Copy secrets from one Azure Key Vault to another assuming they're both in the same Azure subscription

migrate_kv.sh

#!/bin/bash
set -euo pipefail

SOURCE_KV="<source_key_vault_name>"
DEST_KV="<destination_key_vault_name>"

SOURCE_SECRETS=$(az keyvault secret list --vault-name $SOURCE_KV --query "[].id" -o tsv | cut -d "/" -f5)
DEST_SECRETS=$(az keyvault secret list --vault-name $DEST_KV --query "[].id" -o tsv | cut -d "/" -f5)
MISSING_SECRETS=$(echo "${SOURCE_SECRETS} ${DEST_SECRETS}" | tr ' ' '\n' | sort | uniq -u)

for MISSING_SECRET in $MISSING_SECRETS
do
    MISSING_VALUE=$(az keyvault secret show --vault-name $SOURCE_KV -n $MISSING_SECRET --query "value" -o tsv)
    az keyvault secret set --vault-name $DEST_KV -n $MISSING_SECRET --value "$MISSING_VALUE"
done

Very helpful. Thanks!