docker-etcd-registrator

Docker service registrator for etcd (and CoreOS). The very end of sidekick.service

• SkyDNS support
• Vulcanproxy support
• Startup synchronization: bring etcd up to date
• Add already running containers
• Remove stopped but registred container
• Realtime: Listening for docker events
• Registers all ports
• defined via EXPOSE in the Dockerfile
• exposed via -p commandline argument
• Supports secured etcd
• Service config using ENV
• Written in Javascript
• for (but not limited to) CoreOS, see fleet-unit-files

(thanks to gliderlabs/registrator for the some ideas)

TODO / Planned

• Configuration using commandline arguments
• Improve docu

Install & Config

• You need NodeJS >= 0.12.x and NPM; Should also run with IO.JS
• For now its only possible to configure docker-etcd-registrator using environment variables
• Make sure the app can read/write to DOCKER_HOST (default: /var/run/docker.sock)

sudo npm install -g docker-etcd-registrator
 
DEBUG=docker,skydns,service \
  ETCD_ENDPOINTS=http://10.1.0.1:4001,http://10.1.0.2:4001 \
  docker-etcd-registrator

Docker

docker run --rm \
  --name docker-etcd-registrator \
  -v /etc/ssl/etcd:/etc/ssl/etcd \
  -v /var/run/docker.sock:/var/run/docker.sock \
  --env DEBUG=docker,skydns,vulcand,container \
  --env HOSTNAME=`hostname` \
  --env ETCD_ENDPOINTS=https://10.1.0.1:4001,https://10.1.0.2:4001 \
  --env ETCD_CAFILE=/etc/ssl/etcd/ca-authority.pem \
  --env ETCD_CERTFILE=/etc/ssl/etcd/certificate.crt \
  --env ETCD_KEYFILE=/etc/ssl/etcd/key.key \
  psitrax/docker-etcd-registrator

Manual:

git clone https://github.com/psi-4ward/docker-etcd-registrator.git
cd docker-etcd-registrator
npm install
ETCD_ENDPOINTS=http://10.1.0.1:4001 node app.js

Config parameters

All params are optional

• HOSTNAME: Hostname of the system
• REGISTER=public: Register only Ports which binds to the host interface (docker -p)
• REGISTER_PUBLIC_IP=10.0.1.1: IP if Hostbinding dont specify any (docker -p 80:80 instead of docker -p 10.0.1.1:80:80)
• SKYDNS_ETCD_PREFIX: /skydns/local/skydns
• VULCAND_ETCD_PREFIX: /skydns/local/skydns
  
• DOCKER_HOST: /var/run/docker.sock or tcp://localhost:2376
• DOCKER_TLS_VERIFY from docker-modem
• DOCKER_CERT_PATH: Directory containing ca.pem, cert.pem, key.pem (filenames hardcoded)
  
• ETCD_ENDPOINTS: http://127.0.0.1:4001
• ETCD_CAFILE
• ETCD_CERTFILE
• ETCD_KEYFILE

Debug

Enable debugging using DEBUG env var: DEBUG=docker,skydns,service node app.js

flag	description
*	print every debug message
docker	docker related messages
conteiner	container-inspect => service transformation
skydns	skydns etcd data population
vulcand	skydns etcd data population
modem	raw docker socket messages

Service Discovery Configration

• Use env vars to configure a specific container / service
• Everything is optional
• Name is received from SERVICE_NAME or --name or the container ID
• Services with SERVICE_IGNORE are not observed

$ docker run -d --name mariadb \
    -e "SERVICE_NAME=mysql" \
    -e "SERVICE_TAGS=database,customers" \
    mariadb

Multiple Services per Container

You can specify a service identified by a given port SERVICE_<PORT>_<FLAG>:

$ docker run -p 80:80 -p 443:443 -p 9000:9000 \
    -e "SERVICE_80_NAME=http-proxy" \
    -e "SERVICE_443_NAME=https-proxy" \
    -e "SERVICE_9000_IGNORE=yes" \
    docker/image

Vulcand

Use SERVICE_[PORT_]VULCAND_(BE|FE)_ formatted env vars to generate etcd values for Vulcanproxy. Per default registrator will not generate any vulcand frontend or backend.

In general the SERVICE_VULCAND_FE_k1_k2_k3=value style would result in a JSON structure like: {"k1": {"k2": {"k3": "value"} } }

Generate a vulcand-backend of type http using the defaults for every port but 9000:

$ docker run -p 80:80 -p 443:443 -p 9000:9000 \
    -e "SERVICE_NAME=websrv" \
    -e "SERVICE_VULCAND_BE_Type=http" \
    -e "SERVICE_9000_IGNORE=yes" \
    docker/image

Defining more FE/BE settings

$ docker run -p 3000:3000 -p 22:22 \
    -e "SERVICE_22_IGNORE=yes" \
    -e "SERVICE_3000_NAME=microservice" \
    -e "SERVICE_3000_VULCAND_BE_Type=http" \
    -e "SERVICE_3000_VULCAND_BE_Settings_Timeouts_Read=10s" \
    -e "SERVICE_3000_VULCAND_BE_Settings_KeepAlive_MaxIdleConnsPerHost=20" \
    -e "SERVICE_3000_VULCAND_FE_Type=https" \
    -e "SERVICE_3000_VULCAND_FE_Route=Host('ms.example.com')" \
    -e "SERVICE_3000_VULCAND_FE_Settings_Limits_MaxBodyBytes=4048" \
    docker/image

Authors

• Christoph Wiechert

License

MIT