10 KiB
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:
docker swarm init --advertise-addr <IP_ADDR>
See https://docs.docker.com/engine/swarm/swarm-tutorial/create-swarm/
If you want to add other managers or workers, please use:
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:
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:
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
$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)
$mkdir /mnt/Pool1/pv/mailu
On your manager node, mount the nfs share to check that the share is available:
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:
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 SUBNET.
Let's create the mailu_default network:
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 SUBNET = 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 SUBNET 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 SUBNET 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. As a consequence, we need to use the following work-around:
echo "$(docker-compose -f /mnt/docker/apps/mailu/docker-compose.yml config 2>/dev/null)" | docker stack deploy -c- mailu
We need also to:
- change the way we define the volumes (nfs share in our case)
- add a deploy section for every service
- the way the ports are defined for the front service
Docker compose
An example of docker-compose-stack.yml file is available here:
version: '3.2'
services:
front:
image: mailu/nginx:$VERSION
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:$VERSION
restart: always
env_file: .env
volumes:
# - "$ROOT/mail:/mail"
- type: volume
source: mailu_mail
target: /mail
# - "$ROOT/overrides:/overrides"
- type: volume
source: mailu_overrides
target: /overrides
depends_on:
- front
deploy:
replicas: 2
smtp:
image: mailu/postfix:$VERSION
restart: always
env_file: .env
environment:
- SUBNET=10.0.1.0/24
volumes:
# - "$ROOT/overrides:/overrides"
- type: volume
source: mailu_overrides
target: /overrides
depends_on:
- front
deploy:
replicas: 2
antispam:
image: mailu/rspamd:$VERSION
restart: always
env_file: .env
environment:
- SUBNET=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
# - "$ROOT/overrides/rspamd:/etc/rspamd/override.d"
- type: volume
source: mailu_overrides_rspamd
target: /etc/rspamd/override.d
deploy:
replicas: 1
antivirus:
image: mailu/none:$VERSION
restart: always
env_file: .env
volumes:
# - "$ROOT/filter:/data"
- type: volume
source: mailu_filter
target: /data
deploy:
replicas: 1
webdav:
image: mailu/none:$VERSION
restart: always
env_file: .env
volumes:
# - "$ROOT/dav:/data"
- type: volume
source: mailu_dav
target: /data
deploy:
replicas: 1
admin:
image: mailu/admin:$VERSION
restart: always
env_file: .env
environment:
- SUBNET=10.0.1.0/24
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:$VERSION
restart: always
env_file: .env
volumes:
# - "$ROOT/webmail:/data"
- type: volume
source: mailu_data
target: /data
depends_on:
- imap
deploy:
replicas: 2
fetchmail:
image: mailu/fetchmail:$VERSION
restart: always
env_file: .env
volumes:
deploy:
replicas: 1
networks:
default:
external:
name: mailu_default
volumes:
mailu_filter:
driver_opts:
type: "nfs"
o: "addr=192.168.0.30,soft,rw"
device: ":/mnt/Pool1/pv/mailu/filter"
mailu_dkim:
driver_opts:
type: "nfs"
o: "addr=192.168.0.30,soft,rw"
device: ":/mnt/Pool1/pv/mailu/dkim"
mailu_overrides_rspamd:
driver_opts:
type: "nfs"
o: "addr=192.168.0.30,soft,rw"
device: ":/mnt/Pool1/pv/mailu/overrides/rspamd"
mailu_data:
driver_opts:
type: "nfs"
o: "addr=192.168.0.30,soft,rw"
device: ":/mnt/Pool1/pv/mailu/data"
mailu_mail:
driver_opts:
type: "nfs"
o: "addr=192.168.0.30,soft,rw"
device: ":/mnt/Pool1/pv/mailu/mail"
mailu_overrides:
driver_opts:
type: "nfs"
o: "addr=192.168.0.30,soft,rw"
device: ":/mnt/Pool1/pv/mailu/overrides"
mailu_dav:
driver_opts:
type: "nfs"
o: "addr=192.168.0.30,soft,rw"
device: ":/mnt/Pool1/pv/mailu/dav"
mailu_certs:
driver_opts:
type: "nfs"
o: "addr=192.168.0.30,soft,rw"
device: ":/mnt/Pool1/pv/mailu/certs"
mailu_redis:
driver_opts:
type: "nfs"
o: "addr=192.168.0.30,soft,rw"
device: ":/mnt/Pool1/pv/mailu/redis"
Deploy Mailu on the docker swarm
Run the following command:
echo "$(docker-compose -f /mnt/docker/apps/mailu/docker-compose.yml config 2>/dev/null)" | docker stack deploy -c- mailu
See how the services are being deployed:
core@coreos-01 ~ $ docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
ywnsetmtkb1l mailu_antivirus replicated 1/1 mailu/none:master
pqokiaz0q128 mailu_fetchmail replicated 1/1 mailu/fetchmail:master
check a specific service:
core@coreos-01 ~ $ docker service ps mailu_fetchmail
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
tbu8ppgsdffj mailu_fetchmail.1 mailu/fetchmail:master coreos-01 Running Running 11 days ago
Remove the stack
Run the follwoing command:
core@coreos-01 ~ $ docker stack rm mailu