# Install Mailu on a docker swarm ## Prequisites ### Swarm In order to deploy Mailu on a swarm, you will first need to initialize the swarm: The main command will be: ```bash docker swarm init --advertise-addr ``` See https://docs.docker.com/engine/swarm/swarm-tutorial/create-swarm/ If you want to add other managers or workers, please use: ```bash docker swarm join --token xxxxx ``` See https://docs.docker.com/engine/swarm/join-nodes/ You have now a working swarm, and you can check its status with: ```bash core@coreos-01 ~/git/Mailu/docs/swarm/1.5 $ docker node ls ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS ENGINE VERSION xhgeekkrlttpmtgmapt5hyxrb black-pearl Ready Active 18.06.0-ce sczlqjgfhehsfdjhfhhph1nvb * coreos-01 Ready Active Leader 18.03.1-ce mzrm9nbdggsfz4sgq6dhs5i6n flying-dutchman Ready Active 18.06.0-ce ``` ### Volume definition For data persistance (the Mailu services might be launched/relaunched on any of the swarm nodes), we need to have Mailu data stored in a manner accessible by every manager or worker in the swarm. Hereafter we will use a NFS share: ```bash core@coreos-01 ~ $ showmount -e 192.168.0.30 Export list for 192.168.0.30: /mnt/Pool1/pv 192.168.0.0 ``` on the nfs server, I am using the following /etc/exports ```bash $more /etc/exports /mnt/Pool1/pv -alldirs -mapall=root -network 192.168.0.0 -mask 255.255.255.0 ``` on the nfs server, I created the Mailu directory (in fact I copied a working Mailu set-up) ```bash $mkdir /mnt/Pool1/pv/mailu ``` On your manager node, mount the nfs share to check that the share is available: ```bash core@coreos-01 ~ $ sudo mount -t nfs 192.168.0.30:/mnt/Pool1/pv/mailu /mnt/local/ ``` If this is ok, you can umount it: ```bash core@coreos-01 ~ $ sudo umount /mnt/local/ ``` ### Networking mode On this example, we are using: - the mesh routing mode (default mode). With this mode, each service is given a virtual IP adress and docker manages the routing between this virtual IP and the container(s) providing this service. - the default ingress mode. ## Allow authentification with the mesh routing In order to allow every (front & webmail) container to access the other services, we will use the variable POD_ADDRESS_RANGE. Let's create the mailu_default network: ```bash core@coreos-01 ~ $ docker network create -d overlay --attachable mailu_default core@coreos-01 ~ $ docker network inspect mailu_default | grep Subnet "Subnet": "10.0.1.0/24", ``` In the docker-compose.yml file, we will then use POD_ADDRESS_RANGE = 10.0.1.0/24 In fact, imap & smtp logs doesn't show the IPs from the front(s) container(s), but the IP of "mailu_default-endpoint". So it is sufficient to set POD_ADDRESS_RANGE to this specific ip (which can be found by inspecting mailu_default network). The issue is that this endpoint is created while the stack is created, I did'nt figure a way to determine this IP before the stack creation... ## Limitation with the ingress mode With the default ingress mode, the front(s) container(s) will see origin IP(s) all being 10.255.0.x (which is the ingress-endpoint, can be found by inspecting the ingress network) This issue is known and discussed here: https://github.com/moby/moby/issues/25526 A workaround (using network host mode and global deployment) is discussed here: https://github.com/moby/moby/issues/25526#issuecomment-336363408 ## Don't create an open relay ! As a side effect of this ingress mode "feature", make sure that the ingress subnet is not in your RELAYHOST, otherwise you would create an smtp open relay :-( ### Scalability - smtp and imap are scalable - front and webmail are scalable (pending POD_ADDRESS_RANGE is used), although the let's encrypt magic might not like it (race condidtion ? or risk to be banned by let's encrypt server if too many front containers attemps to renew the certs at the same time) - redis, antispam, antivirus, fetchmail, admin, webdav have not been tested (hence replicas=1 in the following docker-compose.yml file) ### Variable substitution and docker-compose.yml The docker stack deploy command doesn't support variable substitution in the .yml file itself (but we still can use .env file to pass variables to the services). As a consequence we need to adjust the docker-compose file in order to : - remove all variables : $VERSION , $BIND_ADDRESS4 , $BIND_ADDRESS6 , $ANTIVIRUS , $WEBMAIL , etc - change the way we define the volumes (nfs share in our case) - add a deploy section for every service ### Docker compose An example of docker-compose-stack.yml file is available here: ```yaml version: '3.2' services: front: image: mailu/nginx:master restart: always env_file: .env ports: - target: 80 published: 80 - target: 443 published: 443 - target: 110 published: 110 - target: 143 published: 143 - target: 993 published: 993 - target: 995 published: 995 - target: 25 published: 25 - target: 465 published: 465 - target: 587 published: 587 volumes: # - "$ROOT/certs:/certs" - type: volume source: mailu_certs target: /certs deploy: replicas: 2 redis: image: redis:alpine restart: always volumes: # - "$ROOT/redis:/data" - type: volume source: mailu_redis target: /data deploy: replicas: 1 imap: image: mailu/dovecot:master restart: always env_file: .env environment: - POD_ADDRESS_RANGE=10.0.1.0/24 volumes: # - "$ROOT/data:/data" - type: volume source: mailu_data target: /data # - "$ROOT/mail:/mail" - type: volume source: mailu_mail target: /mail # - "$ROOT/overrides:/overrides" - type: volume source: mailu_overrides target: /overrides depends_on: - front deploy: replicas: 2 smtp: image: mailu/postfix:master restart: always env_file: .env environment: - POD_ADDRESS_RANGE=10.0.1.0/24 volumes: # - "$ROOT/data:/data" - type: volume source: mailu_data target: /data # - "$ROOT/overrides:/overrides" - type: volume source: mailu_overrides target: /overrides depends_on: - front deploy: replicas: 2 antispam: image: mailu/rspamd:master restart: always env_file: .env environment: - POD_ADDRESS_RANGE=10.0.1.0/24 depends_on: - front volumes: # - "$ROOT/filter:/var/lib/rspamd" - type: volume source: mailu_filter target: /var/lib/rspamd # - "$ROOT/dkim:/dkim" - type: volume source: mailu_dkim target: /dkim # - "$ROOT/overrides/rspamd:/etc/rspamd/override.d" - type: volume source: mailu_overrides_rspamd target: /etc/rspamd/override.d deploy: replicas: 1 antivirus: image: mailu/none:master restart: always env_file: .env volumes: # - "$ROOT/filter:/data" - type: volume source: mailu_filter target: /data deploy: replicas: 1 webdav: image: mailu/none:master restart: always env_file: .env volumes: # - "$ROOT/dav:/data" - type: volume source: mailu_dav target: /data deploy: replicas: 1 admin: image: mailu/admin:master restart: always env_file: .env volumes: # - "$ROOT/data:/data" - type: volume source: mailu_data target: /data # - "$ROOT/dkim:/dkim" - type: volume source: mailu_dkim target: /dkim - /var/run/docker.sock:/var/run/docker.sock:ro depends_on: - redis deploy: replicas: 1 webmail: image: "mailu/roundcube:master" restart: always env_file: .env volumes: # - "$ROOT/webmail:/data" - type: volume source: mailu_data target: /data depends_on: - imap deploy: replicas: 2 fetchmail: image: mailu/fetchmail:master restart: always env_file: .env volumes: # - "$ROOT/data:/data" - type: volume source: mailu_data target: /data deploy: replicas: 1 networks: default: external: name: mailu_default volumes: mailu_filter: driver_opts: type: "nfs" o: "addr=192.168.0.30,nolock,soft,rw" device: ":/mnt/Pool1/pv/mailu/filter" mailu_dkim: driver_opts: type: "nfs" o: "addr=192.168.0.30,nolock,soft,rw" device: ":/mnt/Pool1/pv/mailu/dkim" mailu_overrides_rspamd: driver_opts: type: "nfs" o: "addr=192.168.0.30,nolock,soft,rw" device: ":/mnt/Pool1/pv/mailu/overrides/rspamd" mailu_data: driver_opts: type: "nfs" o: "addr=192.168.0.30,nolock,soft,rw" device: ":/mnt/Pool1/pv/mailu/data" mailu_mail: driver_opts: type: "nfs" o: "addr=192.168.0.30,nolock,soft,rw" device: ":/mnt/Pool1/pv/mailu/mail" mailu_overrides: driver_opts: type: "nfs" o: "addr=192.168.0.30,nolock,soft,rw" device: ":/mnt/Pool1/pv/mailu/overrides" mailu_dav: driver_opts: type: "nfs" o: "addr=192.168.0.30,nolock,soft,rw" device: ":/mnt/Pool1/pv/mailu/dav" mailu_certs: driver_opts: type: "nfs" o: "addr=192.168.0.30,nolock,soft,rw" device: ":/mnt/Pool1/pv/mailu/certs" mailu_redis: driver_opts: type: "nfs" o: "addr=192.168.0.30,nolock,soft,rw" device: ":/mnt/Pool1/pv/mailu/redis" ``` ### Deploy Mailu on the docker swarm Run the following command: ```bash docker stack deploy -c docker-compose-stack.yml mailu ``` See how the services are being deployed: ```bash core@coreos-01 ~ $ docker service ls ID NAME MODE REPLICAS IMAGE PORTS ywnsetmtkb1l mailu_antivirus replicated 1/1 mailu/none:1.5 pqokiaz0q128 mailu_fetchmail replicated 1/1 mailu/fetchmail:1.5 ``` check a specific service: ```bash core@coreos-01 ~ $ docker service ps mailu_fetchmail ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS tbu8ppgsdffj mailu_fetchmail.1 mailu/fetchmail:1.5 coreos-01 Running Running 11 days ago ``` ### Remove the stack Run the follwoing command: ```bash core@coreos-01 ~ $ docker stack rm mailu ```