Andrey Smirnov 3433fa13bf
feat: use container DNS when in container mode
More specifically, pick up `/etc/resolv.conf` contents by default when
in container mode, and use that as a base resolver for the host DNS.

Fixes #8303

Signed-off-by: Andrey Smirnov <andrey.smirnov@siderolabs.com>
2024-04-16 17:01:36 +04:00

124 lines
3.5 KiB
Go

// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
// Package docker implements Provisioner via docker.
package docker
import (
"context"
"fmt"
"net"
"strconv"
"github.com/docker/docker/client"
"github.com/siderolabs/talos/pkg/machinery/config/generate"
"github.com/siderolabs/talos/pkg/machinery/config/types/v1alpha1"
"github.com/siderolabs/talos/pkg/machinery/nethelpers"
"github.com/siderolabs/talos/pkg/provision"
)
type provisioner struct {
client *client.Client
mappedKubernetesPort, mappedTalosAPIPort int
}
func getAvailableTCPPort() (int, error) {
l, err := net.Listen("tcp", "127.0.0.1:0")
if err != nil {
return 0, err
}
_, portStr, err := net.SplitHostPort(l.Addr().String())
if err != nil {
l.Close() //nolint:errcheck
return 0, err
}
err = l.Close()
if err != nil {
return 0, err
}
port, err := strconv.Atoi(portStr)
if err != nil {
return 0, err
}
return port, nil
}
// NewProvisioner initializes docker provisioner.
func NewProvisioner(ctx context.Context) (provision.Provisioner, error) {
p := &provisioner{}
var err error
p.client, err = client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
if err != nil {
return nil, err
}
p.mappedKubernetesPort, err = getAvailableTCPPort()
if err != nil {
return nil, fmt.Errorf("failed to get available port for Kubernetes API: %w", err)
}
p.mappedTalosAPIPort, err = getAvailableTCPPort()
if err != nil {
return nil, fmt.Errorf("failed to get available port for Talos API: %w", err)
}
return p, nil
}
// Close and release resources.
func (p *provisioner) Close() error {
if p.client != nil {
return p.client.Close()
}
return nil
}
// GenOptions provides a list of additional config generate options.
func (p *provisioner) GenOptions(networkReq provision.NetworkRequest) []generate.Option {
return []generate.Option{
generate.WithNetworkOptions(
v1alpha1.WithNetworkInterfaceIgnore(v1alpha1.IfaceByName("eth0")),
),
generate.WithHostDNSForwardKubeDNSToHost(true),
}
}
// GetInClusterKubernetesControlPlaneEndpoint returns the Kubernetes control plane endpoint.
func (p *provisioner) GetInClusterKubernetesControlPlaneEndpoint(networkReq provision.NetworkRequest, controlPlanePort int) string {
// Docker doesn't have a loadbalancer, so use the first container IP.
return "https://" + nethelpers.JoinHostPort(networkReq.CIDRs[0].Addr().Next().Next().String(), controlPlanePort)
}
// GetExternalKubernetesControlPlaneEndpoint returns the Kubernetes control plane endpoint.
func (p *provisioner) GetExternalKubernetesControlPlaneEndpoint(provision.NetworkRequest, int) string {
// return a mapped to the localhost first container Kubernetes API endpoint.
return "https://" + nethelpers.JoinHostPort("127.0.0.1", p.mappedKubernetesPort)
}
// GetTalosAPIEndpoints returns a list of Talos API endpoints.
func (p *provisioner) GetTalosAPIEndpoints(provision.NetworkRequest) []string {
// return a mapped to the localhost first container Talos API endpoint.
return []string{nethelpers.JoinHostPort("127.0.0.1", p.mappedTalosAPIPort)}
}
// UserDiskName not implemented for docker.
func (p *provisioner) UserDiskName(index int) string {
return ""
}
// GetFirstInterface returns first network interface name.
func (p *provisioner) GetFirstInterface() v1alpha1.IfaceSelector {
return v1alpha1.IfaceByName("eth0")
}