add unqualified-images migration helper

Author: frobware

contrib/migration/unqualified-images.sh

@@ -0,0 +1,65 @@
+#!/bin/bash
+
+# List all unqualified images in all pods in all namespaces.
+
+strindex() {
+    local x="${1%%$2*}"		# find occurrence of $2 in $1
+    [[ "$x" == "$1" ]] && echo -1 || echo "${#x}"
+}
+
+# Finds any-of chars in string. Returns 0 on success, otherwise 1.
+strchr() {
+    local str=$1
+    local chars=$2
+    for (( i=0; i<${#chars}; i++ )); do
+	[[ $(strindex "$str" "${chars:$i:1}") -ge 0 ]] && return 0
+    done
+    return 1
+}
+
+split_image_at_domain() {
+    local image=$1
+    local index=$(strindex "$image" "/")
+
+    if [[ "$index" == -1 ]] || (! strchr "${image:0:$index}" ".:" && [[ "${image:0:$index}" != "localhost" ]]); then
+	echo ""
+    else
+	echo "${image:0:$index}"
+    fi
+}
+
+has_domain() {
+    local image=$1
+    [[ -n $(split_image_at_domain "$image") ]]
+}
+
+die() {
+    echo "$*" 1>&2
+    exit 1
+}
+
+self_test() {
+    strchr "foo/busybox" "Z"            && die "self-test 1 failed"
+
+    strchr "foo/busybox" "/"            || die "self-test 2 failed"
+    strchr "foo/busybox" "Zx"           || die "self-test 3 failed"
+
+    has_domain "foo"			&& die "self-test 4 failed"
+    has_domain "foo/busybox"		&& die "self-test 5 failed"
+    has_domain "repo/foo/busybox"	&& die "self-test 6 failed"
+    has_domain "a/b/c/busybox"          && die "self-test 7 failed"
+
+    has_domain "localhost/busybox"	|| die "self-test 8 failed"
+    has_domain "localhost:5000/busybox" || die "self-test 9 failed"
+    has_domain "foo.com:5000/busybox"	|| die "self-test 10 failed"
+    has_domain "docker.io/busybox"	|| die "self-test 11 failed"
+    has_domain "a.b.c.io/busybox"	|| die "self-test 12 failed"
+}
+
+[[ -n ${SELF_TEST:-yes} ]] && self_test
+
+images="$(kubectl get pods --all-namespaces -o jsonpath="{.items[*].spec.containers[*].image}")"
+
+for image in $images; do
+    has_domain "$image" || echo "$image"
+done