-worker, and should be before")
+	}
+}
+
+func Test_buildDeploymentOrderOpenFaaS(t *testing.T) {
+	svcs := []Service{
+		{
+			Name:      "queue-worker",
+			DependsOn: []string{"nats"},
+		},
+		{
+			Name:      "prometheus",
+			DependsOn: []string{},
+		},
+		{
+			Name:      "gateway",
+			DependsOn: []string{"prometheus", "nats", "basic-auth-plugin"},
+		},
+		{
+			Name:      "basic-auth-plugin",
+			DependsOn: []string{},
+		},
+		{
+			Name:      "nats",
+			DependsOn: []string{},
+		},
+	}
+
+	order := buildDeploymentOrder(svcs)
+
+	if len(order) < len(svcs) {
+		t.Fatalf("length of order too short: %d", len(order))
+	}
+
+	queueWorker := indexStr(order, "queue-worker")
+	nats := indexStr(order, "nats")
+	gateway := indexStr(order, "gateway")
+	prometheus := indexStr(order, "prometheus")
+
+	if prometheus > gateway {
+		t.Fatalf("Prometheus order was after gateway, and should be before")
+	}
+	if nats > gateway {
+		t.Fatalf("NATS order was after gateway, and should be before")
+	}
+	if nats > queueWorker {
+		t.Fatalf("NATS order was after queue-worker, and should be before")
+	}
+}
+
+func indexStr(st []string, t string) int {
+	for n, s := range st {
+		if s == t {
+			return n
+		}
+
+	}
+	return -1
+}

pkg/supervisor.go

@@ -34,12 +34,13 @@ const (
 )
 
 type Service struct {
-	Image  string
-	Env    []string
-	Name   string
-	Mounts []Mount
-	Caps   []string
-	Args   []string
+	Image     string
+	Env       []string
+	Name      string
+	Mounts    []Mount
+	Caps      []string
+	Args      []string
+	DependsOn []string
 }
 
 type Mount struct {
@@ -92,7 +93,7 @@ func (s *Supervisor) Start(svcs []Service) error {
 	images := map[string]containerd.Image{}
 
 	for _, svc := range svcs {
-		fmt.Printf("Preparing: %s with image: %s\n", svc.Name, svc.Image)
+		fmt.Printf("Preparing %s with image: %s\n", svc.Name, svc.Image)
 
 		img, err := service.PrepareImage(ctx, s.client, svc.Image, defaultSnapshotter, faasServicesPullAlways)
 		if err != nil {
@@ -104,12 +105,26 @@ func (s *Supervisor) Start(svcs []Service) error {
 	}
 
 	for _, svc := range svcs {
-		fmt.Printf("Reconciling: %s\n", svc.Name)
-
+		fmt.Printf("Removing old container for: %s\n", svc.Name)
 		containerErr := service.Remove(ctx, s.client, svc.Name)
 		if containerErr != nil {
 			return containerErr
 		}
+	}
+
+	order := buildDeploymentOrder(svcs)
+
+	for _, key := range order {
+
+		var svc *Service
+		for _, s := range svcs {
+			if s.Name == key {
+				svc = &s
+				break
+			}
+		}
+
+		fmt.Printf("Starting: %s\n", svc.Name)
 
 		image := images[svc.Name]
 
@@ -123,7 +138,6 @@ func (s *Supervisor) Start(svcs []Service) error {
 					Options:     []string{"rbind", "rw"},
 				})
 			}
-
 		}
 
 		mounts = append(mounts, specs.Mount{
@@ -153,11 +167,11 @@ func (s *Supervisor) Start(svcs []Service) error {
 		)
 
 		if containerCreateErr != nil {
-			log.Printf("Error creating container %s\n", containerCreateErr)
+			log.Printf("Error creating container: %s\n", containerCreateErr)
 			return containerCreateErr
 		}
 
-		log.Printf("Created container %s\n", newContainer.ID())
+		log.Printf("Created container: %s\n", newContainer.ID())
 
 		task, err := newContainer.NewTask(ctx, cio.NewCreator(cio.WithStdio))
 		if err != nil {
@@ -176,6 +190,7 @@ func (s *Supervisor) Start(svcs []Service) error {
 		if err != nil {
 			return err
 		}
+
 		log.Printf("%s has IP: %s\n", newContainer.ID(), ip.String())
 
 		hosts, _ := ioutil.ReadFile("hosts")
@@ -277,10 +292,11 @@ func ParseCompose(config *compose.Config) ([]Service, error) {
 			Name:  s.Name,
 			Image: s.Image,
 			// ShellCommand is just an alias of string slice
-			Args:   []string(s.Command),
-			Caps:   s.CapAdd,
-			Env:    env,
-			Mounts: mounts,
+			Args:      []string(s.Command),
+			Caps:      s.CapAdd,
+			Env:       env,
+			Mounts:    mounts,
+			DependsOn: s.DependsOn,
 		}
 	}
 
@@ -289,6 +305,12 @@ func ParseCompose(config *compose.Config) ([]Service, error) {
 
 // LoadComposeFile is a helper method for loading a docker-compose file
 func LoadComposeFile(wd string, file string) (*compose.Config, error) {
+	return LoadComposeFileWithArch(wd, file, env.GetClientArch)
+}
+
+// LoadComposeFileWithArch is a helper method for loading a docker-compose file
+func LoadComposeFileWithArch(wd string, file string, archGetter ArchGetter) (*compose.Config, error) {
+
 	file = path.Join(wd, file)
 	b, err := ioutil.ReadFile(file)
 	if err != nil {
@@ -300,7 +322,7 @@ func LoadComposeFile(wd string, file string) (*compose.Config, error) {
 		return nil, err
 	}
 
-	archSuffix, err := GetArchSuffix(env.GetClientArch)
+	archSuffix, err := GetArchSuffix(archGetter)
 	if err != nil {
 		return nil, err
 	}

pkg/supervisor_test.go

@@ -7,8 +7,10 @@ import (
 )
 
 func Test_ParseCompose(t *testing.T) {
+
 	wd := "testdata"
-	expected := map[string]Service{
+
+	want := map[string]Service{
 		"basic-auth-plugin": {
 			Name:  "basic-auth-plugin",
 			Image: "docker.io/openfaas/basic-auth-plugin:0.18.17",
@@ -73,7 +75,8 @@ func Test_ParseCompose(t *testing.T) {
 					Dest: path.Join("/run/secrets", "basic-auth-user"),
 				},
 			},
-			Caps: []string{"CAP_NET_RAW"},
+			Caps:      []string{"CAP_NET_RAW"},
+			DependsOn: []string{"nats"},
 		},
 		"queue-worker": {
 			Name: "queue-worker",
@@ -103,32 +106,39 @@ func Test_ParseCompose(t *testing.T) {
 		},
 	}
 
-	compose, err := LoadComposeFile(wd, "docker-compose.yaml")
+	compose, err := LoadComposeFileWithArch(wd, "docker-compose.yaml", func() (string, string) { return "x86_64", "Linux" })
 	if err != nil {
-		t.Fatalf("can not read docker-compose fixture: %s", err)
+		t.Fatalf("can't read docker-compose file: %s", err)
 	}
 
 	services, err := ParseCompose(compose)
 	if err != nil {
-		t.Fatalf("can not parse compose services: %s", err)
+		t.Fatalf("can't parse compose services: %s", err)
 	}
 
-	if len(services) != len(expected) {
-		t.Fatalf("expected: %d services, got: %d", len(expected), len(services))
+	if len(services) != len(want) {
+		t.Fatalf("want: %d services, got: %d", len(want), len(services))
 	}
 
 	for _, service := range services {
-		exp, ok := expected[service.Name]
+		exp, ok := want[service.Name]
+
+		if service.Name == "gateway" {
+			if len(service.DependsOn) == 0 {
+				t.Fatalf("gateway should have at least one depends_on entry")
+			}
+		}
+
 		if !ok {
-			t.Fatalf("unexpected service: %s", service.Name)
+			t.Fatalf("incorrect service: %s", service.Name)
 		}
 
 		if service.Name != exp.Name {
-			t.Fatalf("incorrect service Name:\n\texpected: %s,\n\tgot: %s", exp.Name, service.Name)
+			t.Fatalf("incorrect service Name:\n\twant: %s,\n\tgot: %s", exp.Name, service.Name)
 		}
 
 		if service.Image != exp.Image {
-			t.Fatalf("incorrect service Image:\n\texpected: %s,\n\tgot: %s", exp.Image, service.Image)
+			t.Fatalf("incorrect service Image:\n\twant: %s,\n\tgot: %s", exp.Image, service.Image)
 		}
 
 		equalStringSlice(t, exp.Env, service.Env)
@@ -136,41 +146,41 @@ func Test_ParseCompose(t *testing.T) {
 		equalStringSlice(t, exp.Args, service.Args)
 
 		if !reflect.DeepEqual(exp.Mounts, service.Mounts) {
-			t.Fatalf("incorrect service Mounts:\n\texpected: %+v,\n\tgot: %+v", exp.Mounts, service.Mounts)
+			t.Fatalf("incorrect service Mounts:\n\twant: %+v,\n\tgot: %+v", exp.Mounts, service.Mounts)
 		}
 	}
 }
 
-func equalStringSlice(t *testing.T, expected, found []string) {
+func equalStringSlice(t *testing.T, want, found []string) {
 	t.Helper()
-	if (expected == nil) != (found == nil) {
-		t.Fatalf("unexpected nil slice: expected %+v, got %+v", expected, found)
+	if (want == nil) != (found == nil) {
+		t.Fatalf("unexpected nil slice: want %+v, got %+v", want, found)
 	}
 
-	if len(expected) != len(found) {
-		t.Fatalf("unequal slice length: expected %+v, got %+v", expected, found)
+	if len(want) != len(found) {
+		t.Fatalf("unequal slice length: want %+v, got %+v", want, found)
 	}
 
-	for i := range expected {
-		if expected[i] != found[i] {
-			t.Fatalf("unexpected value at postition %d: expected %s, got %s", i, expected[i], found[i])
+	for i := range want {
+		if want[i] != found[i] {
+			t.Fatalf("unexpected value at postition %d: want %s, got %s", i, want[i], found[i])
 		}
 	}
 }
 
-func equalMountSlice(t *testing.T, expected, found []Mount) {
+func equalMountSlice(t *testing.T, want, found []Mount) {
 	t.Helper()
-	if (expected == nil) != (found == nil) {
-		t.Fatalf("unexpected nil slice: expected %+v, got %+v", expected, found)
+	if (want == nil) != (found == nil) {
+		t.Fatalf("unexpected nil slice: want %+v, got %+v", want, found)
 	}
 
-	if len(expected) != len(found) {
-		t.Fatalf("unequal slice length: expected %+v, got %+v", expected, found)
+	if len(want) != len(found) {
+		t.Fatalf("unequal slice length: want %+v, got %+v", want, found)
 	}
 
-	for i := range expected {
-		if !reflect.DeepEqual(expected[i], found[i]) {
-			t.Fatalf("unexpected value at postition %d: expected %s, got %s", i, expected[i], found[i])
+	for i := range want {
+		if !reflect.DeepEqual(want[i], found[i]) {
+			t.Fatalf("unexpected value at postition %d: want %s, got %s", i, want[i], found[i])
 		}
 	}
 }
@@ -178,7 +188,7 @@ func equalMountSlice(t *testing.T, expected, found []Mount) {
 func Test_GetArchSuffix(t *testing.T) {
 	cases := []struct {
 		name      string
-		expected  string
+		want      string
 		foundArch string
 		foundOS   string
 		err       string
@@ -192,37 +202,37 @@ func Test_GetArchSuffix(t *testing.T) {
 			name:      "x86 has no suffix",
 			foundOS:   "Linux",
 			foundArch: "x86_64",
-			expected:  "",
+			want:      "",
 		},
 		{
 			name:      "unknown arch has no suffix",
 			foundOS:   "Linux",
 			foundArch: "anything_else",
-			expected:  "",
+			want:      "",
 		},
 		{
 			name:      "armhf has armhf suffix",
 			foundOS:   "Linux",
 			foundArch: "armhf",
-			expected:  "-armhf",
+			want:      "-armhf",
 		},
 		{
 			name:      "armv7l has armhf suffix",
 			foundOS:   "Linux",
 			foundArch: "armv7l",
-			expected:  "-armhf",
+			want:      "-armhf",
 		},
 		{
 			name:      "arm64 has arm64 suffix",
 			foundOS:   "Linux",
 			foundArch: "arm64",
-			expected:  "-arm64",
+			want:      "-arm64",
 		},
 		{
 			name:      "aarch64 has arm64 suffix",
 			foundOS:   "Linux",
 			foundArch: "aarch64",
-			expected:  "-arm64",
+			want:      "-arm64",
 		},
 	}
 
@@ -231,15 +241,15 @@ func Test_GetArchSuffix(t *testing.T) {
 
 			suffix, err := GetArchSuffix(testArchGetter(tc.foundArch, tc.foundOS))
 			if tc.err != "" && err == nil {
-				t.Fatalf("expected error %s but got nil", tc.err)
+				t.Fatalf("want error %s but got nil", tc.err)
 			} else if tc.err != "" && err.Error() != tc.err {
-				t.Fatalf("expected error %s, got %s", tc.err, err.Error())
+				t.Fatalf("want error %s, got %s", tc.err, err.Error())
 			} else if tc.err == "" && err != nil {
 				t.Fatalf("unexpected error %s", err.Error())
 			}
 
-			if suffix != tc.expected {
-				t.Fatalf("expected suffix %s, got %s", tc.expected, suffix)
+			if suffix != tc.want {
+				t.Fatalf("want suffix %s, got %s", tc.want, suffix)
 			}
 		})
 	}

pkg/testdata/docker-compose.yaml

@@ -1,12 +1,12 @@
 version: "3.7"
 services:
   basic-auth-plugin:
-    image: docker.io/openfaas/basic-auth-plugin:0.18.17
+    image: "docker.io/openfaas/basic-auth-plugin:0.18.17${ARCH_SUFFIX}"
     environment:
-      port: "8080"
-      secret_mount_path: "/run/secrets"
-      user_filename: "basic-auth-user"
-      pass_filename: "basic-auth-password"
+      - port=8080
+      - secret_mount_path=/run/secrets
+      - user_filename=basic-auth-user
+      - pass_filename=basic-auth-password
     volumes:
       # we assume cwd == /var/lib/faasd
       - type: bind
@@ -17,6 +17,7 @@ services:
         target: /run/secrets/basic-auth-user
     cap_add:
       - CAP_NET_RAW
+
   nats:
     image: docker.io/library/nats-streaming:0.11.2
     command:
@@ -25,6 +26,7 @@ services:
       - "8222"
       - "--store=memory"
       - "--cluster_id=faas-cluster"
+
   prometheus:
     image: docker.io/prom/prometheus:v2.14.0
     volumes:
@@ -33,21 +35,22 @@ services:
         target: /etc/prometheus/prometheus.yml
     cap_add:
       - CAP_NET_RAW
+
   gateway:
-    image: docker.io/openfaas/gateway:0.18.17
+    image: "docker.io/openfaas/gateway:0.18.17${ARCH_SUFFIX}"
     environment:
-      basic_auth: "true"
-      functions_provider_url: "http://faasd-provider:8081/"
-      direct_functions: "false"
-      read_timeout: "60s"
-      write_timeout: "60s"
-      upstream_timeout: "65s"
-      faas_nats_address: "nats"
-      faas_nats_port: "4222"
-      auth_proxy_url: "http://basic-auth-plugin:8080/validate"
-      auth_proxy_pass_body: "false"
-      secret_mount_path: "/run/secrets"
-      scale_from_zero: "true"
+      - basic_auth=true
+      - functions_provider_url=http://faasd-provider:8081/
+      - direct_functions=false
+      - read_timeout=60s
+      - write_timeout=60s
+      - upstream_timeout=65s
+      - faas_nats_address=nats
+      - faas_nats_port=4222
+      - auth_proxy_url=http://basic-auth-plugin:8080/validate
+      - auth_proxy_pass_body=false
+      - secret_mount_path=/run/secrets
+      - scale_from_zero=true
     volumes:
       # we assume cwd == /var/lib/faasd
       - type: bind
@@ -58,18 +61,23 @@ services:
         target: /run/secrets/basic-auth-user
     cap_add:
       - CAP_NET_RAW
+    depends_on:
+      - basic-auth-plugin
+      - nats
+      - prometheus
+
   queue-worker:
     image: docker.io/openfaas/queue-worker:0.11.2
     environment:
-      faas_nats_address: "nats"
-      faas_nats_port: "4222"
-      gateway_invoke: "true"
-      faas_gateway_address: "gateway"
-      ack_wait: "5m5s"
-      max_inflight: "1"
-      write_debug: "false"
-      basic_auth: "true"
-      secret_mount_path: "/run/secrets"
+      - faas_nats_address=nats
+      - faas_nats_port=4222
+      - gateway_invoke=true
+      - faas_gateway_address=gateway
+      - ack_wait=5m5s
+      - max_inflight=1
+      - write_debug=false
+      - basic_auth=true
+      - secret_mount_path=/run/secrets
     volumes:
       # we assume cwd == /var/lib/faasd
       - type: bind
@@ -80,3 +88,5 @@ services:
         target: /run/secrets/basic-auth-user
     cap_add:
       - CAP_NET_RAW
+    depends_on:
+      - nats