Generated a new project since the "official" one used webpack.
Locally, use libcluster and dns_cluster on Fly.io.
To deploy this on Fly.io, a central SQLite is used on a node labelled "PRIMARY_REGION" where every write/read is made.
Project achieved in 7h.
Usage:
PORT=4000 FLY_REGION=ord iex --sname "a" --cookie secret -S mix phx.server
PORT=4001 FLY_REGION=cdg iex --sname "b" --cookie secret -S mix phx.server
...Libcluster with "localEPDM" to cluster the nodes.
An SQLITE DB for persistence with a unique table COUNTER, with two records: region, count.
For the deployment, a primary node is defined where every write/read is made. Done via :erpc.call (could not made liteFS work).
Every change of the GenServer state is saved in the database.
On mount, the socket state is populated by reading the DB and broadcasted to update users view.
On leave, the state is updated
# stop when you have to deploy
fly launch
# remove release_command from fly.toml
fly consul attach
fly deploy#env.sh.eex
ip=$(grep fly-local-6pn /etc/hosts | cut -f 1)
export RELEASE_DISTRIBUTION="name"
export RELEASE_NODE=$FLY_APP_NAME@$ip#Dockerfile - Debian based.
{RUNNER}
apt-get install fuse
RUN apt-get install ca-certificates fuse3...
COPY --from=flyio/litefs:0.5 /usr/local/bin/litefs /usr/local/bin/litefs
COPY litefs.yml /etc/litefs.yml
COPY --from=builder --chown=nobody:root /app/_build/${MIX_ENV}/rel/liveview_counter ./
# USER nobody
ENV ECTO_IPV6 true
ENV ERL_AFLAGS "-proto_dist inet6_tcp"
ENTRYPOINT litefs mountdef start(_type, _args) do
MyApp.Release.migrate()
children = [ {DNSCluster, query: System.get_env("DNS_CLUSTER_QUERY") || :ignore},...]
#config/runtime.exs
config :my_app, dns_cluster_query: System.get_env("DNS_CLUSTER_QUERY")#litejs.yml
fuse:
# This is the mount directory that applications will use to access their SQLite databases.
dir: "/data/mydata"
data:
# path to internal data storage
dir: "/data/litefs"
proxy:
addr: ":8081"
target: "localhost:8080"
# SQLite database filename
db: "my_app_prod.db"
passthrough:
- "*.ico"
- "*.png"
exec:
- cmd: "/app/bin/server -addr :8080 -dsn /data/mydata" <- ??
lease:
type: "consul"
advertise-url: "http://${HOSTNAME}.vm.${FLY_APP_NAME}.internal:20202"
candidate: ${FLY_REGION == PRIMARY_REGION}
promote: true
consul:
url: "${FLY_CONSUL_URL}"
key: "litefs/${FLY_APP_NAME}"#fly.toml
primary_region="cdg"
#[deploy] release_command = "/app/bin/migrate"
[mounts]
source="mydata"
destination="/data"
[env]
PHX_HOST = "my-app.fly.dev"
DNS_CLUSTER_QUERY="my-app.internal"
DATABASE_PATH="/data/mydata/my_app_prod.db"
PORT="8080"> fly ssh console -s -C df
Connecting to fdaa:0:57e6:a7b:aebf:700a:d1cb:2... complete
Filesystem 1K-blocks Used Available Use% Mounted on
devtmpfs 98380 0 98380 0% /dev
/dev/vda 8154588 681300 7037476 9% /
shm 111340 0 111340 0% /dev/shm
tmpfs 111340 0 111340 0% /sys/fs/cgroup
/dev/vdb 1009132 40 940484 1% /data
litefs 1009132 40 940484 1% /data/mydat>fly status
Machines
PROCESS ID VERSION REGION STATE ROLE CHECKS LAST UPDATED
app 1857507c2dd2d8 6 cdg started primary 2023-10-30T10:23:42Z
>fly volumes list
ID STATE NAME SIZE REGION ZONE ENCRYPTED ATTACHED VM CREATED AT
vol_0vdg0y9n18e9lq6v created mydata 1GB cdg 9937 true 1857507c2dd2d8 34 minutes ago
vol_p4m9pjpy6emn7x1v created litefs 1GB cdg c49c true 17 minutes ago
>fly ssh console -s -C df
Filesystem 1K-blocks Used Available Use% Mounted on
devtmpfs 98380 0 98380 0% /dev
/dev/vda 8154588 681364 7037412 9% /
shm 111340 0 111340 0% /dev/shm
tmpfs 111340 0 111340 0% /sys/fs/cgroup
/dev/vdb 997076 40 929044 1% /data
litefs 997076 40 929044 1% /data/mydata
>fly ssh console --pty -C "/app/bin/liveview_counter remote"