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Merged
sshi100 merged 4 commits into from
Sep 29, 2020
Merged

support DNS for VPN client #111

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12af36e
support DNS for VPN client
sshi100 Sep 28, 2020
4e364a6
fix hardcode
sshi100 Sep 28, 2020
2b65ba9
enhancement on display etc.
sshi100 Sep 29, 2020
7c7d2d6
Update add-vpn-user.sh
bmonkman Sep 29, 2020
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4 changes: 2 additions & 2 deletions templates/kubernetes/terraform/modules/kubernetes/files/wireguard-wg0-conf.tpl
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Original file line number Diff line number Diff line change
Expand Up @@ -2,10 +2,10 @@
Address = ${tpl_server_address}
ListenPort = 51820
PostUp = wg set wg0 private-key /etc/wireguard/privatekey
PostUp = iptables -A FORWARD -s ${tpl_server_address} -d ${tpl_destination_subnets} -j ACCEPT
PostUp = iptables -A FORWARD -i wg0 -s ${tpl_server_address} -j ACCEPT
PostUp = iptables -A FORWARD -s ${tpl_server_address} -j DROP
PostUp = iptables -t nat -A POSTROUTING -s ${tpl_server_address} -o eth0 -j MASQUERADE
PostDown = iptables -D FORWARD -s ${tpl_server_address} -d ${tpl_destination_subnets} -j ACCEPT
PostDown = iptables -D FORWARD -i wg0 -s ${tpl_server_address} -j ACCEPT
PostDown = iptables -D FORWARD -s ${tpl_server_address} -j DROP
PostDown = iptables -t nat -D POSTROUTING -s ${tpl_server_address} -o eth0 -j MASQUERADE

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52 changes: 37 additions & 15 deletions templates/scripts/add-vpn-user.sh
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Expand Up @@ -4,56 +4,77 @@ CLUSTER=$(kubectl config current-context | cut -d"/" -f2)

# this is a local script for a system user to generate VPN configuration for cluster ${CLUSTER}

NAMESPACE=<% .Name %>
REGION=<% index .Params `region` %>

# get pod id for execution
POD=$(kubectl -n vpn get pods | grep wireguard | cut -d' ' -f1)
EXTERNAL_DNS=$(kubectl -nvpn get svc wireguard -o jsonpath='{.metadata.annotations.external-dns\.alpha\.kubernetes\.io/hostname}')
POD=$(kubectl -n vpn get pods --selector=app=wireguard -o jsonpath='{.items[0].metadata.name}')

if [ -z "$POD" ]; then
echo "Warning: No VPN service running yet"
exit 1
fi
EXEC="kubectl -n vpn exec -it $POD -- /bin/bash -c"

function k8s_exec() {
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@bmonkman bmonkman Sep 29, 2020

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👍

kubectl -n vpn exec -it $POD -- /bin/bash -c "$1"
}

# get name
echo -n "Enter your name: "
read name
echo "Current cluster is '${CLUSTER}'"
echo -n "Enter your name: " && read name
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@bmonkman bmonkman Sep 28, 2020

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Let's print the name of the cluster before this so they know which context they are using. Otherwise they don't really know where they are adding the user to, and I don't think we explicitly tell them to change their kube context.

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@sshi100 sshi100 Sep 29, 2020

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done

echo
echo "Generating your client configuration file..."

# collect keys
server_public_key=$($EXEC "cat /etc/wireguard/privatekey | wg pubkey")
client_private_key=$($EXEC "wg genkey")
client_public_key=$($EXEC "echo -n $client_private_key | wg pubkey | tr -d \"\r\n\f\"")
server_public_key=$(k8s_exec "cat /etc/wireguard/privatekey | wg pubkey")
client_private_key=$(k8s_exec "wg genkey")
client_public_key=$(k8s_exec "echo -n $client_private_key | wg pubkey | tr -d \"\r\n\f\"")

# get next available IP
existing_ips=$($EXEC "cat /etc/wireguard/wg0.conf | grep AllowedIPs| cut -d\" \" -f3 | cut -d\"/\" -f1 | sort")
existing_ips=$(k8s_exec "cat /etc/wireguard/wg0.conf | grep AllowedIPs| cut -d\" \" -f3 | cut -d\"/\" -f1 | sort")
last_ip=$(echo "$existing_ips" | tr -cd "[:alnum:].\n" | tail -1)
next_ip=$last_ip
while [[ "$existing_ips" =~ "$next_ip" ]]; do
next_ip=${next_ip%.*}.$((${next_ip##*.}+1))
done

# get DNS server setting
dns_server=$(k8s_exec "cat /etc/resolv.conf | grep nameserver | tail -1 | cut -d\" \" -f2 | tr -d \"\r\n\f\"")

# get VPC CIDR for allowed IP subnet
VPCNAME=${CLUSTER%-$REGION}-vpc
vpc_cidr=$(aws ec2 describe-vpcs --filters Name=tag:Name,Values=${VPCNAME} | jq -r '.Vpcs[].CidrBlock')
[[ -z "$vpc_cidr" ]] && vpc_cidr = "10.10.0.0/16"

# get Endpoint DNS
EXTERNAL_DNS=$(kubectl -nvpn get svc wireguard -o jsonpath='{.metadata.annotations.external-dns\.alpha\.kubernetes\.io/hostname}')

# generate config file
CONFIG_DIR=~/.wireguard
mkdir -p $CONFIG_DIR
CONFIG_FILE=$CONFIG_DIR/wg-client-${CLUSTER}.conf

# Output TF line
echo "Configuration generated at $CONFIG_FILE with:"
echo
echo "Configuration for user '$name' generated at $CONFIG_FILE with:"
echo " - public key : $client_public_key"
echo " - private key: $client_private_key"
echo " - client IP : $next_ip/32"
echo
echo "Please modify kubernetes/terraform/environments/<env>/main.tf and append the following line to var.vpn_client_publickeys."
echo "Then apply the terraform, or ask an administrator to."
echo
printf ' ["%s", "%s", "%s"],' "$name" "$next_ip/32" "$client_public_key"
printf ' ["%s", "%s", "%s"],\n' "$name" "$next_ip/32" "$client_public_key"
echo
echo "After this is done you should be able to open the wireguard client and activate the tunnel."
echo "You can download the client at https://www.wireguard.com/install/"
echo "After this is done you should be able to open the wireguard client, import a tunnel file from ~/.wireguard/ and activate the tunnel."
echo
echo "When it is running you should be able to access internal resources, e.g. mysql -h 10.10.10.123"
echo "When it is running you should be able to access internal resources, eg. mysql -h <aws rds hostname>"
echo "You will be able to connect to resources within both the VPC and the Kubernetes cluster."
echo

# generate client conf
cat <<-EOF > ${CONFIG_FILE}

#
# This is a generated VPN(wireguard) client configuration
#
Expand All @@ -65,11 +86,12 @@ cat <<-EOF > ${CONFIG_FILE}
PrivateKey = $client_private_key
ListenPort = 34567
Address = $next_ip/32
DNS = $dns_server

[Peer]
# VPN server side
PublicKey = $server_public_key
AllowedIPs = 10.10.0.0/16
AllowedIPs = $vpc_cidr, $dns_server/32
Endpoint = $EXTERNAL_DNS:51820

EOF
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