feature: add container's network files

Signed-off-by: Eric Li <lcy041536@gmail.com>

cri/v1alpha1/cri_utils.go

@@ -216,6 +216,9 @@ func applySandboxSecurityContext(lc *runtime.LinuxPodSandboxConfig, config *apit
 
 // applySandboxLinuxOptions applies LinuxPodSandboxConfig to pouch's HostConfig and ContainerCreateConfig.
 func applySandboxLinuxOptions(hc *apitypes.HostConfig, lc *runtime.LinuxPodSandboxConfig, createConfig *apitypes.ContainerCreateConfig, image string) error {
+	// apply the sandbox network_mode, "none" is default.
+	hc.NetworkMode = namespaceModeNone
+
 	if lc == nil {
 		return nil
 	}

cri/v1alpha2/cri_utils.go

@@ -216,6 +216,9 @@ func applySandboxSecurityContext(lc *runtime.LinuxPodSandboxConfig, config *apit
 
 // applySandboxLinuxOptions applies LinuxPodSandboxConfig to pouch's HostConfig and ContainerCreateConfig.
 func applySandboxLinuxOptions(hc *apitypes.HostConfig, lc *runtime.LinuxPodSandboxConfig, createConfig *apitypes.ContainerCreateConfig, image string) error {
+	// apply the sandbox network_mode, "none" is default.
+	hc.NetworkMode = namespaceModeNone
+
 	if lc == nil {
 		return nil
 	}

daemon/mgr/container.go

@@ -250,6 +250,11 @@ func (mgr *ContainerManager) Create(ctx context.Context, name string, config *ty
 		return nil, errors.Wrap(errtypes.ErrAlreadyExisted, "container name: "+name)
 	}
 
+	// set hostname.
+	if config.Hostname.String() == "" {
+		config.Hostname = strfmt.Hostname(id)
+	}
+
 	// set container runtime
 	if config.HostConfig.Runtime == "" {
 		config.HostConfig.Runtime = mgr.Config.DefaultRuntime
@@ -322,13 +327,12 @@ func (mgr *ContainerManager) Create(ctx context.Context, name string, config *ty
 	networkMode := config.HostConfig.NetworkMode
 	if networkMode == "" {
 		config.HostConfig.NetworkMode = "bridge"
-		container.Config.NetworkDisabled = true
 	}
 	container.NetworkSettings = new(types.NetworkSettings)
 	if len(config.NetworkingConfig.EndpointsConfig) > 0 {
 		container.NetworkSettings.Networks = config.NetworkingConfig.EndpointsConfig
 	}
-	if container.NetworkSettings.Networks == nil && networkMode != "" && !IsContainer(networkMode) {
+	if container.NetworkSettings.Networks == nil && !IsContainer(config.HostConfig.NetworkMode) {
 		container.NetworkSettings.Networks = make(map[string]*types.EndpointSettings)
 		container.NetworkSettings.Networks[config.HostConfig.NetworkMode] = new(types.EndpointSettings)
 	}
@@ -454,33 +458,53 @@ func (mgr *ContainerManager) start(ctx context.Context, c *Container, detachKeys
 		c.ResolvConfPath = origContainer.ResolvConfPath
 		c.Config.Hostname = origContainer.Config.Hostname
 		c.Config.Domainname = origContainer.Config.Domainname
-	}
+	} else {
+		// initialise host network mode
+		if IsHost(networkMode) {
+			hostname, err := os.Hostname()
+			if err != nil {
+				return err
+			}
+			c.Config.Hostname = strfmt.Hostname(hostname)
+		}
 
-	// initialise host network mode
-	if IsHost(networkMode) {
-		hostname, err := os.Hostname()
-		if err != nil {
+		// build the network related path.
+		if err := mgr.buildNetworkRelatedPath(c); err != nil {
 			return err
 		}
-		c.Config.Hostname = strfmt.Hostname(hostname)
-	}
 
-	// initialise network endpoint
-	if c.NetworkSettings != nil {
-		for name, endpointSetting := range c.NetworkSettings.Networks {
-			endpoint := mgr.buildContainerEndpoint(c)
-			endpoint.Name = name
-			endpoint.EndpointConfig = endpointSetting
-			if _, err := mgr.NetworkMgr.EndpointCreate(ctx, endpoint); err != nil {
-				logrus.Errorf("failed to create endpoint: %v", err)
-				return err
+		// initialise network endpoint
+		if c.NetworkSettings != nil {
+			for name, endpointSetting := range c.NetworkSettings.Networks {
+				endpoint := mgr.buildContainerEndpoint(c)
+				endpoint.Name = name
+				endpoint.EndpointConfig = endpointSetting
+				if _, err := mgr.NetworkMgr.EndpointCreate(ctx, endpoint); err != nil {
+					logrus.Errorf("failed to create endpoint: %v", err)
+					return err
+				}
 			}
 		}
 	}
 
 	return mgr.createContainerdContainer(ctx, c)
 }
 
+// buildNetworkRelatedPath build the network related path.
+func (mgr *ContainerManager) buildNetworkRelatedPath(c *Container) error {
+	// set the hosts file path.
+	c.HostsPath = path.Join(mgr.Store.Path(c.ID), "hosts")
+
+	// set the resolv.conf file path.
+	c.ResolvConfPath = path.Join(mgr.Store.Path(c.ID), "resolv.conf")
+
+	// set the hostname file path.
+	c.HostnamePath = path.Join(mgr.Store.Path(c.ID), "hostname")
+
+	// write the hostname file, other files are filled by libnetwork.
+	return ioutil.WriteFile(c.HostnamePath, []byte(c.Config.Hostname+"\n"), 0644)
+}
+
 func (mgr *ContainerManager) createContainerdContainer(ctx context.Context, c *Container) error {
 	// CgroupParent from HostConfig will be first priority to use,
 	// then will be value from mgr.Config.CgroupParent

daemon/mgr/spec_mount.go

@@ -3,8 +3,12 @@ package mgr
 import (
 	"context"
 	"fmt"
+	"os"
+
+	"github.com/alibaba/pouch/apis/types"
 
 	specs "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/sirupsen/logrus"
 )
 
 func clearReadonly(m *specs.Mount) {
@@ -31,6 +35,11 @@ func setupMounts(ctx context.Context, c *Container, s *specs.Spec) error {
 		return nil
 	}
 	for _, mp := range c.Mounts {
+		if isSetupNetworkMount(mp, c) {
+			// ignore the network mount, we will handle it later.
+			continue
+		}
+
 		// check duplicate mountpoint
 		for _, sm := range mounts {
 			if sm.Destination == mp.Destination {
@@ -69,6 +78,10 @@ func setupMounts(ctx context.Context, c *Container, s *specs.Spec) error {
 			Options:     opts,
 		})
 	}
+
+	// generate network mounts.
+	mounts = append(mounts, generateNetworkMounts(c)...)
+
 	s.Mounts = mounts
 
 	if c.HostConfig.Privileged {
@@ -83,3 +96,73 @@ func setupMounts(ctx context.Context, c *Container, s *specs.Spec) error {
 	}
 	return nil
 }
+
+// generateNetworkMounts will generate network mounts.
+func generateNetworkMounts(c *Container) []specs.Mount {
+	mounts := make([]specs.Mount, 0)
+
+	if c.HostnamePath != "" {
+		_, err := os.Stat(c.HostnamePath)
+		if err != nil {
+			logrus.Warnf("HostnamePath set to %v, but stat error: %v, skip it", c.HostnamePath, err)
+		} else {
+			mounts = append(mounts, specs.Mount{
+				Source:      c.HostnamePath,
+				Destination: "/etc/hostname",
+				Type:        "bind",
+				Options:     []string{"rbind", "rprivate"},
+			})
+		}
+	}
+
+	if c.HostsPath != "" {
+		_, err := os.Stat(c.HostsPath)
+		if err != nil {
+			logrus.Warnf("HostsPath set to %v, but stat error: %v, skip it", c.HostsPath, err)
+		} else {
+			mounts = append(mounts, specs.Mount{
+				Source:      c.HostsPath,
+				Destination: "/etc/hosts",
+				Type:        "bind",
+				Options:     []string{"rbind", "rprivate"},
+			})
+		}
+	}
+
+	if c.ResolvConfPath != "" {
+		_, err := os.Stat(c.ResolvConfPath)
+		if err != nil {
+			logrus.Warnf("ResolvConfPath set to %v, but stat error: %v, skip it", c.ResolvConfPath, err)
+		} else {
+			mounts = append(mounts, specs.Mount{
+				Source:      c.ResolvConfPath,
+				Destination: "/etc/resolv.conf",
+				Type:        "bind",
+				Options:     []string{"rbind", "rprivate"},
+			})
+		}
+
+	}
+
+	return mounts
+}
+
+// isSetupNetworkMount checks whether set network mount.
+func isSetupNetworkMount(mount *types.MountPoint, c *Container) bool {
+	if mount.Destination == "/etc/hostname" {
+		c.HostnamePath = mount.Source
+		return true
+	}
+
+	if mount.Destination == "/etc/hosts" {
+		c.HostsPath = mount.Source
+		return true
+	}
+
+	if mount.Destination == "/etc/resolv.conf" {
+		c.ResolvConfPath = mount.Source
+		return true
+	}
+
+	return false
+}