API gateway ni nini na kwa nini inatumika?

Question

Accepted Answer

**API gateway** ni ingizo moja tu ambalo linakaa mbele ya huduma zako za microservices. Wateja wanaita gateway, ambayo inaongeza ombi kwa huduma sahihi na kuhusu mambo yanayovuka kila kitu.

## Kinachofanya

- **Kusambaza** — peleka `/orders/*` kwa huduma ya matangazo.
- **Uthibitishaji** — thibitisha alama mara moja kwenye pembeni.
- **Kuzuia kasi** — lindani nyuma kwa matumizi mabaya.
- **Ujumlishi** — jumuisha kauli kadhaa za huduma katika jibu moja.
- **Kumaliza TLS, kurekodi, kuchacha.**

```text
            ┌─────────────────────────────┐
  Clients ─▶│        API Gateway          │
            │  auth · rate-limit · route  │
            └──┬──────────┬──────────┬────┘
               ▼          ▼          ▼
           Orders     Payments    Users
```

## Mfano wa usanidi

```yaml
# gateway routes
routes:
  - path: /orders/**
    service: orders-service   # forward order traffic here
    rateLimit: 100/min        # throttle abusive clients
  - path: /users/**
    service: users-service
    auth: required            # gateway enforces auth before routing
```

## Hatari

Gateway inaweza kuwa **nukta moja ya kushindwa** na kuzuia. Iendesheza kwa upatikaji wa juu na kamata mantiki ya biashara nje yake.

## Kwa nini inakadiriwa

Gateway huachilia kila huduma kutoka kuwa inarejesha uthibitishaji, kuzuia kasi, na TLS, na kuwapa wateja URL imara badala ya dusani.

Bila hiyo, wateja lazima wajue anwani ya kila huduma na kurudia mambo yanayovuka kila kitu, ambayo haraka inakuwa isiyoeleweka.