https://github.com/jsilvela/kubecon-webapp-cnpg
Support code for a Virtual Office Hours demo given at the 2022 Kubecon Valencia
https://github.com/jsilvela/kubecon-webapp-cnpg
kubernetes operator postgresql
Last synced: about 2 months ago
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Support code for a Virtual Office Hours demo given at the 2022 Kubecon Valencia
- Host: GitHub
- URL: https://github.com/jsilvela/kubecon-webapp-cnpg
- Owner: jsilvela
- Created: 2022-05-09T07:08:08.000Z (about 4 years ago)
- Default Branch: main
- Last Pushed: 2022-05-23T06:42:23.000Z (about 4 years ago)
- Last Synced: 2025-06-04T05:04:24.878Z (about 1 year ago)
- Topics: kubernetes, operator, postgresql
- Language: Go
- Homepage:
- Size: 30.3 KB
- Stars: 2
- Watchers: 1
- Forks: 2
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Webapp development with CloudNativePG
This repo has support code for a Virtual Office Hours demo given at the
2022 Kubecon Valencia, on 2022-05-18 by me (Jaime).
Contains:
- Liquibase config and initial migration
- Webapp in Go
- Makefile and cheat-sheet (to aid this poor typist)
- Dockerfile and K8s YAML's for the webapp
Assumed to be installed on demo machine:
- KinD cluster
- CloudNativePG operator
- Liquibase
Uses the `cluster-example.yaml` sample in `docs/src/samples`.
## Summary
The purpose of the demo is to show CloudNativePG is a great tool to develop
web applications on dev machines, and opens up possibilities to do all sorts of
things before putting in prod.
We try to show a viable workflow using Liquibase for schema migrations,
and a webapp written in Go using only the standard
`net/http`, `database/sql` and `lib/pq` packages.
Two halves to the demo:
1. "Average" or "old-style" approach: postgres installed locally, possibly even
dockerized. Webapp developed locally, executed natively or dockerized.
We ape this by installing a 1-pod cluster using the `cluster-example.yaml` sample
with 1 replica instead of 3.
We run the webapp outside of KinD and hit `localhost:5432` from it.
2. Better way: we dockerize the webapp, push to the KinD nodes, create a
deployment and a service for it. We hit the `cluster-example-rw` service.
We show the possibilities that open up.
## Demo and slides
### Slide: Using CloudNativePG from outside Kubernetes
Show diagram for "Case 2" from the
[cnpg docs](https://cloudnative-pg.io/documentation/1.15.0/use_cases/)
### Slide: "The Old Way", but using CloudNativePG
#### Ingredient list
1. Basic web application written in Go (aka golang)
1. Kubernetes cluster (in this case KinD running on macOS)
1. The CloudNativePG operator installed on KinD
1. Schema migration tool: Liquibase
#### game plan
1. Create the simplest CloudNativePG cluster
1. Start with an empty PostgreSQL DB
1. Get DB connection credentials
1. Apply migrations with Liquibase - comment on Postgres's **Transactional DDL**
1. Add port forwarding to expose DB (necessary if running KinD on macOS)
1. Start the webapp natively
### Slide: Putting your webapp inside Kubernetes
Show first diagram for "Case 1" from the
[cnpg docs](https://cloudnative-pg.io/documentation/1.15.0/use_cases/)
Take opportunity to show the web page for cnpg and the documentation link.
### Slide: Leveraging CloudNativePG - cooking with fire
#### Ingredient list
1. Let’s Dockerize our webapp and load it into our KinD cluster
1. Make a deployment and a loadBalancer for our webapp
1. The webapp should now hit the -rw (cluster-example-rw) Service
#### game plan
1. Let’s scale our CloudNativePG cluster to 3 instances
1. Close the running webapp
1. Deploy the webapp (show Dockerfile and K8s YAML while cluster scales up)
1. Let’s add a watch on the cluster. Let’s put some load on it
1. Let’s kill the primary!!
1. (with enough time) - Have a look around in the `cloudnative-pg` repo
## Slide: Reflections and questions
Talk about how once we start leveraging CloudNativePG, we enable developers
to do experiments that require DBA skills. And we allow them to develop locally
with a DB much more similar to what production will look like.
When they deal with prod issues on their app, those developers will have gained
hands-on experience already.
And bridging the gap between dev and prod is one of the tenets of the DevOps
movement.