AWS Shared ALB

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Creates a standalone ALB shared across multiple services. Shows advanced routing with path conditions, header conditions, and health checks.

sst.config.ts

const alb = new sst.aws.Alb("SharedAlb", {
  vpc,
  listeners: [
    { port: 80, protocol: "http" },
  ],
});

Services can use header-based routing in addition to path-based:

sst.config.ts

new sst.aws.Service("InternalApi", {
  cluster,
  image: { context: "api/" },
  loadBalancer: {
    instance: alb,
    rules: [
      {
        listen: "80/http",
        forward: "3000/http",
        conditions: {
          path: "/api/*",
          header: { name: "x-internal", values: ["true"] },
        },
        priority: 50,
      },
    ],
  },
});

This example creates:

• A shared ALB with an HTTP listener
• An API service with path-based routing and custom health check
• A Web service with path-based routing
• Both services share the same ALB

sst.config.ts

const vpc = new sst.aws.Vpc("MyVpc");
const cluster = new sst.aws.Cluster("MyCluster", { vpc });

// Create a shared ALB with an HTTP listener
const alb = new sst.aws.Alb("SharedAlb", {
  vpc,
  listeners: [{ port: 80, protocol: "http" }],
});

// API service — handles /api/* with a custom health check path
new sst.aws.Service("Api", {
  cluster,
  image: { context: "api/" },
  loadBalancer: {
    instance: alb,
    rules: [
      {
        listen: "80/http",
        forward: "3000/http",
        conditions: { path: "/api/*" },
        priority: 100,
      },
    ],
    health: {
      "3000/http": {
        path: "/api/health",
        interval: "10 seconds",
        timeout: "5 seconds",
        healthyThreshold: 2,
        unhealthyThreshold: 3,
      },
    },
  },
});

// Web service — handles everything else under /app/*
new sst.aws.Service("Web", {
  cluster,
  image: { context: "web/" },
  loadBalancer: {
    instance: alb,
    rules: [
      {
        listen: "80/http",
        forward: "3000/http",
        conditions: { path: "/app/*" },
        priority: 200,
      },
    ],
    health: {
      "3000/http": {
        path: "/app/health",
        interval: "10 seconds",
        timeout: "5 seconds",
      },
    },
  },
});

View the full example.