Deploy a resilient three-tier app

The 10 steps and what each one checks

Every step ends with a validation pass that inspects your actual containers. The lines below are the exact observations it makes. The instructions, hints and commented walkthroughs live in the app.

1. step 1 of 10

   Your first server

   • check: container "web-1" is running

2. step 2 of 10

   The data tier

   • check: container "db" is running
   • check: table "users" exists in "db"

3. step 3 of 10

   Wire the app to its database

   • check: web-1 → db is reachable on :5432

4. step 4 of 10

   Ship the bookstore

   • check: GET :80/ on "web-1" contains "Nimbus Books"
   • check: GET :80/ on "web-1" contains "ada@nimbus.dev"

5. step 5 of 10

   Two of everything

   • check: container "web-2" is running
   • check: GET :80/ on "web-2" contains "Nimbus Books"
   • check: GET :80/ on "web-2" contains "ada@nimbus.dev"

6. step 6 of 10

   One front door

   • check: "lb" is balancing across ≥ 2 upstreams
   • check: GET :80/ on "lb" contains "Nimbus Books"

7. step 7 of 10

   Lock the vault

   • check: lb → db is blocked on :5432
   • check: web-1 → db is reachable on :5432
   • check: web-2 → db is reachable on :5432

8. step 8 of 10

   Pull the plug

   • check: GET :80/ on "lb" contains "Nimbus Books"

9. step 9 of 10

   The clone factory

   • check: "web-asg" keeps 2 replicas running
   • check: container "web-1" is running

10. step 10 of 10

    Launch day

    • check: "web-asg" keeps 4 replicas running
    • check: "lb" is balancing across ≥ 4 upstreams
    • check: GET :80/ on "lb" contains "Nimbus Books"