mirror of
https://github.com/siderolabs/talos.git
synced 2025-08-20 22:21:13 +02:00
76c2038b13
This PR contains generic simple TCP loadbalancer code, and glue code for firecracker provisioner to use this loadbalancer. K8s control plane is passed through the load balancer, and Talos API is passed only to the init node (for now, as some APIs, including kubeconfig, don't work with non-init node). Signed-off-by: Andrey Smirnov <smirnov.andrey@gmail.com>
93 lines
2.4 KiB
Go
93 lines
2.4 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 loadbalancer provides simple TCP loadbalancer.
|
|
package loadbalancer
|
|
|
|
import (
|
|
"context"
|
|
"log"
|
|
"net"
|
|
|
|
"inet.af/tcpproxy"
|
|
|
|
"github.com/talos-systems/talos/internal/pkg/loadbalancer/upstream"
|
|
)
|
|
|
|
// TCP is a simple loadbalancer for TCP connections across a set of upstreams.
|
|
//
|
|
// Healthcheck is defined as TCP dial attempt by default.
|
|
//
|
|
// Zero value of TCP is a valid proxy, use `AddRoute` to install load balancer for
|
|
// address.
|
|
//
|
|
// Usage: call Run() to start lb and wait for shutdown, call Close() to shutdown lb.
|
|
type TCP struct {
|
|
tcpproxy.Proxy
|
|
}
|
|
|
|
type lbUpstream string
|
|
|
|
func (upstream lbUpstream) HealthCheck(ctx context.Context) error {
|
|
d := net.Dialer{}
|
|
|
|
c, err := d.DialContext(ctx, "tcp", string(upstream))
|
|
if err != nil {
|
|
log.Printf("healhcheck failed for %q: %s", string(upstream), err)
|
|
|
|
return err
|
|
}
|
|
|
|
return c.Close()
|
|
}
|
|
|
|
type lbTarget struct {
|
|
list *upstream.List
|
|
}
|
|
|
|
func (target *lbTarget) HandleConn(conn net.Conn) {
|
|
upstreamBackend, err := target.list.Pick()
|
|
if err != nil {
|
|
log.Printf("no upstreams available, closing connection from %s", conn.RemoteAddr())
|
|
conn.Close() //nolint: errcheck
|
|
|
|
return
|
|
}
|
|
|
|
upstreamAddr := upstreamBackend.(lbUpstream) //nolint: errcheck
|
|
|
|
log.Printf("proxying connection %s -> %s", conn.RemoteAddr(), string(upstreamAddr))
|
|
|
|
upstreamTarget := tcpproxy.To(string(upstreamAddr))
|
|
upstreamTarget.OnDialError = func(src net.Conn, dstDialErr error) {
|
|
src.Close() //nolint: errcheck
|
|
|
|
log.Printf("error dialing upstream %s: %s", string(upstreamAddr), dstDialErr)
|
|
|
|
target.list.Down(upstreamBackend)
|
|
}
|
|
|
|
upstreamTarget.HandleConn(conn)
|
|
}
|
|
|
|
// AddRoute installs load balancer route from listen address ipAddr to list of upstreams.
|
|
//
|
|
// TCP automatically does background health checks for the upstreams and picks only healthy
|
|
// ones. Healthcheck is simple Dial attempt.
|
|
func (t *TCP) AddRoute(ipPort string, upstreamAddrs []string, options ...upstream.ListOption) error {
|
|
upstreams := make([]upstream.Backend, len(upstreamAddrs))
|
|
for i := range upstreams {
|
|
upstreams[i] = lbUpstream(upstreamAddrs[i])
|
|
}
|
|
|
|
list, err := upstream.NewList(upstreams, options...)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
t.Proxy.AddRoute(ipPort, &lbTarget{list: list})
|
|
|
|
return nil
|
|
}
|