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Merged
alicefr merged 1 commit into from
May 27, 2026
Merged

Use host networking for populator container to fix DNS in nested podman #16

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8 changes: 5 additions & 3 deletions hack/test-container-image.sh
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Original file line number Diff line number Diff line change
Expand Up @@ -90,9 +90,11 @@ run_test() {
"${bink_args[@]}" --help

echo "--- bink cluster start ---"
local verbose_flag=""
[ "${mode}" = "nested" ] && verbose_flag="-v"
"${bink_args[@]}" cluster start --cluster-name "${cluster_name}" --api-port 0 ${verbose_flag}
local start_extra_flags=""
if [ "${mode}" = "nested" ]; then
start_extra_flags="-v --host-network-populator"
fi
"${bink_args[@]}" cluster start --cluster-name "${cluster_name}" --api-port 0 ${start_extra_flags}

echo "--- bink api expose ---"
"${bink_args[@]}" api expose --cluster-name "${cluster_name}"
Expand Down
13 changes: 8 additions & 5 deletions internal/cli/cluster/start.go
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Expand Up @@ -28,14 +28,15 @@ func newStartCmd() *cobra.Command {
var memory int
var maxMemory int
var exposePath string
var hostNetworkPopulator bool

cmd := &cobra.Command{
Use: "start",
Short: "Start a new Kubernetes cluster",
Long: "Create network, control plane node, and initialize Kubernetes cluster with kubeadm",
RunE: func(cmd *cobra.Command, args []string) error {
logger := logrus.New()
return runStart(cmd.Context(), logger, nodeName, nodeImage, apiPort, memory, maxMemory, exposePath)
return runStart(cmd.Context(), logger, nodeName, nodeImage, apiPort, memory, maxMemory, exposePath, hostNetworkPopulator)
},
}

Expand All @@ -45,11 +46,12 @@ func newStartCmd() *cobra.Command {
cmd.Flags().IntVar(&memory, "memory", 0, "VM memory in MB (0 = use role default: 1900 for control-plane, 768 for worker)")
cmd.Flags().IntVar(&maxMemory, "max-memory", 0, "VM max memory in MB for balloon (0 = use role default: 4096 for control-plane, 2048 for worker)")
cmd.Flags().StringVar(&exposePath, "expose", "", "Expose API and save kubeconfig to PATH after cluster is up")
cmd.Flags().BoolVar(&hostNetworkPopulator, "host-network-populator", false, "Use host networking for the image populator container (fixes DNS in nested podman)")

return cmd
}

func runStart(ctx context.Context, logger *logrus.Logger, nodeName string, nodeImage string, apiPort int, memory int, maxMemory int, exposePath string) error {
func runStart(ctx context.Context, logger *logrus.Logger, nodeName string, nodeImage string, apiPort int, memory int, maxMemory int, exposePath string, hostNetworkPopulator bool) error {
logger.Info("=== Creating Kubernetes cluster ===")
logger.Info("")

Expand Down Expand Up @@ -102,9 +104,10 @@ func runStart(ctx context.Context, logger *logrus.Logger, nodeName string, nodeI

logger.Info("Step 5: Preparing cluster images volume...")
clusterMgr := cluster.New(cluster.Config{
Name: clusterName,
ControlPlane: nodeName,
Logger: logger,
Name: clusterName,
ControlPlane: nodeName,
HostNetworkPopulator: hostNetworkPopulator,
Logger: logger,
})

clusterImagesVolume, err := clusterMgr.EnsureImagesVolume(ctx, nodeImage)
Expand Down
13 changes: 8 additions & 5 deletions internal/cli/node/add.go
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Expand Up @@ -25,6 +25,7 @@ func newAddCmd() *cobra.Command {
var role string
var memory int
var maxMemory int
var hostNetworkPopulator bool

cmd := &cobra.Command{
Use: "add <node-name>",
Expand All @@ -33,7 +34,7 @@ func newAddCmd() *cobra.Command {
Args: cobra.ExactArgs(1),
RunE: func(cmd *cobra.Command, args []string) error {
logger := logrus.New()
return runAdd(cmd.Context(), args[0], controlPlane, nodeImage, role, memory, maxMemory, logger)
return runAdd(cmd.Context(), args[0], controlPlane, nodeImage, role, memory, maxMemory, hostNetworkPopulator, logger)
},
}

Expand All @@ -42,11 +43,12 @@ func newAddCmd() *cobra.Command {
cmd.Flags().StringVarP(&role, "role", "r", "worker", "Node role: worker or control-plane")
cmd.Flags().IntVar(&memory, "memory", 0, "VM memory in MB (0 = use role default: 1900 for control-plane, 768 for worker)")
cmd.Flags().IntVar(&maxMemory, "max-memory", 0, "VM max memory in MB for balloon (0 = use role default: 4096 for control-plane, 2048 for worker)")
cmd.Flags().BoolVar(&hostNetworkPopulator, "host-network-populator", false, "Use host networking for the image populator container (fixes DNS in nested podman)")

return cmd
}

func runAdd(ctx context.Context, nodeName, controlPlane, nodeImage, role string, memory int, maxMemory int, logger *logrus.Logger) error {
func runAdd(ctx context.Context, nodeName, controlPlane, nodeImage, role string, memory int, maxMemory int, hostNetworkPopulator bool, logger *logrus.Logger) error {
// Validate and convert role to boolean
var isControlPlane bool
switch role {
Expand Down Expand Up @@ -74,9 +76,10 @@ func runAdd(ctx context.Context, nodeName, controlPlane, nodeImage, role string,
// Ensure images volume exists for this node image version
logger.Infof("Step 0: Ensuring cluster images volume...")
clusterMgr := cluster.New(cluster.Config{
Name: clusterName,
ControlPlane: controlPlane,
Logger: logger,
Name: clusterName,
ControlPlane: controlPlane,
HostNetworkPopulator: hostNetworkPopulator,
Logger: logger,
})

clusterImagesVolume, err := clusterMgr.EnsureImagesVolume(ctx, nodeImage)
Expand Down
27 changes: 15 additions & 12 deletions internal/cluster/cluster.go
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Expand Up @@ -33,18 +33,20 @@ type PodmanClient interface {

// Cluster represents a Kubernetes cluster
type Cluster struct {
name string
controlPlane string
logger *logrus.Logger
podmanClient PodmanClient
name string
controlPlane string
hostNetworkPopulator bool
logger *logrus.Logger
podmanClient PodmanClient
}

// Config holds cluster configuration
type Config struct {
Name string // Cluster name (default: "bink")
ControlPlane string // Control plane node name (default: "node1")
Logger *logrus.Logger
PodmanClient PodmanClient
Name string // Cluster name (default: "bink")
ControlPlane string // Control plane node name (default: "node1")
HostNetworkPopulator bool // Use host networking for the image populator container
Logger *logrus.Logger
PodmanClient PodmanClient
}

// New creates a new Cluster
Expand All @@ -69,10 +71,11 @@ func New(cfg Config) *Cluster {
}

return &Cluster{
name: cfg.Name,
controlPlane: cfg.ControlPlane,
logger: cfg.Logger,
podmanClient: client,
name: cfg.Name,
controlPlane: cfg.ControlPlane,
hostNetworkPopulator: cfg.HostNetworkPopulator,
logger: cfg.Logger,
podmanClient: client,
}
}

Expand Down
8 changes: 6 additions & 2 deletions internal/cluster/images.go
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Expand Up @@ -191,11 +191,15 @@ func (c *Cluster) populateImagesVolume(ctx context.Context, volumeName, nodeImag
Destination: "/images",
}},
Volumes: []*specgen.NamedVolume{{Name: volumeName, Dest: "/var/lib/containers/storage"}},
CapAdd: []string{"SYS_ADMIN"},
Devices: []specs.LinuxDevice{{Path: "/dev/fuse"}},
CapAdd: []string{"SYS_ADMIN"},
Devices: []specs.LinuxDevice{{Path: "/dev/fuse"}},
SelinuxOpts: []string{"disable"},
}

if c.hostNetworkPopulator {
opts.Network = "host"
}

_, err := c.podmanClient.ContainerCreate(ctx, opts)
if err != nil {
return fmt.Errorf("starting populator container (another process may be populating): %w", err)
Expand Down
15 changes: 10 additions & 5 deletions internal/podman/client.go
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Expand Up @@ -246,11 +246,16 @@ func (c *Client) ContainerCreate(ctx context.Context, opts *ContainerCreateOptio
}
spec.Networks = opts.NetworkOptions
} else if opts.Network != "" {
spec.NetNS = specgen.Namespace{
NSMode: specgen.Bridge,
}
spec.Networks = map[string]nettypes.PerNetworkOptions{
opts.Network: {},
switch opts.Network {
case "host":
spec.NetNS = specgen.Namespace{NSMode: specgen.Host}
default:
spec.NetNS = specgen.Namespace{
NSMode: specgen.Bridge,
}
spec.Networks = map[string]nettypes.PerNetworkOptions{
opts.Network: {},
}
}
}

Expand Down
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