Web UI

The briefing app ships a single-page application in the web/ directory, hosted on . Terraform handles config injection and deployment automatically — you only need to run terraform apply.

SPA structure

The web/ directory contains a static frontend with no build step:

File	Purpose
`index.html`	Main HTML shell — loads app.js and styles.css
`app.js`	Application logic — auth flow, API calls, rendering
`styles.css`	UI styling
`config.template.js`	Configuration template with placeholders for Terraform outputs

Config injection

The SPA needs runtime values (API endpoint, pool ID, etc.) that only exist after provisions the infrastructure. A template file bridges this gap.

Template placeholders

window.APP_CONFIG = {
  apiEndpoint: "__API_ENDPOINT__",
  cognitoPoolId: "__COGNITO_POOL_ID__",
  cognitoClientId: "__COGNITO_CLIENT_ID__",
  region: "__REGION__",
};

Generated config

During terraform apply, the templatefile() function replaces placeholders with actual values:

resource "local_file" "web_config" {
  content = templatefile("${path.module}/web/config.template.js", {
    __API_ENDPOINT__    = aws_apigatewayv2_stage.api.invoke_url
    __COGNITO_POOL_ID__ = aws_cognito_user_pool.pool.id
    __COGNITO_CLIENT_ID__ = aws_cognito_user_pool_client.client.id
    __REGION__          = var.region
  })
  filename = "${path.module}/web/config.js"
}

The resulting config.js is a plain JavaScript file that the SPA loads at runtime — no environment variables or build-time bundling needed.

Amplify hosting

Terraform provisions the app and branch for manual deployment (no auto-build from the repository):

resource "aws_amplify_app" "web" {
  name = "${var.project_name}-web"
}

resource "aws_amplify_branch" "main" {
  app_id      = aws_amplify_app.web.id
  branch_name = "main"
}

Deploy script

The scripts/deploy-web.sh script packages the web/ directory and uploads it to Amplify:

#!/bin/bash
# 1. Create a zip archive of web/ contents (including generated config.js)
# 2. Start a new Amplify deployment
# 3. Upload the zip to the deployment URL
# 4. Wait for deployment to complete

APP_ID="$1"
BRANCH_NAME="$2"

cd web/
zip -r /tmp/web-deploy.zip .

DEPLOY_URL=$(aws amplify create-deployment \
  --app-id "$APP_ID" \
  --branch-name "$BRANCH_NAME" \
  --query 'zipUploadUrl' --output text)

curl -T /tmp/web-deploy.zip "$DEPLOY_URL"

Terraform invokes this script via a null_resource:

resource "null_resource" "deploy_web" {
  triggers = {
    web_hash    = sha256(join("", [for f in fileset("web/", "**") : filesha256("web/${f}")]))
    config_hash = sha256(local_file.web_config.content)
  }

  provisioner "local-exec" {
    command = "bash scripts/deploy-web.sh ${aws_amplify_app.web.id} main"
  }

  depends_on = [local_file.web_config]
}

The triggers block re-runs the script whenever:

Any file in web/ changes (source code updates)
The generated config.js content changes (infrastructure changes like a new API endpoint)

Accessing the UI

After deployment completes, get the app URL from Terraform outputs:

terraform output -raw app_url

Open the URL in a browser and sign in with your Cognito credentials (see Cognito Users).

Redeployment

Automatic

Redeployment triggers automatically on the next terraform apply when:

You modify any file in the web/ directory
Infrastructure changes cause config.js to regenerate (e.g., new API Gateway stage, different region)

Manual

Force a redeployment without changing any source files:

terraform apply -replace=null_resource.deploy_web