basic-redis-leaderboard-demo-go

Basic Redis Leaderboard Demo Golang

Show how the Redis works with Golang.

How it works?

How the data is stored:

• The AAPL's details - market cap of 2,6 triillions and USA origin - are stored in a hash like below:
  • E.g HSET "company:AAPL" symbol "AAPL" market_cap "2600000000000" country USA
• The Ranks of AAPL of 2,6 trillions are stored in a ZSET.
  • E.g ZADD companyLeaderboard 2600000000000 company:AAPL

How the data is accessed:

• Top 10 companies:
  • E.g ZREVRANGE companyLeaderboard 0 9 WITHSCORES
• All companies:
  • E.g ZREVRANGE companyLeaderboard 0 -1 WITHSCORES
• Bottom 10 companies:
  • E.g ZRANGE companyLeaderboard 0 9 WITHSCORES
• Between rank 10 and 15:
  • E.g ZREVRANGE companyLeaderboard 9 14 WITHSCORES
• Show ranks of AAPL, FB and TSLA:
  • E.g ZSCORE companyLeaderBoard company:AAPL company:FB company:TSLA
• Adding market cap to companies:
  • E.g ZINCRBY companyLeaderBoard 1000000000 "company:FB"
• Reducing market cap to companies:
  • E.g ZINCRBY companyLeaderBoard -1000000000 "company:FB"
• Companies over a Trillion:
  • E.g ZCOUNT companyLeaderBoard 1000000000000 +inf
• Companies between 500 billion and 1 trillion:
  • E.g ZCOUNT companyLeaderBoard 500000000000 1000000000000

Code Example: Get top 10 companies

func (c Controller) Top10() ([]*Company, error) {
    companies, err := c.r.ZRevRange(keyLeaderBoard, 0, 9)
    if err != nil {
        return nil, err
    }
    c.buildCompanies(companies)
    c.buildRanks(companies)
    return companies, nil
}

How to run it locally?

Copy .env.example to create .env. And provide the values for environment variables if needed

• REDIS_HOST: Redis server host
• REDIS_PORT: Redis server port
• REDIS_PASSWORD: Password to the server

Configure by an environment variable with Redis connection string URL

It is possible to pass any valid Redis URL for Redis options as in ParseURL Example This way REDIS_HOST, REDIS_PORT, REDIS_PASSWORD are not needed.

• REDIS_URL=redis :// [[username :] password@] host [:port][/database]

• Example REDIS_URL="redis://p%40ssw0rd@redis-16379.hosted.com:16379/0" from redis-cli, the Redis command line interface

    Scheme syntax:
      Example: redis://user:secret@localhost:6379/0?foo=bar&qux=baz
  
      This scheme uses a profile of the RFC 3986 generic URI syntax.
      All URI fields after the scheme are optional.
      The "userinfo" field uses the traditional "user:password" format.
  

From Provisional RFC for Redis URIs

Secure a connection with Redis with a mutual TLS

To support this feature three new environment variables are introduced, TLS_CA_CERT_FILE, TLS_CERT_FILE, TLS_KEY_FILE. Their names are the same as "redis.conf" is using. They contain paths to respective files in a mounted secret volume. To use it with Kubernetes pods, add this to a container configuration:

spec:
  containers:
  - env:
      - name: TLS_CA_CERT_FILE
        value: /certs/ca.crt # path to CA certificate
      - name: TLS_CERT_FILE
        value: /certs/tls.crt # path to client certificate
      - name: TLS_KEY_FILE
        value: /certs/tls.key # path to client key
    image: ghcr.io/denist-huma/basic-redis-leaderboard-demo-go:1.2.2
    name: leaderboard-tls
    ports:
    - containerPort: 8080
      protocol: TCP
    volumeMounts:
    - mountPath: /certs
      name: leaderboard-tls-redis-client-cert

  volumes:
  - name: leaderboard-tls-redis-client-cert
    secret:
      defaultMode: 420
      secretName: leaderboard-tls-redis-client-cert

Where the secret "leaderboard-tls-redis-client-cert" has all three files we need. Here is a mere description, not the actual data:

apiVersion: v1
data:
  tls.crt:  1261 bytes
  tls.key:  1679 bytes
  ca.crt:   1415 bytes
kind: Secret
metadata:
  name: leaderboard-tls-redis-client-cert
type: kubernetes.io/tls

Run demo

go get
go run

Follow: http://localhost:8080

Try it out

(See notes: How to run on Google Cloud)

How to run on Google Cloud

1. Click "Run on Google Cloud"

Add the right values as per your infrastructure:

[ ? ] Value of REDIS_HOST environment variable (Redis server host) <Enter your Redis Host URL>
[ ? ] Value of REDIS_PORT environment variable (Redis server PORT) <Redis Port>
[ ? ] Value of REDIS_PASSWORD environment variable (Redis server password) <Redis Password>
[ ? ] Value of API_PUBLIC_PATH environment variable (Public path to frontend, example `/api/public`) /api/
[ ? ] Value of IMPORT_PATH environment variable (Path to seed.json file for import, example `/api/seed.json`) seed.json
[ ? ] Value of API_PORT environment variable (Api public port, example `8080`) 8080

Open up the link under "Manage this application at Cloud Console" to open up "Edit and Deploy New Revision”

2. Click “Variables and Secrets”

3. Verify the connector

3. Access the app

Hence, you should be able to access this app