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Update dnsmasq operator to use embeded files
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This cleans up the dnsmasq controller package by moving all go templates into the dnsmasq/scripts directory.
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@s-fairchild @cadenmarchese
s-fairchild authored and cadenmarchese committed Aug 25, 2023
1 parent f9df85d commit 3f62386
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Showing 8 changed files with 196 additions and 169 deletions.
2 changes: 1 addition & 1 deletion pkg/api/defaults.go
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Original file line number Diff line number Diff line change
Expand Up @@ -79,7 +79,7 @@ func DefaultOperatorFlags() OperatorFlags {
"aro.banner.enabled": flagFalse,
"aro.checker.enabled": flagTrue,
"aro.dnsmasq.enabled": flagTrue,
"aro.restartdnsmasq.enabled": flagFalse,
"aro.restartdnsmasq.enabled": flagTrue,
"aro.genevalogging.enabled": flagTrue,
"aro.imageconfig.enabled": flagTrue,
"aro.ingress.enabled": flagTrue,
Expand Down
134 changes: 17 additions & 117 deletions pkg/operator/controllers/dnsmasq/dnsmasq.go
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Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@ package dnsmasq

import (
"bytes"
_ "embed"
"encoding/json"
"fmt"
"text/template"
Expand All @@ -17,105 +18,17 @@ import (
"k8s.io/apimachinery/pkg/runtime"
)

var t = template.Must(template.New("").Parse(`
{{ define "dnsmasq.conf" }}
resolv-file=/etc/resolv.conf.dnsmasq
strict-order
address=/api.{{ .ClusterDomain }}/{{ .APIIntIP }}
address=/api-int.{{ .ClusterDomain }}/{{ .APIIntIP }}
address=/.apps.{{ .ClusterDomain }}/{{ .IngressIP }}
{{- range $GatewayDomain := .GatewayDomains }}
address=/{{ $GatewayDomain }}/{{ $.GatewayPrivateEndpointIP }}
{{- end }}
user=dnsmasq
group=dnsmasq
no-hosts
cache-size=0
{{ end }}
{{ define "dnsmasq.service" }}
[Unit]
Description=DNS caching server.
After=network-online.target
Before=bootkube.service
[Service]
# ExecStartPre will create a copy of the customer current resolv.conf file and make it upstream DNS.
# This file is a product of user DNS settings on the VNET. We will replace this file to point to
# dnsmasq instance on the node. dnsmasq will inject certain dns records we need and forward rest of the queries to
# resolv.conf.dnsmasq upstream customer dns.
ExecStartPre=/bin/bash /usr/local/bin/aro-dnsmasq-pre.sh
ExecStart=/usr/sbin/dnsmasq -k
ExecStopPost=/bin/bash -c '/bin/mv /etc/resolv.conf.dnsmasq /etc/resolv.conf; /usr/sbin/restorecon /etc/resolv.conf'
Restart=always
[Install]
WantedBy=multi-user.target
{{ end }}
{{ define "aro-dnsmasq-pre.sh" }}
#!/bin/bash
set -euo pipefail
# This bash script is a part of the ARO DnsMasq configuration
# It's deployed as part of the 99-aro-dns-* machine config
# See https://github.com/Azure/ARO-RP
# This file can be rerun and the effect is idempotent, output might change if the DHCP configuration changes
TMPSELFRESOLV=$(mktemp)
TMPNETRESOLV=$(mktemp)
echo "# Generated for dnsmasq.service - should point to self" > $TMPSELFRESOLV
echo "# Generated for dnsmasq.service - should contain DHCP configured DNS" > $TMPNETRESOLV
if nmcli device show br-ex; then
echo "OVN mode - br-ex device exists"
#getting DNS search strings
SEARCH_RAW=$(nmcli --get IP4.DOMAIN device show br-ex)
#getting DNS servers
NAMESERVER_RAW=$(nmcli --get IP4.DNS device show br-ex | tr -s " | " "\n")
LOCAL_IPS_RAW=$(nmcli --get IP4.ADDRESS device show br-ex)
else
NETDEV=$(nmcli --get device connection show --active | head -n 1) #there should be only one active device
echo "OVS SDN mode - br-ex not found, using device $NETDEV"
SEARCH_RAW=$(nmcli --get IP4.DOMAIN device show $NETDEV)
NAMESERVER_RAW=$(nmcli --get IP4.DNS device show $NETDEV | tr -s " | " "\n")
LOCAL_IPS_RAW=$(nmcli --get IP4.ADDRESS device show $NETDEV)
fi
#search line
echo "search $SEARCH_RAW" | tr '\n' ' ' >> $TMPNETRESOLV
echo "" >> $TMPNETRESOLV
echo "search $SEARCH_RAW" | tr '\n' ' ' >> $TMPSELFRESOLV
echo "" >> $TMPSELFRESOLV
#nameservers as separate lines
echo "$NAMESERVER_RAW" | while read -r line
do
echo "nameserver $line" >> $TMPNETRESOLV
done
# device IPs are returned in address/mask format
echo "$LOCAL_IPS_RAW" | while read -r line
do
echo "nameserver $line" | cut -d'/' -f 1 >> $TMPSELFRESOLV
done
# done, copying files to destination locations and cleaning up
/bin/cp $TMPNETRESOLV /etc/resolv.conf.dnsmasq
chmod 0744 /etc/resolv.conf.dnsmasq
/bin/cp $TMPSELFRESOLV /etc/resolv.conf
/usr/sbin/restorecon /etc/resolv.conf
/bin/rm $TMPNETRESOLV
/bin/rm $TMPSELFRESOLV
{{ end }}
`))
const (
configFileName = "dnsmasq.conf"
unitFileName = "dnsmasq.service"
prescriptFileName = "aro-dnsmasq-pre.sh"
)

func config(clusterDomain, apiIntIP, ingressIP string, gatewayDomains []string, gatewayPrivateEndpointIP string) ([]byte, error) {
t := template.Must(template.New(configFileName).Parse(preScriptFile))
buf := &bytes.Buffer{}

err := t.ExecuteTemplate(buf, "dnsmasq.conf", &struct {
err := t.ExecuteTemplate(buf, configFileName, &struct {
ClusterDomain string
APIIntIP string
IngressIP string
Expand All @@ -136,9 +49,10 @@ func config(clusterDomain, apiIntIP, ingressIP string, gatewayDomains []string,
}

func service() (string, error) {
t := template.Must(template.New(unitFileName).Parse(unitFile))
buf := &bytes.Buffer{}

err := t.ExecuteTemplate(buf, "dnsmasq.service", nil)
err := t.ExecuteTemplate(buf, unitFileName, nil)
if err != nil {
return "", err
}
Expand All @@ -147,9 +61,10 @@ func service() (string, error) {
}

func startpre() ([]byte, error) {
t := template.Must(template.New(prescriptFileName).Parse(configFile))
buf := &bytes.Buffer{}

err := t.ExecuteTemplate(buf, "aro-dnsmasq-pre.sh", nil)
err := t.ExecuteTemplate(buf, prescriptFileName, nil)
if err != nil {
return nil, err
}
Expand Down Expand Up @@ -183,7 +98,7 @@ func ignition2Config(clusterDomain, apiIntIP, ingressIP string, gatewayDomains [
Node: ign2types.Node{
Filesystem: "root",
Overwrite: to.BoolPtr(true),
Path: "/etc/dnsmasq.conf",
Path: "/etc/" + configFileName,
User: &ign2types.NodeUser{
Name: "root",
},
Expand All @@ -199,7 +114,7 @@ func ignition2Config(clusterDomain, apiIntIP, ingressIP string, gatewayDomains [
Node: ign2types.Node{
Filesystem: "root",
Overwrite: to.BoolPtr(true),
Path: "/usr/local/bin/aro-dnsmasq-pre.sh",
Path: "/usr/local/bin/" + prescriptFileName,
User: &ign2types.NodeUser{
Name: "root",
},
Expand All @@ -218,34 +133,19 @@ func ignition2Config(clusterDomain, apiIntIP, ingressIP string, gatewayDomains [
{
Contents: service,
Enabled: to.BoolPtr(true),
Name: "dnsmasq.service",
Name: unitFileName,
},
},
},
}

if restartDnsmasq {
restartDnsmasqRaw, err := nmDispatcherRestartDnsmasq()
restartDnsmasqScript, err := nmDispatcherRestartDnsmasq()
if err != nil {
return nil, err
}

ign.Storage.Files = append(ign.Storage.Files, ign2types.File{
Node: ign2types.Node{
Filesystem: "root",
Overwrite: to.BoolPtr(true),
Path: "/etc/NetworkManager/dispatcher.d/99-dnsmasq-restart",
User: &ign2types.NodeUser{
Name: "root",
},
},
FileEmbedded1: ign2types.FileEmbedded1{
Contents: ign2types.FileContents{
Source: dataurl.EncodeBytes(restartDnsmasqRaw),
},
Mode: to.IntPtr(0744),
},
})
ign.Storage.Files = append(ign.Storage.Files, restartScriptIgnFile(restartDnsmasqScript))
}

return ign, nil
Expand Down
77 changes: 26 additions & 51 deletions pkg/operator/controllers/dnsmasq/dnsmasq_restart.go
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Original file line number Diff line number Diff line change
Expand Up @@ -6,66 +6,41 @@ package dnsmasq
import (
"bytes"
"text/template"
)

const restartTemplate = `{{ define "99-dnsmasq-restart" }}
#!/bin/sh
# This is a NetworkManager dispatcher script to restart dnsmasq
# in the event of a network interface change (e. g. host servicing event https://learn.microsoft.com/en-us/azure/developer/intro/hosting-apps-on-azure)
# this will restart dnsmasq, reapplying our /etc/resolv.conf file and overwriting any modifications made by NetworkManager
interface=$1
action=$2
log() {
logger -i "$0" -t '99-DNSMASQ-RESTART SCRIPT' "$@"
}
# log dns configuration information relevant to SRE while troubleshooting
# The line break used here is important for formatting
check_dns_files() {
log "/etc/resolv.conf contents
$(cat /etc/resolv.conf)"
log "$(echo -n \"/etc/resolv.conf file metadata: \") $(ls -lZ /etc/resolv.conf)"
log "/etc/resolv.conf.dnsmasq contents

$(cat /etc/resolv.conf.dnsmasq)"
log "$(echo -n "/etc/resolv.conf.dnsmasq file metadata: ") $(ls -lZ /etc/resolv.conf.dnsmasq)"
}
if [[ $interface == eth* && $action == "up" ]] || [[ $interface == eth* && $action == "down" ]] || [[ $interface == enP* && $action == "up" ]] || [[ $interface == enP* && $action == "down" ]]; then
log "$action happened on $interface, connection state is now $CONNECTIVITY_STATE"
log "Pre dnsmasq restart file information"
check_dns_files
log "restarting dnsmasq now"
if systemctl try-restart dnsmasq --wait; then
log "dnsmasq successfully restarted"
log "Post dnsmasq restart file information"
check_dns_files
else
log "failed to restart dnsmasq"
fi
fi
"github.com/Azure/go-autorest/autorest/to"
ign2types "github.com/coreos/ignition/config/v2_2/types"
"github.com/vincent-petithory/dataurl"
)

exit 0
{{ end }}
`

func restartDnsmasqTemplate() *template.Template {
return template.Must(template.New("").Parse(restartTemplate))
}
const restartScriptFileName = "99-dnsmasq-restart"

func nmDispatcherRestartDnsmasq() ([]byte, error) {
t := template.Must(template.New(restartScriptFileName).Parse(restartScript))
buf := &bytes.Buffer{}

err := restartDnsmasqTemplate().ExecuteTemplate(buf, "99-dnsmasq-restart", nil)
err := t.ExecuteTemplate(buf, restartScriptFileName, nil)
if err != nil {
return nil, err
}

return buf.Bytes(), nil
}

func restartScriptIgnFile(data []byte) ign2types.File {
return ign2types.File{
Node: ign2types.Node{
Filesystem: "root",
Overwrite: to.BoolPtr(true),
Path: "/etc/NetworkManager/dispatcher.d/" + restartScriptFileName,
User: &ign2types.NodeUser{
Name: "root",
},
},
FileEmbedded1: ign2types.FileEmbedded1{
Contents: ign2types.FileContents{
Source: dataurl.EncodeBytes(data),
},
Mode: to.IntPtr(0744),
},
}
}
18 changes: 18 additions & 0 deletions pkg/operator/controllers/dnsmasq/scripts.go
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Original file line number Diff line number Diff line change
@@ -0,0 +1,18 @@
package dnsmasq

// Copyright (c) Microsoft Corporation.
// Licensed under the Apache License 2.0.

import _ "embed"

//go:embed scripts/dnsmasq.conf.gotmpl
var configFile string

//go:embed scripts/dnsmasq.service.gotmpl
var unitFile string

//go:embed scripts/aro-dnsmasq-pre.sh.gotmpl
var preScriptFile string

//go:embed scripts/99-dnsmasq-restart.gotmpl
var restartScript string
45 changes: 45 additions & 0 deletions pkg/operator/controllers/dnsmasq/scripts/99-dnsmasq-restart.gotmpl
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Original file line number Diff line number Diff line change
@@ -0,0 +1,45 @@
{{ define "99-dnsmasq-restart" }}
#!/bin/sh
# This is a NetworkManager dispatcher script to restart dnsmasq
# in the event of a network interface change (e. g. host servicing event https://learn.microsoft.com/en-us/azure/developer/intro/hosting-apps-on-azure)
# this will restart dnsmasq, reapplying our /etc/resolv.conf file and overwriting any modifications made by NetworkManager

interface=$1
action=$2

log() {
logger -i "$0" -t '99-DNSMASQ-RESTART SCRIPT' "$@"
}

# log dns configuration information relevant to SRE while troubleshooting
# The line break used here is important for formatting
log_dns_files() {
log "/etc/resolv.conf contents

$(cat /etc/resolv.conf)"

log "$(echo -n \"/etc/resolv.conf file metadata: \") $(ls -lZ /etc/resolv.conf)"

log "/etc/resolv.conf.dnsmasq contents

$(cat /etc/resolv.conf.dnsmasq)"

log "$(echo -n "/etc/resolv.conf.dnsmasq file metadata: ") $(ls -lZ /etc/resolv.conf.dnsmasq)"
}

if [[ $interface == eth* && $action == "up" ]] || [[ $interface == eth* && $action == "down" ]] || [[ $interface == enP* && $action == "up" ]] || [[ $interface == enP* && $action == "down" ]]; then
log "$action happened on $interface, connection state is now $CONNECTIVITY_STATE"
log "Pre dnsmasq restart file information"
log_dns_files
log "restarting dnsmasq now"
if systemctl try-restart dnsmasq --wait; then
log "dnsmasq successfully restarted"
log "Post dnsmasq restart file information"
log_dns_files
else
log "failed to restart dnsmasq"
fi
fi

exit 0
{{ end }}
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