AWS Test Deployment Considerations

This document describes a known-working AWS hosting pattern for a controlled BYOVA Gateway test environment. It shows how the gateway can sit behind an AWS Application Load Balancer (ALB) and call Amazon Lex V2. It is not a production deployment design, an infrastructure template, or a claim of production readiness.

All names and values below are placeholders. Do not add AWS account numbers, resource ARNs, instance IDs, subnet IDs, security-group IDs, target-group IDs, certificate IDs, access keys, tokens, or private deployment aliases to this repository.

Scope and validation boundary

The test pattern covered here has exercised these infrastructure behaviors:

Public DNS and a valid TLS certificate terminate at an internet-facing ALB.
The ALB accepts HTTP/2 gRPC traffic on TCP 443 and forwards it to the gateway’s gRPC listener on TCP 50051.
A separate target group can route limited HTTP health or diagnostic traffic to TCP 8080.
A single EC2 test host runs the Python gateway as a managed service.
Versioned runtime archives can be delivered through a private S3 bucket and installed through AWS Systems Manager (SSM), without public SSH access.
The gateway uses the standard AWS SDK credential chain; an EC2 workload role can authorize Amazon Lex discovery and runtime requests without static AWS access keys.
Gateway-owned BYODS registration and JWS renewal can run from host-owned environment configuration outside the release archive.

The ALB-to-EC2 hosting path is provider-neutral. Amazon Lex is selected at the connector layer. A healthy ALB target or successful gateway health request does not, by itself, prove that a particular Lex bot, Webex organization, or end-to-end call is working. Revalidate the Lex connector and a real test call after every material deployment or configuration change.

Known-working test topology

flowchart LR
    wxcc["Webex Contact Center<br/>BYOVA gRPC client"]
    dns["Public DNS<br/>test hostname"]
    alb["AWS Application Load Balancer<br/>TLS and HTTP/2 on 443"]
    grpc_tg["gRPC target group<br/>HTTP/2 gRPC to 50051"]
    http_tg["Restricted HTTP target group<br/>health or diagnostics to 8080"]
    ec2["Single EC2 test host<br/>gateway service"]
    lex["Amazon Lex V2<br/>control and runtime APIs"]
    webex["Webex identity and<br/>BYODS APIs"]
    s3["Private S3 bucket<br/>versioned runtime archives"]
    ssm["AWS Systems Manager<br/>test deployment access"]
    operator["Authorized test operator"]

    wxcc -->|"gRPC over TLS 443"| dns
    dns --> alb
    alb -->|"VoiceVirtualAgent and gRPC health paths"| grpc_tg
    alb -.->|"only when explicitly enabled"| http_tg
    grpc_tg --> ec2
    http_tg -.-> ec2
    ec2 -->|"AWS SDK over HTTPS"| lex
    ec2 -->|"HTTPS"| webex
    operator --> ssm
    ssm --> ec2
    s3 --> ec2

The monitoring interface is a development aid. Keep it disabled, private, or protected by appropriate authentication and network controls. Do not assume that publishing the gRPC endpoint also authorizes publishing the monitoring dashboard.

Resource responsibilities

Resource	Test-environment responsibility	Important considerations
DNS record	Resolves the test hostname to the ALB.	The hostname must match the certificate and the URL registered with BYODS. Use a placeholder in committed examples.
ACM certificate	Provides a valid certificate for the test hostname.	The certificate must be in the same AWS Region as the ALB. Prefer DNS validation and managed renewal.
Application Load Balancer	Terminates TLS and routes HTTP/2 gRPC traffic.	Use an HTTPS listener on port 443. Preserve gRPC metadata and confirm bidirectional streaming behavior.
gRPC target group	Sends BYOVA RPCs to gateway port 50051.	Use protocol `HTTP`, protocol version `GRPC`, and an explicit successful gRPC health code for the implemented health method.
HTTP target group	Optionally exposes `/health` or restricted diagnostics on port 8080.	Do not expose the dashboard publicly merely to obtain a health check. A dedicated health-only path is safer.
EC2 test host	Runs the gateway, connector, and optional monitoring process.	The observed test arrangement is a single host and is not highly available. Keep configuration and secrets outside release archives.
EC2 IAM role	Supplies short-lived AWS credentials to the gateway.	Grant only the required Lex, release-download, and management permissions. Do not store access keys on disk or in YAML.
Private S3 bucket	Stores versioned gateway runtime archives.	Block public access, encrypt objects, retain checksums, and scope read access to the test host or deployment role.
Systems Manager	Provides controlled host access and release installation.	Prefer Session Manager or Run Command over inbound SSH. Record command status without logging secret values.
Service manager	Starts, stops, and restarts the gateway process.	A test host can use `systemd`; keep environment files owner-readable only and preserve the last working release for rollback.

Listener and routing model

The external Webex endpoint uses one stable test URL:

https://<TEST_GATEWAY_HOSTNAME>

That exact URL must be used consistently for the BYODS datasource and JWT datasource URL. The external request path is:

Webex Contact Center
  -> DNS
  -> ALB HTTPS listener on 443
  -> gRPC path rule
  -> gRPC target group
  -> EC2 private address on 50051

The ALB listener needs rules for the gateway service and, when used, the standard gRPC health service. The current gateway service path is derived from the checked-in protobuf package and service name. Do not copy a path from an old deployment without comparing it with proto/.

The gateway application listener is intentionally plain HTTP/2 inside the test VPC. TLS ends at the ALB in this pattern. If the backend hop crosses an untrusted boundary, add backend TLS instead of reusing this test arrangement.

gRPC target health

The gateway implements grpc.health.v1.Health/Check. Configure the target group to call:

/grpc.health.v1.Health/Check

Because a successful implemented gRPC health method returns status code 0, configure the target-group health matcher to accept 0. The ALB default gRPC matcher is commonly used for an unimplemented method and should not be assumed correct for this gateway.

Treat target health as routing evidence only. It does not verify JWT claims, list the intended virtual agent, call Lex, or exercise a bidirectional caller stream.

Network controls

Use separate security groups for the ALB and EC2 test host.

ALB security group

Allow inbound TCP 443 from the client ranges appropriate for the test.
Allow inbound TCP 80 only when an HTTP-to-HTTPS redirect is required.
Do not allow inbound TCP 50051 or 8080 merely because those ports exist on the backend.
Allow outbound traffic to the EC2 security group on the target and health-check ports.

EC2 security group

Allow inbound TCP 50051 from the ALB security group only.
If the HTTP target group is enabled, allow inbound TCP 8080 from the ALB security group only.
Do not allow public inbound SSH. Use SSM for test administration.
Allow the outbound HTTPS paths required for Amazon Lex, Webex identity and BYODS APIs, S3, SSM, package installation, and any approved telemetry destination.

Security-group references are preferable to broad CIDR rules for ALB-to-host traffic. Never commit the resolved security-group IDs.

Amazon Lex access

Configure the Lex connector with a region and use the standard AWS SDK credential chain:

connectors:
  aws_lex_connector:
    type: "aws_lex_connector"
    class: "AWSLexConnector"
    module: "connectors.aws_lex_connector"
    config:
      region_name: "<AWS_REGION>"
      initial_trigger_text: "hello"
      barge_in_enabled: false

For the EC2 test arrangement, prefer an instance profile with a least-privilege role. The connector needs permission to discover configured bots and aliases and call the Lex runtime. See AWS Lex Connector Configuration for the current action list.

Do not place any of the following in config.yaml, a service unit, an archive, or Git:

AWS access-key IDs or secret access keys
AWS session tokens
Webex Service App client secrets or refresh tokens
Bot-specific secrets or customer data
Private deployment aliases or resource identifiers

Gateway and BYODS configuration

Use placeholders in source-controlled examples and supply environment-specific values on the test host:

gateway:
  host: "0.0.0.0"
  port: 50051

monitoring:
  enabled: false
  host: "127.0.0.1"
  port: 8080

jwt_validation:
  enabled: true
  enforce_validation: true
  datasource_url: "https://<TEST_GATEWAY_HOSTNAME>"
  datasource_schema_uuid: "<BYOVA_SCHEMA_UUID>"

data_source:
  enabled: true
  fail_startup_on_error: true
  url: "https://<TEST_GATEWAY_HOSTNAME>"
  schema_id: "<BYOVA_SCHEMA_UUID>"

The datasource and JWT URLs must match exactly. Keep the Service App credentials, refresh token, and any pinned datasource identifier in a host-owned environment file or approved secret store. Restrict a host environment file to the service owner and never print its contents during deployment or troubleshooting.

Versioned test release flow

Build the allowlisted runtime artifact from an explicit Git ref:

scripts/build-runtime-release.sh \
  --ref <GIT_REF> \
  --output /tmp/byova-gateway-runtime.tar.gz

The script reports the resolved commit and SHA-256 checksum. Before delivery:

Confirm the archive contains only the expected runtime paths.
Run the repository’s secret and dependency checks appropriate for the change.
Upload the archive under a unique, non-secret release name in a private S3 location.
Use SSM to download the exact object, verify its checksum, and unpack it into a new release directory.
Create or update the virtual environment from the release’s dependency metadata.
Preserve host-owned configuration, credentials, and environment files.
Change the service’s current-release pointer only after the new release is complete.
Restart the service and retain the prior release so the pointer can be restored if startup or validation fails.

Do not deploy the repository root. The runtime builder deliberately excludes tests, local tools, documentation, JavaScript dependencies, and workstation metadata.

Test verification

Verify each layer separately and record only sanitized results.

AWS routing

Confirm the active AWS identity belongs to the intended test account without recording its account number in repository artifacts.
Confirm the ALB is active and the expected HTTPS listener and path rules are present.
Confirm the gRPC and any explicitly enabled HTTP target groups report the intended EC2 target as healthy.
Confirm the certificate hostname and expiry are valid.

Gateway service

Confirm the managed service is active and points to the intended versioned release.
Confirm the gRPC health method succeeds through the ALB.
Call ListVirtualAgents with valid authentication and confirm the expected test agent is returned.
Confirm invalid or missing JWTs are rejected when enforcement is enabled.

An anonymous Unauthenticated response proves that traffic reached an enforcement point; it does not prove that the intended virtual agent is configured or callable.

Amazon Lex and Webex call path

Verify the intended Lex bot and alias are discoverable through the connector’s workload role.
Exercise a Lex text or buffered-audio request and confirm the expected response format.
Place a controlled Webex test call and correlate it to gateway logs with a conversation or tracking identifier.
Confirm greeting, caller input, bot response audio, terminal outcome, and any transfer path.
Check that no audio, transcript, token, or credential values were written to deployment output or routine logs.

Do not declare the deployment validated from an ALB health check, HTTP status, or process start alone.

Known test-environment limitations

This pattern intentionally stops short of a production design:

A single EC2 gateway target has no instance or Availability Zone redundancy.
In-memory conversation state is lost if the process or host stops.
Manual or SSM-driven release installation is not a production delivery pipeline.
The sample health endpoints are not complete readiness, saturation, or dependency checks.
The monitoring server is a development component, not a hardened administrative plane.
Capacity, concurrency, recovery time, and call behavior under infrastructure failure have not been certified for production.
TLS termination at the ALB leaves the backend hop unencrypted unless backend TLS is added.
The sample does not provide autoscaling, blue/green delivery, durable rollback automation, disaster recovery, SLO alerting, or multi-Region failover.

See Productization and Production Readiness before adapting this test pattern for any customer or production workload.