Temporal Fly.io

README.md

Since there were a few people asking how to setup Temporal on Fly.io, I'd thought this would be useful.

Disclaimer: I'm not a Fly nor Temporal expert (in fact I'm a big noob) so you'll have to forgive me. Any suggestions are welcome to improve these configs for others and myself.

Don't forget to add a private ip6 address: fly ips allocate-v6 --private

This is required for the ui app to connect to the server via .flycast

Dockerfile

ARG GOPROXY

##### Temporal server with Auto-Setup #####
FROM temporalio/ui:2.27.2 as ui
FROM temporalio/server:1.24.1.0 as server

WORKDIR /etc/temporal

FROM temporalio/auto-setup:1.24.1.0 as final

COPY --from=ui --chown=temporal:temporal /home/ui-server /home/ui-server
RUN rm -rf /home/ui-server/config/*

EXPOSE 7233 8080

# Use Mysql, ES, or something else
ENV DB=postgres12
ENV DB_PORT=5432 

# Move these to `fly secrets`
ENV POSTGRES_SEEDS=db.xxx.supabase.co (or w/e your db domain is)
ENV POSTGRES_USER=postgres
ENV POSTGRES_PWD=P@ssw0rd (use a better password)
ENV DBNAME=postgres
# Change Visibility to a different table. I'm using the same one at the moment b/c supabase's free tier only allows
# for 1 free table. This requires manual migration.
ENV VISIBILITY_DBNAME=postgres

ENV BIND_ON_IP=0.0.0.0
ENV TEMPORAL_BROADCAST_ADDRESS=0.0.0.0
ENV DEFAULT_NAMESPACE=default

ENV DYNAMIC_CONFIG_FILE_PATH=/etc/temporal/config/dynamicconfig/docker.yaml

# These two .sh files are defined below
COPY ./start.sh /etc/temporal/start.sh
COPY ./start-ui.sh /etc/temporal/start-ui.sh
CMD ["autosetup"]

ENTRYPOINT ["/etc/temporal/start.sh"]

fly.toml

app = 'my-temporal-app'
primary_region = 'sea'


[processes]
  server = '/etc/temporal/entrypoint.sh autosetup'
  ui = '/etc/temporal/start-ui.sh'


[[services]]
  protocol = 'tcp'
  internal_port = 7233
  auto_stop_machines = true
  auto_start_machines = true
  min_machines_running = 1
  processes = ['server']

  [[services.ports]]
    port = 7233
    # handlers = ['http'] # Do not expose to public, public ipv4/6 should be removed already
    # alpn h2 is needed for the grpc protocol
    [services.ports.tls_options]
      alpn = ['h2']

  [[services.tcp_checks]]
    interval = '10s'
    timeout = '2s'
    grace_period = '5s'

[[services]]
  protocol = 'tcp'
  internal_port = 8080
  auto_stop_machines = true
  auto_start_machines = true
  min_machines_running = 0
  processes = ['ui']

  # Ideally, don't expose the UI to the public, keep it behind a CDN (eg Cloudflare) and whitelist the IP
  # or make it public but set up SSO
  [[services.ports]]
    port = 8080
    # handlers = ['http']

  # [[services.ports]]
  #   port = 443
  #   handlers = ['tls', 'http']

[[vm]]
  size = 'shared-cpu-1x'

start-ui.sh

#!/bin/sh

# The Temporal UI Server expects the script to be executed at the `/home/ui-server`
cd /home/ui-server
# Assuming your server/ui is running in the same Fly app (but different process)
# Change this to another fly app or IP if running elsewhere.
export TEMPORAL_ADDRESS="${FLY_APP_NAME}.flycast:7233"
./start-ui-server.sh

start.sh

#!/bin/sh

# This is called via the fly.toml:
# [processes]
#  server = "/etc/temporal/entrypoint.sh autosetup"
#  ui = "/etc/temporal/start-ui.sh"
#
# This script itself is called in the Dockerfile:
# ENTRYPOINT ["/etc/temporal/start.sh"]
exec "$@"

That looks good now. Your server should be running 24/7 (you may want to process.exit(0) after your worker finishes and use the machine API to wake it up to save money).
The ui apps will auto shutdown, which is what has excess capacity, autostopping machine is saying.

The healthchecks are good now right? I see the green dot.

Thank you! The ui machines went to sleep, but there is only one server machine and it still shows 0/1 healthchecks passing for some reason (3rd column in the image above). Wondering if I should try to re-deploy this app again...

Is creating private IP a manual step that needs to be done after each new deployment? This is my first time working with Fly.io.

When you launch a new app you can pass --flycast for it to automatically assign the private ip6. Once an app is launched, you don't need to create ips on deploy or scaling up.
Regarding the failed health check, you'll need to filter by the server process to see what the error is. I'm guessing it's DB related.

I've tried --flycast option with fly launch, but nothing happened. I had to move it to fly deploy for the IP address to be assigned. Still getting health check error. I'll be working on figuring out how to filter by the server process like you mentioned, because there is not much useful info in the log that could point to the source of error.

This is how I currently launch this app. Maybe you'll see anything missing. Thank you very much again. You've been a tremendous help.

1. Create app in Fly.io

   fly launch --config apps/worker/fly.dev.toml --dockerfile Dockerfile.remote --build-only
   ---
   ? Would you like to copy its configuration to the new app? Yes
   ? Do you want to tweak these settings before proceeding? No

2. Set secrets

   # In Fish
   bash -c 'fly secrets set --config apps/worker/fly.dev.toml \
     DATABASE_URL=postgres://postgres:[db-password]@[db-app-name].internal:5432 \
     POSTGRES_USER=postgres \
     POSTGRES_PASSWORD=[db-password]'

3. Deploy app to Fly.io

   fly deploy --config apps/worker/fly.dev.toml --flycast

For step 2, I don't think those are the correct env variables for temporal. It should be:

ENV POSTGRES_SEEDS=db.xxx.supabase.co (or w/e your db domain is)
ENV POSTGRES_USER=postgres
ENV POSTGRES_PWD=P@ssw0rd (use a better password)
ENV DBNAME=postgres
ENV VISIBILITY_DBNAME=postgres // change this to a different table.

There isn't DATABASE_URL, and that should only contain [db-app-name].flycast:5432

For step 3, you don't need to pass in --flycast. You only need to set that up when you launch your app for the first time.

For step 3, you don't need to pass in --flycast. You only need to set that up when you launch your app for the first time.

For me it works only when I add --flycast flag to fly deploy. Maybe because my fly launch uses the --build-only flag?

Regarding the failed health check, you'll need to filter by the server process to see what the error is. I'm guessing it's DB related.

Where would I find the log that would allow me to see the DB connection errors? When I do fly logs -a [app-name] I only see the error related to the failed health check, nothing more on what could actually cause this check to fail.

you should be able to see the entire logs. If you're not seeing anything useful, try adding TEMPORAL_DEBUG=true to your env variable.
I'm not sure what the actual flag is so that might be wrong.
EDIT: LOG_LEVEL = 'debug'

Just in case this helps others. Adding TEMPORAL_DEBUG=true env var didn't make any difference, but LOG_LEVEL = 'debug' (in fly.toml) made debug level messages show up. I've also had to comment out ENV VISIBILITY_DBNAME=postgres, so default temporal_visibility database is created. Without it, I was missing some visibility tables in the postgres DB.

I have successfully started the server app (@khuezy you rock!). I've verified that the schema got provisioned in DB too. Just trying to figure out how to access UI at this point. I've assigned public IP to the app, but nothing comes up. I am sure it's me missing something. This is what I get:

# Verify public IP assigned
$ dig +short [app-name].fly.dev
137.x.x.x

# Try to access the app
$ curl -Iv https://[app-name].fly.dev
* Could not resolve host: [app-name].fly.dev
* Closing connection
curl: (6) Could not resolve host: [app-name].fly.dev

Nice! Glad you got the server figured out. For the UI... the example above intentionally does not expose the ui app publicly, as that would be a bad idea. What you should do is create an nginx app that proxies to the ui app via .flycast via server name, eg tempralui.example.com.
Then the entry point to that address would be via CDN (Cloudflare) protected by IP whitelist. Or you can basic-auth protect it directly in your nginx config.

Got it! Yes, I've gone through your fly.toml and noticed those commented out lines. Once I've enabled these, the UI started to show up:

[[services.ports]]
    port = 80
    handlers = ['http']

[[services.ports]]
  port = 443
  handlers = ['tls', 'http']

I am going to comment out these lines again per your advice. I agree this UI should be protected for authorized access only.

Also, an alternative and much easier way to access UI is just forward remote port to localhost.

1. Forward port in a separate terminal

   fly proxy 8080 -a [temporal-server-app-name]

2. Access UI at http://localhost:8080/

👍 Yup that's the simplest way if you don't need remote access.