open-nomad/client/fingerprint/bridge_linux.go

129 lines
3.2 KiB
Go

// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: MPL-2.0
//go:build linux
package fingerprint
import (
"bufio"
"fmt"
"os"
"regexp"
"strconv"
"github.com/hashicorp/go-multierror"
"github.com/hashicorp/nomad/nomad/structs"
"github.com/shirou/gopsutil/v3/host"
)
const bridgeKernelModuleName = "bridge"
const (
dynamicModuleRe = `%s\s+.*$`
builtinModuleRe = `.+/%s.ko$`
dependsModuleRe = `.+/%s.ko(\.xz)?:.*$`
)
func (f *BridgeFingerprint) Fingerprint(req *FingerprintRequest, resp *FingerprintResponse) error {
if err := f.detect(bridgeKernelModuleName); err != nil {
f.logger.Warn("failed to detect bridge kernel module, bridge network mode disabled", "error", err)
return nil
}
resp.NodeResources = &structs.NodeResources{
Networks: []*structs.NetworkResource{{
Mode: "bridge",
}},
NodeNetworks: []*structs.NodeNetworkResource{{
Mode: "bridge",
Device: req.Config.BridgeNetworkName,
}},
}
resp.AddAttribute("nomad.bridge.hairpin_mode",
strconv.FormatBool(req.Config.BridgeNetworkHairpinMode))
resp.Detected = true
return nil
}
func (f *BridgeFingerprint) regexp(pattern, module string) *regexp.Regexp {
return regexp.MustCompile(fmt.Sprintf(pattern, module))
}
func (f *BridgeFingerprint) detect(module string) error {
// accumulate errors from every place we might find the module
var errs error
// Check if the module is in /sys/modules
sysfsModulePath := fmt.Sprintf("/sys/module/%s", module)
if err := f.findDir(sysfsModulePath); err != nil {
errs = multierror.Append(errs, err)
} else {
return nil
}
// check if the module has been dynamically loaded
dynamicPath := "/proc/modules"
if err := f.searchFile(module, dynamicPath, f.regexp(dynamicModuleRe, module)); err != nil {
errs = multierror.Append(errs, err)
} else {
return nil
}
// will need kernel info to look for builtin and unloaded modules
hostInfo, err := host.Info()
if err != nil {
return err
}
// check if the module is builtin to the kernel
builtinPath := fmt.Sprintf("/lib/modules/%s/modules.builtin", hostInfo.KernelVersion)
if err := f.searchFile(module, builtinPath, f.regexp(builtinModuleRe, module)); err != nil {
errs = multierror.Append(errs, err)
} else {
return nil
}
// check if the module is dynamic but unloaded (will have a dep entry)
dependsPath := fmt.Sprintf("/lib/modules/%s/modules.dep", hostInfo.KernelVersion)
if err := f.searchFile(module, dependsPath, f.regexp(dependsModuleRe, module)); err != nil {
errs = multierror.Append(errs, err)
} else {
return nil
}
return errs
}
func (f *BridgeFingerprint) findDir(dirname string) error {
if _, err := os.Stat(dirname); err != nil {
return fmt.Errorf("failed to find %s: %v", dirname, err)
} else {
return nil
}
}
func (f *BridgeFingerprint) searchFile(module, filename string, re *regexp.Regexp) error {
file, err := os.Open(filename)
if err != nil {
return fmt.Errorf("failed to open %s: %v", filename, err)
}
defer func() {
_ = file.Close()
}()
scanner := bufio.NewScanner(file)
for scanner.Scan() {
if re.MatchString(scanner.Text()) {
return nil // found the module!
}
}
if err := scanner.Err(); err != nil {
return fmt.Errorf("failed to scan %s: %v", filename, err)
}
return fmt.Errorf("module %s not in %s", module, filename)
}