6DOS Helps You Explore Your Personal Network
Running in Production
English - February 17, 2020 05:00 - 1 hour - 66.8 MB - ★★★★★ - 8 ratingsTechnology News Tech News deployment elixir flask hosting node rubyonrails phoenix production python techstacks Homepage Download Apple Podcasts Google Podcasts Overcast Castro Pocket Casts RSS feed
Henry Popp goes over building a service with Phoenix and Elixir. It's deployed on GCP with a self managed Kubernetes cluster.
In this episode of Running in Production, Henry Popp goes over building
a platform to help explore your personal network
which was built using Phoenix and Elixir. It’s hosted on Google Cloud using a
self managed Kubernetes cluster. It’s been up and running since September 2019.
Henry went into great detail about the value of using a service oriented
architecture, DDD, event driven design and running a self managed Kubernetes
cluster. There’s a lot of great insights in this episode around general code
design and scaling that apply to any web framework.
Topics Include
2:11 – 4 developers are actively working on the project
2:50 – It’s been running in production since September 2019
3:13 – Motivation for using Phoenix and Elixir
4:26 – Henry started using Elixir back in late 2014
5:48 – Ditching Umbrella apps for dedicated services
7:35 – 6DOS is built on 6 independent git repos with a service oriented architecture
8:20 – A break down of what those 6 repos are and what they do
10:37 – Each service has its own independent database (Postgres, Neo4j, Elasticsearch)
11:21 – Neo4j is a graph database which is a great fit for their main data model
12:55 – How is Elixir support for Neo4j?
13:46 – Each service talks to each other through RabbitMQ events / notifications
15:43 – Walking through the request / response cycle when a visitor hits the site
17:04 – How did you arrive at this service oriented architecture?
18:33 – It’s easy to get Domain-driven Design (DDD) wrong initially
19:42 – Are Phoenix contexts being used? Nope
20:20 – Monoliths vs micro-services vs something in between and industry trends
20:56 – “Instantaneous complexity”
21:39 – Using an app skeleton project to help spin up new services quickly
23:23 – Using VueJS on the front-end with Webpack, but not through Phoenix
24:43 – Currently 6DOS doesn’t need websockets but that could change later
26:47 – Quite a lot of work happens in the background
27:37 – RabbitMQ handles queueing up all of the jobs
29:10 – Docker is being used in production, but not in development (yet)
29:38 – The work flow for starting everything up locally in development
30:52 – Everything is hosted on a self managed Kubernetes cluster on GCP
31:19 – (3) 2 core master nodes, (3) 2 core worker nodes and extra servers for the databases
32:24 – The self managed Kubernetes cluster was terrifying to set up initially
34:00 – Kubernetes is not a magic button you press to scale your application
35:15 – Auto-recovering from a CrashLoopBackOff error with Kubernetes
37:45 – Those 2 CPU core servers have 8 GB of RAM but the app isn’t using all of that
38:47 – Handling an interesting auto-scaling problem with Kubernetes
40:20 – Performing rolling restarts so there’s no down time for each deploy
40:41 – Dealing with restarting containers while an important action is happening
43:23 – Walking through the deploy process from development to production
43:34 – It starts with a self hosted Gitlab instance with automated CI
44:15 – On the other side, Keel takes over to automate deploying any services
45:12 – Helm is being used for a few things, but not everything
46:17 – Humans needing to accept the release happens within Keel’s UI
47:51 – Secrets are stored directly in the self hosted config repo with strict access rights
49:09 – Balancing your time between low level infrastructure vs app features
49:58 – Handling SSL certificates on the cluster with cert-manager
51:06 – Everything is behind a Cloudflare proxy too
51:20 – Dealing with database migrations when you have automated deployments
52:40 – Migrations get run as part of the app boot up process
54:24 – Design your software like a space ship
55:16 – Diagnosing errors with custom tasks and 3rd party tools
56:23 – No one can agree on how to format API JSON errors
57:32 – Elixir best practices are still being discovered, the future is bright
58:19 – An example of one of Henry’s open source Elixir tools (Pigeon) taking off
59:14 – All of the databases get backed up hourly
1:00:26 – Kubernetes really needs to be configured
1:01:16 – Rate limiting is currently being added to all of the services
1:03:07 – What about alerts if something goes down? It’s a digital notification bomb
1:03:36 – Using UptimeRobot as a second sanity check to make sure things are up
1:04:12 – Hung over at 6am out in the middle of the woods and your server goes down
1:04:55 – Using an external tool like UptimeRobot is worth it
1:06:16 – Timber.io is being used for logging but that will change soon
1:07:00 – Kubernetes’ Stern package helps with tailing logs across pods
1:07:44 – Henry isn’t a fan of Kubernetes’ web UI tools to manage the cluster
1:07:54 – Weave Scope was interesting but it used too much resources to run it
1:08:41 – Best tips? Don’t be afraid to break your code up into multiple repos
1:09:45 – If you’re not at that point yet, at least look into using contexts and DDD
1:10:24 – Developers as a whole are getting better over time
1:11:56 – Codedge is Henry’s consulting company and they are on GitHub / Twitter too
Links
📄 References
https://en.wikipedia.org/wiki/Six_degrees_of_separation
https://neo4j.com/developer/cypher-basics-i/
https://en.wikipedia.org/wiki/Directed_acyclic_graph
https://kubernetes.io/docs/concepts/workloads/pods/pod/
https://github.com/keel-hq/keel
https://github.com/jetstack/cert-manager
https://github.com/bitwalker/alpine-elixir
https://github.com/wercker/stern
https://www.weave.works/oss/scope/
⚙️ Tech Stack
phoenix →
elixir →
vue →
cloudflare →
docker →
elasticsearch →
gcp →
gitlab-ci →
grafana →
kubernetes →
neo4j →
postgres →
prometheus →
rabbitmq →
sentry →
stripe →
timber →
uptime-robot →
webpack →
🛠 Libraries Used
https://github.com/florinpatrascu/bolt_sips
https://github.com/bitwalker/distillery
https://github.com/codedge-llc/pigeon
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