feat(aws/ec2): add instance type recommender

aws/ec2/recommend_instance_types.sh

@@ -0,0 +1,118 @@
+#!/usr/bin/env bash
+# Recommend the five cheapest current-generation EC2 instance types for a given
+# architecture, memory size, and vCPU count. Prices are on-demand Linux, shared
+# tenancy, in the active AWS region.
+#
+# Requires the AWS CLI and jq (brew install jq).
+set -euo pipefail
+
+usage() {
+  echo "Usage: $0 [x86|arm] [memory-gib] [vcpus]" >&2
+  echo "Any argument left out is prompted for." >&2
+  exit 1
+}
+
+normalize_architecture() {
+  case "$(tr '[:upper:]' '[:lower:]' <<<"$1")" in
+    x86 | x86_64 | amd64 | intel | amd) echo "x86_64" ;;
+    arm | arm64 | aarch64 | graviton) echo "arm64" ;;
+    *)
+      echo "Unknown architecture: $1 (expected x86 or arm)" >&2
+      exit 1
+      ;;
+  esac
+}
+
+require_positive_integer() {
+  if ! [[ "$2" =~ ^[1-9][0-9]*$ ]]; then
+    echo "$1 must be a positive integer, received: $2" >&2
+    exit 1
+  fi
+}
+
+[[ $# -gt 3 ]] && usage
+
+architecture_input="${1:-}"
+memory_gib="${2:-}"
+vcpus="${3:-}"
+
+if [[ -z "$architecture_input" ]]; then
+  read -r -p "Architecture [x86/arm] (default x86): " architecture_input
+  architecture_input="${architecture_input:-x86}"
+fi
+if [[ -z "$memory_gib" ]]; then
+  read -r -p "Memory in GiB (default 8): " memory_gib
+  memory_gib="${memory_gib:-8}"
+fi
+if [[ -z "$vcpus" ]]; then
+  read -r -p "vCPUs (default 4): " vcpus
+  vcpus="${vcpus:-4}"
+fi
+
+architecture="$(normalize_architecture "$architecture_input")"
+require_positive_integer "Memory" "$memory_gib"
+require_positive_integer "vCPUs" "$vcpus"
+
+region="${AWS_REGION:-$(aws configure get region || true)}"
+if [[ -z "$region" ]]; then
+  echo "AWS region is not set. Export AWS_REGION or run 'aws configure'." >&2
+  exit 1
+fi
+
+candidates="$(aws ec2 describe-instance-types \
+  --region "$region" \
+  --filters \
+    "Name=processor-info.supported-architecture,Values=${architecture}" \
+    "Name=vcpu-info.default-vcpus,Values=${vcpus}" \
+    "Name=memory-info.size-in-mib,Values=$((memory_gib * 1024))" \
+    "Name=current-generation,Values=true" \
+  --query 'InstanceTypes[].{type:InstanceType,network:NetworkInfo.NetworkPerformance,burstable:BurstablePerformanceSupported,localDisk:InstanceStorageSupported}' \
+  --output json)"
+
+if [[ "$(jq 'length' <<<"$candidates")" -eq 0 ]]; then
+  echo "No current-generation ${architecture} instance types with ${vcpus} vCPUs and ${memory_gib} GiB in ${region}." >&2
+  exit 1
+fi
+
+# The Pricing API is only served from a few regions; us-east-1 carries every region's price list.
+prices="$(aws pricing get-products \
+  --region us-east-1 \
+  --service-code AmazonEC2 \
+  --filters \
+    "Type=TERM_MATCH,Field=regionCode,Value=${region}" \
+    "Type=TERM_MATCH,Field=operatingSystem,Value=Linux" \
+    "Type=TERM_MATCH,Field=tenancy,Value=Shared" \
+    "Type=TERM_MATCH,Field=preInstalledSw,Value=NA" \
+    "Type=TERM_MATCH,Field=capacitystatus,Value=Used" \
+    "Type=TERM_MATCH,Field=vcpu,Value=${vcpus}" \
+    "Type=TERM_MATCH,Field=memory,Value=${memory_gib} GiB" \
+  --query 'PriceList' \
+  --output json)"
+
+echo
+echo "Cheapest on-demand Linux ${architecture} instance types with ${vcpus} vCPUs and ${memory_gib} GiB in ${region}:"
+echo
+jq -r --argjson candidates "$candidates" '
+  ($candidates | map({key: .type, value: .}) | from_entries) as $specs
+  | map(fromjson)
+  | map({
+      type: .product.attributes.instanceType,
+      processor: .product.attributes.physicalProcessor,
+      hourly: (.terms.OnDemand[] | .priceDimensions[] | .pricePerUnit.USD | tonumber)
+    })
+  | map(select($specs[.type] != null and .hourly > 0))
+  | sort_by(.hourly)
+  | unique_by(.type)
+  | sort_by(.hourly)
+  | .[:5]
+  | (["TYPE", "USD/HR", "USD/MONTH", "NETWORK", "BURSTABLE", "LOCAL_DISK", "PROCESSOR"] | @tsv),
+    (.[] | [
+      .type,
+      (.hourly * 10000 | round / 10000),
+      (.hourly * 730 * 100 | round / 100),
+      $specs[.type].network,
+      $specs[.type].burstable,
+      $specs[.type].localDisk,
+      .processor
+    ] | @tsv)
+' <<<"$prices" | column -t -s $'\t'