benschw / coreos-consul-cluster

lightweight docker containers with buildroot

buildroot

docker consul

notes

vagrant up
vagrant ssh node1

fleetctl submit /etc/systemd/system/myapp@.service
fleetctl start myapp@{1..3}

docker run -t -i ubuntu
apt-get install curl dnsutils
dig myapp.service.consul
curl node3.node.dc1.consul:49154/demo

buildroot

curl http://buildroot.uclibc.org/downloads/buildroot-2013.05.tar.bz2 | tar jx
cd buildroot-2013.05/
make menuconfig
# select x86_64
make

cd output/images
mkdir extra extra/etc extra/sbin extra/lib extra/lib64
touch extra/etc/resolv.conf
touch extra/sbin/init
cp /lib/x86_64-linux-gnu/libpthread.so.0 /lib/x86_64-linux-gnu/libc.so.6 extra/lib
cp /lib64/ld-linux-x86-64.so.2 extra/lib64


cp rootfs.tar fixup.tar
tar rvf fixup.tar -C extra .

docker import - dietfs < fixup.tar

systemd

journalctl -f -u hello.service
systemctl status|start|... hello.service

• path: /etc/consul/config.json permissions: 0644 owner: root content: | { "data_dir": "/opt/consul", "client_addr": "0.0.0.0", "ports": { "dns": 53 }, "recursors": ["8.8.8.8"], "disable_update_check": true }

  • name: nameservers.network content: | [Network] DNS=$public_ipv4 #DNS=8.8.8.8

  • name: consul-server.service command: start content: | [Unit] Description=Consul Server Agent Requires=docker.service After=docker.service

    [Service] ExecStartPre=/usr/bin/mkdir -p /opt/bin ExecStartPre=/usr/bin/wget -q https://dl.bintray.com/mitchellh/consul/0.5.0_linux_amd64.zip -O /tmp/consul.zip ExecStartPre=/usr/bin/unzip -o /tmp/consul.zip -d /opt/bin/ ExecStartPre=/usr/bin/chmod +x /opt/bin/consul ExecStartPre=/usr/bin/rm /tmp/consul.zip ExecStart=/bin/bash -c '/opt/bin/consul agent -server -config-dir=/etc/consul/ -advertise $public_ipv4 -bootstrap-expect 3 $(/etc/systems/scripts/consul-join-args)' ExecStartPost=/usr/bin/etcdctl set consul.io/nodes/%m $public_ipv4 ExecReload=/bin/kill -HUP $MAINPID ExecStop=/usr/bin/etcdctl rm consul.io/nodes/%m Restart=on-failure RestartSec=20s

    [Install] WantedBy=multi-user.target

vagrant

if [ ! `which docker` ]; then
  wget -qO- https://get.docker.com/ | sh
  usermod -aG docker vagrant
  BRIDGE=$(ifconfig | grep -A 1 docker | tail -n 1 | awk -F: '{print $2}' | awk '{print $1}')
  echo "DOCKER_OPTS='--dns $BRIDGE --dns 8.8.8.8 --dns-search service.consul'" >> /etc/default/docker
  service docker restart
fi




$provision = <<SCRIPT
# docker ps -q | xargs docker kill
# rm -rf /mnt

BRIDGE=$(ifconfig | grep -A 1 docker | tail -n 1 | awk '{print $2}')
ETH1=$(ifconfig | grep -A 1 eth1 | tail -n 1 | awk '{print $2}')

echo nameserver $BRIDGE > /etc/resolv.conf
echo nameserver $ETH1 >> /etc/resolv.conf

mkdir -p /etc/systemd/resolved.conf.d/
echo [Resolve] > /etc/systemd/resolved.conf.d/consul.conf
echo DNS=$BRIDGE >> /etc/systemd/resolved.conf.d/consul.conf
echo FallbackDNS=8.8.8.8 >> /etc/systemd/resolved.conf.d/consul.conf

systemctl restart systemd-resolved

#-h `hostname` -v /mnt:/data -p $ETH1:8300:8300 -p $ETH1:8301:8301 -p $ETH1:8301:8301/udp -p $ETH1:8302:8302 -p $ETH1:8302:8302/udp -p $ETH1:8400:8400 -p $ETH1:8500:8500 -p $BRIDGE:53:53 -p $BRIDGE:53:53/udp benschw/consul agent -server -config-dir=/config -advertise $ETH1 -data-dir /data -bootstrap-expect 3 -join 172.20.20.10


# EXTRA=""
# if [ `hostname` != "node1" ]; then
#   EXTRA="-join 172.20.20.10"
# fi

# docker run -d -h `hostname` -v /mnt:/data \
#     -p $ETH1:8300:8300 \
#     -p $ETH1:8301:8301 \
#     -p $ETH1:8301:8301/udp \
#     -p $ETH1:8302:8302 \
#     -p $ETH1:8302:8302/udp \
#     -p $ETH1:8400:8400 \
#     -p $ETH1:8500:8500 \
#     -p $BRIDGE:53:53 \
#     -p $BRIDGE:53:53/udp \
#     benschw/consul agent -server -config-dir=/config -advertise $ETH1 -data-dir /data -bootstrap-expect 3 $EXTRA

SCRIPT