Some housekeeping changes and new script to make regression testing easier

ec2-metadata

@@ -53,7 +53,7 @@ QUIET=""
 function set_imds_token()
 {
 	if [ -z "${IMDS_TOKEN}" ];then
-		IMDS_TOKEN=$(curl -s -f -X PUT -H "X-aws-ec2-metadata-token-ttl-seconds: 900" ${METADATA_BASEURL}/${METADATA_TOKEN_PATH})
+		IMDS_TOKEN=$(curl -s -f -X PUT -H "X-aws-ec2-metadata-token-ttl-seconds: 900" "${METADATA_BASEURL}/${METADATA_TOKEN_PATH}")
 		if [ "${?}" -gt 0 ] || [ -z "${IMDS_TOKEN}" ]; then
 			echo '[ERROR] Could not get IMDSv2 token. Instance Metadata might have been disabled or this is not an EC2 instance.' >&2
 			exit 1
@@ -65,15 +65,15 @@ function set_imds_token()
 function get_meta()
 {
 	local imds_out
-	imds_out=$(curl -s -q -H "X-aws-ec2-metadata-token:${IMDS_TOKEN}" -f ${METADATA_BASEURL}/${METADATA_VERSION}/${1})
+	imds_out=$(curl -s -q -H "X-aws-ec2-metadata-token:${IMDS_TOKEN}" -f "${METADATA_BASEURL}/${METADATA_VERSION}/${1}")
 	echo -n "${imds_out}"
 }
 
 #print standard metric
 function print_normal_metric() {
 	metric_path=$2
-    [ -z "$QUIET" ] && echo -n $1": "
-	RESPONSE=$(get_meta ${metric_path})
+	[ -z "$QUIET" ] && echo -n "$1: "
+	RESPONSE=$(get_meta "${metric_path}")
 	if [ -n "${RESPONSE}" ]; then
 		echo "$RESPONSE"
 	else
@@ -82,35 +82,35 @@ function print_normal_metric() {
 }
 
 #print block-device-mapping
-function print_block-device-mapping()
+function print_block_device_mapping()
 {
 	[ -z "$QUIET" ] && echo 'block-device-mapping: '
 	x=$(get_meta meta-data/block-device-mapping/)
 	if [ -n "${x}" ]; then
 		for i in $x; do
-            [ -z "$QUIET" ] && echo -ne '\t' "$i: "
-            echo "$(get_meta meta-data/block-device-mapping/$i)"
+			[ -z "$QUIET" ] && echo -ne '\t' "$i: "
+			echo "$(get_meta "meta-data/block-device-mapping/$i")"
 		done
 	else
 		echo not available
 	fi
 }
 
 #print public-keys
-function print_public-keys()
+function print_public_keys()
 {
 	[ -z "$QUIET" ] && echo 'public-keys: '
 	x=$(get_meta meta-data/public-keys/)
 	if [ -n "${x}" ]; then
 		for i in $x; do
-			index=$(echo $i|cut -d = -f 1)
-			keyname=$(echo $i|cut -d = -f 2)
-			[ -z "$QUIET" ] && echo keyname:$keyname
-			[ -z "$QUIET" ] && echo index:$index
-			format=$(get_meta meta-data/public-keys/$index/)
-			[ -z "$QUIET" ] && echo format:$format
+			index=$(echo "$i" | cut -d = -f 1)
+			keyname=$(echo "$i" | cut -d = -f 2)
+			[ -z "$QUIET" ] && echo "keyname:$keyname"
+			[ -z "$QUIET" ] && echo "index:$index"
+			format=$(get_meta "meta-data/public-keys/$index/")
+			[ -z "$QUIET" ] && echo "format:$format"
 			[ -z "$QUIET" ] && echo 'key:(begins from next line)'
-			echo "$(get_meta meta-data/public-keys/$index/$format)"
+			echo "$(get_meta "meta-data/public-keys/$index/$format")"
 		done
 	else
 		echo not available
@@ -124,8 +124,8 @@ function print_tags()
 	x=$(get_meta meta-data/tags/instance/)
 	if [ -n "${x}" ]; then
 		for i in $x; do
-            echo -n -e '\t' "$i: "
-            echo "$(get_meta meta-data/tags/instance/$i)"
+			echo -n -e '\t' "$i: "
+			echo "$(get_meta "meta-data/tags/instance/$i")"
 		done
 	else
 		echo not available
@@ -138,7 +138,7 @@ function print_all()
 	print_normal_metric ami-launch-index meta-data/ami-launch-index
 	print_normal_metric ami-manifest-path meta-data/ami-manifest-path
 	print_normal_metric ancestor-ami-ids meta-data/ancestor-ami-ids
-	print_block-device-mapping
+	print_block_device_mapping
 	print_normal_metric instance-id meta-data/instance-id
 	print_normal_metric instance-type meta-data/instance-type
 	print_normal_metric local-hostname meta-data/local-hostname
@@ -150,7 +150,7 @@ function print_all()
 	print_normal_metric product-codes meta-data/product-codes
 	print_normal_metric public-hostname meta-data/public-hostname
 	print_normal_metric public-ipv4 meta-data/public-ipv4
-	print_public-keys
+	print_public_keys
 	print_normal_metric ramdisk-id /meta-data/ramdisk-id
 	print_normal_metric reservation-id /meta-data/reservation-id
 	print_normal_metric security-groups meta-data/security-groups
@@ -191,49 +191,49 @@ declare -a actions
 declare -a paths
 shortopts=almnbithokzPcpvuresdgR
 longopts=(ami-id ami-launch-index ami-manifest-path ancestor-ami-ids block-device-mapping
-          instance-id instance-type local-hostname local-ipv4 kernel-id availability-zone
-          partition product-codes public-hostname public-ipv4 public-keys ramdisk-id
-          reservation-id security-groups user-data tags region help all quiet path:)
+	instance-id instance-type local-hostname local-ipv4 kernel-id availability-zone
+	partition product-codes public-hostname public-ipv4 public-keys ramdisk-id
+	reservation-id security-groups user-data tags region help all quiet path:)
 
 oldIFS="$IFS"
 IFS=,
 TEMP=$(getopt -o $shortopts --longoptions "${longopts[*]}" -n 'ec2-metadata' -- "$@")
 if [ $? -ne 0 ]; then
-    echo 'Terminating...' >&2
-    exit 1
+	echo 'Terminating...' >&2
+	exit 1
 fi
 IFS="$oldIFS"
 
 eval set -- "$TEMP"
 unset TEMP
 
 while true; do
-    case "$1" in
-        --help)
-            print_help ; shift
-            exit 0
-            ;;
-        --quiet)
-            QUIET=1 ; shift
-            ;;
-        --path)
-            actions+=("$1")
-            paths+=("$2")
-            shift 2
-            ;;
-        --)
-            shift ; break
-            ;;
-        --?*|-?)
-            # pass most arguments to the original action processing
-            # code after setting options
-            actions+=("$1"); shift
-            ;;
-        *)
-            echo 'Unknown error: ' "[$1]" >&2
-            exit 1
-            ;;
-    esac
+	case "$1" in
+		--help)
+			print_help ; shift
+			exit 0
+			;;
+		--quiet)
+			QUIET=1 ; shift
+			;;
+		--path)
+			actions+=("$1")
+			paths+=("$2")
+			shift 2
+			;;
+		--)
+			shift ; break
+			;;
+		--?*|-?)
+			# pass most arguments to the original action processing
+			# code after setting options
+			actions+=("$1"); shift
+			;;
+		*)
+			echo 'Unknown error: ' "[$1]" >&2
+			exit 1
+			;;
+	esac
 done
 
 #start processing command line arguments
@@ -243,7 +243,7 @@ for action in "${actions[@]}"; do
 	    -l | --ami-launch-index )      print_normal_metric ami-launch-index meta-data/ami-launch-index ;;
 	    -m | --ami-manifest-path )     print_normal_metric ami-manifest-path meta-data/ami-manifest-path ;;
 	    -n | --ancestor-ami-ids )      print_normal_metric ancestor-ami-ids meta-data/ancestor-ami-ids ;;
-	    -b | --block-device-mapping )  print_block-device-mapping ;;
+	    -b | --block-device-mapping )  print_block_device_mapping ;;
 	    -i | --instance-id )           print_normal_metric instance-id meta-data/instance-id ;;
 	    -t | --instance-type )         print_normal_metric instance-type meta-data/instance-type ;;
 	    -h | --local-hostname )        print_normal_metric local-hostname meta-data/local-hostname ;;
@@ -255,7 +255,7 @@ for action in "${actions[@]}"; do
 	    -c | --product-codes )         print_normal_metric product-codes meta-data/product-codes ;;
 	    -p | --public-hostname )       print_normal_metric public-hostname meta-data/public-hostname ;;
 	    -v | --public-ipv4 )           print_normal_metric public-ipv4 meta-data/public-ipv4 ;;
-	    -u | --public-keys )           print_public-keys ;;
+	    -u | --public-keys )           print_public_keys ;;
 	    -r | --ramdisk-id )            print_normal_metric ramdisk-id /meta-data/ramdisk-id ;;
 	    -e | --reservation-id )        print_normal_metric reservation-id /meta-data/reservation-id ;;
 	    -s | --security-groups )       print_normal_metric security-groups meta-data/security-groups ;;

tests/README.md

@@ -0,0 +1,26 @@
+# ec2-metadata regression testing
+
+`capture-output.sh` runs every `ec2-metadata` subcommand and saves each output to a separate file. This lets you compare output before and after a code change to catch regressions.
+
+## Usage
+
+```bash
+# 1. Capture baseline output (before your changes)
+./capture-output.sh output-before
+
+# 2. Make your changes to ec2-metadata
+
+# 3. Capture output again
+./capture-output.sh output-after
+
+# 4. Compare
+diff -r output-before output-after
+```
+
+No diff output means the change is behavior-preserving. Any differences will show exactly which subcommand's output changed and how.
+
+## Notes
+
+- Must be run on an EC2 instance (requires IMDS access).
+- The subcommand list is derived dynamically from `ec2-metadata --help`, so new options are picked up automatically.
+- Individual subcommand failures are logged as warnings but don't stop the run, so you get partial results even if some metadata categories are unavailable.

tests/capture-output.sh

@@ -0,0 +1,29 @@
+#!/usr/bin/bash
+# Capture ec2-metadata output for each subcommand into a directory.
+# Usage: ./capture-output.sh [output-dir]
+#   default output-dir: output
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+EC2_METADATA="${SCRIPT_DIR}/../ec2-metadata"
+OUTDIR="${1:-output}"
+
+[[ -x "$EC2_METADATA" ]] || { echo "ERROR: ec2-metadata not found at $EC2_METADATA" >&2; exit 1; }
+
+mapfile -t cmds < <("$EC2_METADATA" --help | grep -oP '(?<=/--)[a-z][-a-z0-9]+' | grep -v 'help\|quiet\|all\|path')
+if [[ ${#cmds[@]} -eq 0 ]]; then
+	echo "ERROR: No subcommands found in --help output" >&2
+	exit 1
+fi
+
+mkdir -p "$OUTDIR"
+
+for cmd in "${cmds[@]}"; do
+	"$EC2_METADATA" --"$cmd" > "$OUTDIR/$cmd.txt" 2>&1 || echo "WARN: --$cmd failed" >&2
+done
+
+"$EC2_METADATA" > "$OUTDIR/default.txt" 2>&1 || echo "WARN: default (no args) failed" >&2
+
+files=("$OUTDIR"/*.txt)
+echo "Captured ${#files[@]} files in $OUTDIR/"