/amazon-keyspaces

PDF reporting

PDF generation is optional and never automatic. Ask the user after showing the JSON estimate. Skip for Mode 3 (compatibility-only) because there is no pricing data to render; direct the user to Mode 2 for a combined report.

Command

cd scripts
npx ts-node --project tsconfig.scripts.json generate-pdf.ts \
  --input <path.json> [--label <name>] [--output <path.pdf>]

Flags

• --input <path> — path to a calculate.ts or parse-cassandra.ts JSON file. Repeatable for multi-estimate reports.
• --label <name> — display label for the most recent --input. Optional; defaults to Estimate 1, Estimate 2, … in command-line order. Used in the comparison summary table and in per-estimate section headers.
• --output <path> — PDF output path. Defaults to ./keyspaces-pricing-estimate.pdf in the current working directory.

Modes

Single estimate — one --input (or JSON on stdin, for backwards compatibility):

# From a file
npx ts-node --project tsconfig.scripts.json generate-pdf.ts \
  --input /tmp/keyspaces-calc.json --output /tmp/keyspaces.pdf

# From stdin (single estimate only)
cat /tmp/keyspaces-calc.json \
  | npx ts-node --project tsconfig.scripts.json generate-pdf.ts \
  --output /tmp/keyspaces.pdf

Renders a single-estimate report — title page, inputs summary, cost tables (on-demand + provisioned + Savings Plan), per-keyspace breakdown if present, and a compatibility section if the JSON contains one.

Multiple estimates — two or more --input flags:

npx ts-node --project tsconfig.scripts.json generate-pdf.ts \
  --input /tmp/a.json --label "Option A — Denorm" \
  --input /tmp/b.json --label "Option B — Normalized" \
  --input /tmp/c.json --label "Option C — Reverse Index" \
  --output /tmp/keyspaces-comparison.pdf

Renders a consolidated comparison report — a side-by-side summary table (storage, reads/s, writes/s, on-demand/mo, OD+SP/mo, provisioned/mo, prov+SP/mo), followed by a per-estimate section for each input.

When to use multi-input vs one-at-a-time

Always use a single multi-input invocation when the user has more than one estimate to report:

• Mode 4 always has three estimates (Denorm / Normalized / Reverse Index).
• Mode 1 sensitivity runs — when the user wants to compare two or three traffic scenarios.
• Mode 2 multi-cluster — when the user is migrating two or more separate Cassandra clusters.

Avoid generating one PDF per estimate — the consolidated comparison table is the entire point.

EAGAIN on stdin

If generate-pdf.ts throws EAGAIN: resource temporarily unavailable, read, the upstream ts-node process closed stdin before this process read it. Write the JSON to a file and pass --input <path> instead of piping. This is a Node.js timing behavior, not a bug in the script.

Saving the intermediate JSON

The scripts print pricing JSON to stdout. Always tee or redirect into /tmp/keyspaces-*.json:

npx ts-node --project tsconfig.scripts.json calculate.ts \
  us-east-1 1000 500 1024 100 0 false \
  | tee /tmp/keyspaces-calc.json

Then PDF generation can reuse the same file without rerunning pricing. This is also how you produce multi-input comparisons — one calculate.ts or parse-cassandra.ts call per scenario, each to its own /tmp/*.json, then one generate-pdf.ts pulling them all.

Output path conventions

• Default filename: keyspaces-pricing-estimate.pdf in the current directory.
• For Mode 4: keyspaces-sql-comparison.pdf or similar descriptive name.
• For cluster comparisons: include cluster names or dates in the filename so the user can distinguish reports later.

Prefer an absolute path in --output when running inside a skill so the user knows where to find the file afterward.

What the PDF contains

Every PDF includes:

1. Title page — skill name, date, input summary.
2. Cost summary — on-demand vs provisioned vs Savings Plan tiers, line-item breakdown.
3. Per-keyspace / per-datacenter breakdown (Mode 2 only).
4. Compatibility findings — when the source JSON includes a compatibility block.
5. Recommendation — implicit (whichever total is lowest), reinforced by the table formatting.

The PDF does not include raw capture files, node hostnames, or credentials. If the user wants a deeper audit trail, keep the intermediate JSON alongside the PDF.

Non-goals

• The PDF renderer does not fetch live pricing. All rates come from assets/data/*.json, which is a snapshot. When prices drift, the skill owner refreshes these files from AWS Pricing APIs.
• The PDF does not run the pricing calculation — it only renders pre-computed JSON. If the JSON is stale, regenerate it first.
• PDF generation does not modify any AWS resources. It is an output-only operation.