contd: parse startup.toml and update container data

fixes #319

we extract 3 things from statup.toml:
- entrypoint
- working dir
- enviroment variable

pkg/container.go

@@ -34,6 +34,8 @@ type Container struct {
 	RootFS string
 	// Env env variables to container in format {'KEY=VALUE', 'KEY2=VALUE2'}
 	Env []string
+	// WorkingDir of the entrypoint command
+	WorkingDir string
 	// Network network info for container
 	Network NetworkInfo
 	// Mounts extra mounts for container

pkg/container/container.go

@@ -3,19 +3,17 @@ package container
 import (
 	"context"
 
+	"github.com/BurntSushi/toml"
 	"github.com/pkg/errors"
 
 	"fmt"
-	"io"
 	"os"
 	"path"
 	"path/filepath"
 	"strings"
 	"syscall"
 	"time"
 
-	"github.com/BurntSushi/toml"
-
 	"github.com/rs/zerolog/log"
 
 	"github.com/opencontainers/runtime-spec/specs-go"
@@ -65,12 +63,7 @@ func New(root string, containerd string) pkg.ContainerModule {
 }
 
 // Run creates and starts a container
-// THIS IS A WIP Create action and it's not fully implemented atm
 func (c *containerModule) Run(ns string, data pkg.Container) (id pkg.ContainerID, err error) {
-	log.Info().
-		Str("namesapce", ns).
-		Str("data", fmt.Sprintf("%+v", data)).
-		Msgf("create new container")
 	// create a new client connected to the default socket path for containerd
 	client, err := containerd.New(c.containerd)
 	if err != nil {
@@ -92,6 +85,10 @@ func (c *containerModule) Run(ns string, data pkg.Container) (id pkg.ContainerID
 		return id, errors.Wrap(err, "failed to set resolv.conf")
 	}
 
+	if err := applyStartup(&data, filepath.Join(data.RootFS, ".startup.toml")); err != nil {
+		errors.Wrap(err, "error updating environment variable from startup file")
+	}
+
 	if data.Interactive {
 		if err := os.MkdirAll(filepath.Join(data.RootFS, "sandbox"), 0770); err != nil {
 			return id, err
@@ -118,6 +115,11 @@ func (c *containerModule) Run(ns string, data pkg.Container) (id pkg.ContainerID
 		oci.WithEnv(data.Env),
 		removeRunMount(),
 	}
+
+	if data.WorkingDir != "" {
+		opts = append(opts, oci.WithProcessCwd(data.WorkingDir))
+	}
+
 	if data.Interactive {
 		opts = append(
 			opts,
@@ -155,6 +157,11 @@ func (c *containerModule) Run(ns string, data pkg.Container) (id pkg.ContainerID
 		)
 	}
 
+	log.Info().
+		Str("namespace", ns).
+		Str("data", fmt.Sprintf("%+v", data)).
+		Msgf("create new container")
+
 	container, err := client.NewContainer(
 		ctx,
 		data.Name,
@@ -303,54 +310,71 @@ func (c *containerModule) Delete(ns string, id pkg.ContainerID) error {
 	return container.Delete(ctx)
 }
 
-// readEnvs reads the environment variable from the statup.toml file
-func readEnvs(r io.Reader) ([]string, error) {
-	env := struct {
-		Startup struct {
-			Entry struct {
-				Name string `json:"name"`
-				Args struct {
-					Name string            `json:"name"`
-					Dir  string            `json:"dir"`
-					Env  map[string]string `json:"env"`
-				} `json:"args"`
-			} `json:"entry"`
-		} `json:"startup"`
-	}{}
-	if _, err := toml.DecodeReader(r, &env); err != nil {
-		return nil, err
-	}
-
-	result := make([]string, 0, len(env.Startup.Entry.Args.Env))
-	for k, v := range env.Startup.Entry.Args.Env {
-		result = append(result, fmt.Sprintf("%s=%s", k, v))
-	}
-	return result, nil
+func (c *containerModule) ensureNamespace(ctx context.Context, client *containerd.Client, namespace string) error {
+	service := client.NamespaceService()
+	namespaces, err := service.List(ctx)
+	if err != nil {
+		return err
+	}
+
+	for _, ns := range namespaces {
+		if ns == namespace {
+			return nil
+		}
+	}
+
+	return service.Create(ctx, namespace, nil)
 }
 
-// mergeEnvs merge a into b
-// all the key from a will endup in b
-// if a key is present in both, key from a are kept
-func mergeEnvs(a, b []string) []string {
-	ma := make(map[string]string, len(a))
-	mb := make(map[string]string, len(b))
+func setResolvConf(root string) error {
+	const tmp = "nameserver 1.1.1.1\nnameserver 1.0.0.1\n2606:4700:4700::1111\nnameserver 2606:4700:4700::1001\n"
 
-	for _, s := range a {
-		ss := strings.SplitN(s, "=", 2)
-		ma[ss[0]] = ss[1]
+	path := filepath.Join(root, "etc/resolv.conf")
+	f, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE, 644)
+	if err != nil && !os.IsNotExist(err) {
+		return err
 	}
-	for _, s := range b {
-		ss := strings.SplitN(s, "=", 2)
-		mb[ss[0]] = ss[1]
+
+	defer f.Close()
+
+	if os.IsNotExist(err) {
+		_, err = f.WriteString(tmp)
+		return err
 	}
 
-	for ka, va := range ma {
-		mb[ka] = va
+	info, err := f.Stat()
+	if err != nil {
+		return err
 	}
+	if info.Size() == 0 {
+		_, err = f.WriteString(tmp)
+	}
+	return err
+}
 
-	result := make([]string, 0, len(mb))
-	for k, v := range mb {
-		result = append(result, fmt.Sprintf("%s=%s", k, v))
+func applyStartup(data *pkg.Container, path string) error {
+	f, err := os.Open(path)
+	if err == nil {
+		defer f.Close()
+		log.Info().Msg("startup file found")
+
+		startup := startup{}
+		if _, err := toml.DecodeReader(f, &startup); err != nil {
+			return err
+		}
+
+		entry, ok := startup.Entries["entry"]
+		if !ok {
+			return nil
+		}
+
+		data.Env = mergeEnvs(entry.Envs(), data.Env)
+		if data.Entrypoint == "" && entry.Entrypoint() != "" {
+			data.Entrypoint = entry.Entrypoint()
+		}
+		if data.WorkingDir == "" && entry.WorkingDir() != "" {
+			data.WorkingDir = entry.WorkingDir()
+		}
 	}
-	return result
+	return nil
 }

pkg/container/spec_opts.go → pkg/container/opts.go

@@ -2,14 +2,13 @@ package container
 
 import (
 	"context"
-	"os"
+
 	"path"
-	"path/filepath"
 
-	"github.com/containerd/containerd"
+	"github.com/opencontainers/runtime-spec/specs-go"
+
 	"github.com/containerd/containerd/containers"
 	"github.com/containerd/containerd/oci"
-	"github.com/opencontainers/runtime-spec/specs-go"
 )
 
 // withNetworkNamespace set the named network namespace to use for the container
@@ -57,22 +56,6 @@ func withAddedCapabilities(caps []string) oci.SpecOpts {
 	}
 }
 
-func (c *containerModule) ensureNamespace(ctx context.Context, client *containerd.Client, namespace string) error {
-	service := client.NamespaceService()
-	namespaces, err := service.List(ctx)
-	if err != nil {
-		return err
-	}
-
-	for _, ns := range namespaces {
-		if ns == namespace {
-			return nil
-		}
-	}
-
-	return service.Create(ctx, namespace, nil)
-}
-
 func removeRunMount() oci.SpecOpts {
 	return func(_ context.Context, _ oci.Client, _ *containers.Container, s *oci.Spec) error {
 		for i, mount := range s.Mounts {
@@ -84,29 +67,3 @@ func removeRunMount() oci.SpecOpts {
 		return nil
 	}
 }
-
-func setResolvConf(root string) error {
-	const tmp = "nameserver 1.1.1.1\nnameserver 1.0.0.1\n2606:4700:4700::1111\nnameserver 2606:4700:4700::1001\n"
-
-	path := filepath.Join(root, "etc/resolv.conf")
-	f, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE, 644)
-	if err != nil && !os.IsNotExist(err) {
-		return err
-	}
-
-	defer f.Close()
-
-	if os.IsNotExist(err) {
-		_, err = f.WriteString(tmp)
-		return err
-	}
-
-	info, err := f.Stat()
-	if err != nil {
-		return err
-	}
-	if info.Size() == 0 {
-		_, err = f.WriteString(tmp)
-	}
-	return err
-}

pkg/container/startup.go

@@ -0,0 +1,68 @@
+package container
+
+import (
+	"fmt"
+	"strings"
+)
+
+type startup struct {
+	Entries map[string]entry `toml:"startup"`
+}
+
+type entry struct {
+	Name string
+	Args args
+}
+
+type args struct {
+	Name string
+	Dir  string
+	Env  map[string]string
+}
+
+func (e entry) Entrypoint() string {
+	if e.Name == "core.system" ||
+		e.Name == "core.base" && e.Args.Name != "" {
+		return e.Args.Name
+	}
+	return ""
+}
+
+func (e entry) WorkingDir() string {
+	return e.Args.Dir
+}
+
+func (e entry) Envs() []string {
+	envs := make([]string, 0, len(e.Args.Env))
+	for k, v := range e.Args.Env {
+		envs = append(envs, fmt.Sprintf("%s=%s", k, v))
+	}
+	return envs
+}
+
+// mergeEnvs merge a into b
+// all the key from a will endup in b
+// if a key is present in both, key from a are kept
+func mergeEnvs(a, b []string) []string {
+	ma := make(map[string]string, len(a))
+	mb := make(map[string]string, len(b))
+
+	for _, s := range a {
+		ss := strings.SplitN(s, "=", 2)
+		ma[ss[0]] = ss[1]
+	}
+	for _, s := range b {
+		ss := strings.SplitN(s, "=", 2)
+		mb[ss[0]] = ss[1]
+	}
+
+	for ka, va := range ma {
+		mb[ka] = va
+	}
+
+	result := make([]string, 0, len(mb))
+	for k, v := range mb {
+		result = append(result, fmt.Sprintf("%s=%s", k, v))
+	}
+	return result
+}