cleanup container name logic

cmd/nixose/main.go

@@ -44,7 +44,7 @@ func main() {
 
 	start := time.Now()
 	g := nixose.Generator{
-		Project:      nixose.NewProject(*project, *projectSeparator),
+		Project:      nixose.NewProjectWithSeparator(*project, *projectSeparator),
 		Runtime:      containerRuntime,
 		Paths:        paths,
 		EnvFiles:     envFiles,

compose.go

@@ -181,36 +181,37 @@ func (g *Generator) Run(ctx context.Context) (*NixContainerConfig, error) {
 	}, nil
 }
 
-func (g *Generator) postProcessContainers(containers []NixContainer) {
+func (g *Generator) postProcessContainers(containers []*NixContainer) {
 	serviceToContainer := make(map[string]*NixContainer)
 	for _, c := range containers {
-		serviceToContainer[c.service.Name] = &c
+		serviceToContainer[c.service.Name] = c
 	}
+
 	for _, c := range containers {
 		if networkMode := c.service.NetworkMode; strings.HasPrefix(networkMode, "service:") {
 			targetService := strings.Split(networkMode, ":")[1]
 			targetContainerName := serviceToContainer[targetService].Name
 			c.ExtraOptions = append(c.ExtraOptions, "--network=container:"+targetContainerName)
 		}
-	}
-}
 
-func (g *Generator) buildNixContainer(service types.ServiceConfig) NixContainer {
-	dependsOn := service.GetDependencies()
-	if g.Project != nil {
-		for i := range dependsOn {
-			dependsOn[i] = g.Project.With(dependsOn[i])
+		dependsOn := c.service.GetDependencies()
+		for i, service := range dependsOn {
+			dependsOn[i] = serviceToContainer[service].Name
 		}
+		c.DependsOn = dependsOn
+
+		// Drop the reference to the service at the end of post-processing. This allows GC to
+		// kick in and free the service allocation.
+		c.service = nil
 	}
+}
 
+func (g *Generator) buildNixContainer(service types.ServiceConfig) *NixContainer {
 	var name string
 	if service.ContainerName != "" {
 		name = service.ContainerName
 	} else {
-		// TODO(aksiksi): We should try to use the same convention as Docker Compose
-		// when container_name is not set.
-		// See: https://github.com/docker/compose/issues/6316
-		name = service.Name
+		name = g.Project.With(service.Name)
 	}
 
 	systemdConfig, err := parseRestartPolicyAndSystemdLabels(&service)
@@ -219,8 +220,7 @@ func (g *Generator) buildNixContainer(service types.ServiceConfig) NixContainer
 		panic(err)
 	}
 
-	c := NixContainer{
-		Project:       g.Project,
+	c := &NixContainer{
 		Runtime:       g.Runtime,
 		Name:          name,
 		Image:         service.Image,
@@ -230,7 +230,6 @@ func (g *Generator) buildNixContainer(service types.ServiceConfig) NixContainer
 		Volumes:       make(map[string]string),
 		Networks:      maps.Keys(service.Networks),
 		SystemdConfig: systemdConfig,
-		DependsOn:     dependsOn,
 		AutoStart:     g.AutoStart,
 		service:       &service,
 	}
@@ -245,7 +244,7 @@ func (g *Generator) buildNixContainer(service types.ServiceConfig) NixContainer
 	for _, name := range c.Networks {
 		networkName := g.Project.With(name)
 		c.ExtraOptions = append(c.ExtraOptions, fmt.Sprintf("--network=%s", networkName))
-		// Allow other containers to use bare container name as an alias even when a project is set.
+		// Allow other containers to use service name as an alias when a project is set.
 		c.ExtraOptions = append(c.ExtraOptions, fmt.Sprintf("--network-alias=%s", service.Name))
 	}
 
@@ -298,45 +297,43 @@ func (g *Generator) buildNixContainer(service types.ServiceConfig) NixContainer
 	return c
 }
 
-func (g *Generator) buildNixContainers() []NixContainer {
-	var containers []NixContainer
+func (g *Generator) buildNixContainers() []*NixContainer {
+	var containers []*NixContainer
 	for _, s := range g.composeProject.Services {
 		containers = append(containers, g.buildNixContainer(s))
 	}
-	slices.SortFunc(containers, func(c1, c2 NixContainer) int {
+	slices.SortFunc(containers, func(c1, c2 *NixContainer) int {
 		return cmp.Compare(c1.Name, c2.Name)
 	})
 	return containers
 }
 
-func (g *Generator) buildNixNetworks(containers []NixContainer) []NixNetwork {
-	var networks []NixNetwork
+func (g *Generator) buildNixNetworks(containers []*NixContainer) []*NixNetwork {
+	var networks []*NixNetwork
 	for name, network := range g.composeProject.Networks {
-		n := NixNetwork{
-			Project: g.Project,
+		n := &NixNetwork{
 			Runtime: g.Runtime,
-			Name:    name,
+			Name:    g.Project.With(name),
 			Labels:  network.Labels,
 		}
 		// Keep track of all containers that are in this network.
 		for _, c := range containers {
 			if slices.Contains(c.Networks, name) {
-				n.Containers = append(n.Containers, fmt.Sprintf("%s-%s", g.Runtime, g.Project.With(c.Name)))
+				n.Containers = append(n.Containers, fmt.Sprintf("%s-%s", g.Runtime, c.Name))
 			}
 		}
 		networks = append(networks, n)
 	}
-	slices.SortFunc(networks, func(n1, n2 NixNetwork) int {
+	slices.SortFunc(networks, func(n1, n2 *NixNetwork) int {
 		return cmp.Compare(n1.Name, n2.Name)
 	})
 	return networks
 }
 
-func (g *Generator) buildNixVolumes(containers []NixContainer) []NixVolume {
-	var volumes []NixVolume
+func (g *Generator) buildNixVolumes(containers []*NixContainer) []*NixVolume {
+	var volumes []*NixVolume
 	for name, volume := range g.composeProject.Volumes {
-		v := NixVolume{
-			Project:    g.Project,
+		v := &NixVolume{
 			Runtime:    g.Runtime,
 			Name:       name,
 			Driver:     volume.Driver,
@@ -364,12 +361,12 @@ func (g *Generator) buildNixVolumes(containers []NixContainer) []NixVolume {
 		// Keep track of all containers that use this named volume.
 		for _, c := range containers {
 			if _, ok := c.Volumes[name]; ok {
-				v.Containers = append(v.Containers, fmt.Sprintf("%s-%s", g.Runtime, g.Project.With(c.Name)))
+				v.Containers = append(v.Containers, fmt.Sprintf("%s-%s", g.Runtime, c.Name))
 			}
 		}
 		volumes = append(volumes, v)
 	}
-	slices.SortFunc(volumes, func(n1, n2 NixVolume) int {
+	slices.SortFunc(volumes, func(n1, n2 *NixVolume) int {
 		return cmp.Compare(n1.Name, n2.Name)
 	})
 	return volumes

nixose.go

@@ -8,7 +8,7 @@ import (
 	"github.com/compose-spec/compose-go/types"
 )
 
-const DefaultProjectSeparator = "-"
+const DefaultProjectSeparator = "_"
 
 type ContainerRuntime int
 
@@ -36,7 +36,14 @@ type Project struct {
 	separator string
 }
 
-func NewProject(name, separator string) *Project {
+func NewProject(name string) *Project {
+	if name == "" {
+		return nil
+	}
+	return &Project{Name: name, separator: DefaultProjectSeparator}
+}
+
+func NewProjectWithSeparator(name, separator string) *Project {
 	if name == "" {
 		return nil
 	}
@@ -53,16 +60,21 @@ func (p *Project) With(name string) string {
 	return fmt.Sprintf("%s%s%s", p.Name, p.separator, name)
 }
 
+func (p *Project) WithSeparator(name, separator string) string {
+	if p == nil {
+		return name
+	}
+	return fmt.Sprintf("%s%s%s", p.Name, separator, name)
+}
+
 type NixNetwork struct {
-	Project    *Project
 	Runtime    ContainerRuntime
 	Name       string
 	Labels     map[string]string
 	Containers []string
 }
 
 type NixVolume struct {
-	Project    *Project
 	Runtime    ContainerRuntime
 	Name       string
 	Driver     string
@@ -88,7 +100,6 @@ type NixContainerSystemdConfig struct {
 
 // https://search.nixos.org/options?channel=unstable&from=0&size=50&sort=relevance&type=packages&query=oci-container
 type NixContainer struct {
-	Project       *Project
 	Runtime       ContainerRuntime
 	Name          string
 	Image         string
@@ -105,15 +116,16 @@ type NixContainer struct {
 	AutoStart     bool
 
 	// Original Docker Compose service.
+	// Used for post-processing containers and reset to nil right afterwards.
 	service *types.ServiceConfig
 }
 
 type NixContainerConfig struct {
 	Project    *Project
 	Runtime    ContainerRuntime
-	Containers []NixContainer
-	Networks   []NixNetwork
-	Volumes    []NixVolume
+	Containers []*NixContainer
+	Networks   []*NixNetwork
+	Volumes    []*NixVolume
 }
 
 func (c NixContainerConfig) String() string {

nixose_test.go

@@ -47,6 +47,33 @@ func TestDocker(t *testing.T) {
 	}
 }
 
+func TestDocker_WithProject(t *testing.T) {
+	ctx := context.Background()
+	composePath, envFilePath, outFilePath := getPaths(t)
+	g := Generator{
+		Project:  NewProject("myproject"),
+		Runtime:  ContainerRuntimeDocker,
+		Paths:    []string{composePath},
+		EnvFiles: []string{envFilePath},
+	}
+	c, err := g.Run(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	wantOutput, err := os.ReadFile(outFilePath)
+	if err != nil {
+		t.Fatal(err)
+	}
+	got, want := c.String(), string(wantOutput)
+	if *update {
+		if err := os.WriteFile(outFilePath, []byte(got), 0644); err != nil {
+			t.Fatal(err)
+		}
+	} else if diff := cmp.Diff(want, got); diff != "" {
+		t.Errorf("output diff: %s\n", diff)
+	}
+}
+
 func TestPodman(t *testing.T) {
 	ctx := context.Background()
 	composePath, envFilePath, outFilePath := getPaths(t)
@@ -72,3 +99,30 @@ func TestPodman(t *testing.T) {
 		t.Errorf("output diff: %s\n", diff)
 	}
 }
+
+func TestPodman_WithProject(t *testing.T) {
+	ctx := context.Background()
+	composePath, envFilePath, outFilePath := getPaths(t)
+	g := Generator{
+		Project:  NewProject("myproject"),
+		Runtime:  ContainerRuntimePodman,
+		Paths:    []string{composePath},
+		EnvFiles: []string{envFilePath},
+	}
+	c, err := g.Run(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	wantOutput, err := os.ReadFile(outFilePath)
+	if err != nil {
+		t.Fatal(err)
+	}
+	got, want := c.String(), string(wantOutput)
+	if *update {
+		if err := os.WriteFile(outFilePath, []byte(got), 0644); err != nil {
+			t.Fatal(err)
+		}
+	} else if diff := cmp.Diff(want, got); diff != "" {
+		t.Errorf("output diff: %s\n", diff)
+	}
+}

templates/container.nix.tmpl

@@ -1,6 +1,5 @@
-{{- $name := .Project.With .Name -}}
 {{- $runtime := .Runtime | printf "%s" -}}
-virtualisation.oci-containers.containers."{{$name}}" = {
+virtualisation.oci-containers.containers."{{.Name}}" = {
   image = "{{.Image}}";
 
   {{- if .Environment}}
@@ -68,7 +67,7 @@ virtualisation.oci-containers.containers."{{$name}}" = {
   {{- end}}
 };
 {{- if .SystemdConfig}}
-systemd.services."{{$runtime}}-{{$name}}" = {
+systemd.services."{{$runtime}}-{{.Name}}" = {
   {{- if .SystemdConfig.Service}}
   serviceConfig = {
   {{- range $k, $v := .SystemdConfig.Service}}

templates/network.nix.tmpl

@@ -1,16 +1,15 @@
-{{- $name := .Project.With .Name -}}
 {{- $runtime := .Runtime | printf "%s" -}}
 {{- $labels := mapToRepeatedKeyValFlag "--label" .Labels -}}
-systemd.services."create-{{$runtime}}-network-{{$name}}" = {
+systemd.services."create-{{$runtime}}-network-{{.Name}}" = {
   serviceConfig.Type = "oneshot";
   path = [ pkgs.{{$runtime}} ];
   {{- if eq $runtime "docker"}}
   script = ''
-    docker network inspect {{$name}} || docker network create {{$name}}{{ $labels | join " "}}
+    docker network inspect {{.Name}} || docker network create {{.Name}}{{ $labels | join " "}}
   '';
   {{- else}}
   script = ''
-    podman network create {{$name}} --opt isolate=true --ignore{{ $labels | join " "}}
+    podman network create {{.Name}} --opt isolate=true --ignore{{ $labels | join " "}}
   '';
   {{- end}}
   {{- if .Containers}}