Merge pull request #32 from art19/ziggythehamster/make-ec2nvme-nsid-bash-only

Change ec2nvme-nsid to use Bash built-ins

Author: vigh-m

amazon-ec2-utils.spec

@@ -1,6 +1,6 @@
 Name:      amazon-ec2-utils
 Summary:   A set of tools for running in EC2
-Version:   2.1.0
+Version:   2.2.0
 Release:   1%{?dist}
 License:   MIT
 Group:     System Tools
@@ -75,6 +75,9 @@ rm -rf $RPM_BUILD_ROOT
 /etc/udev/rules.d/60-cdrom_id.rules
 
 %changelog
+* Thu Jan 18 2024 Keith Gable <gablk@amazon.com> - 2.2.0-1
+- Change ec2nvme-nsid to use Bash string manipulation to improve
+  performance and reliability
 
 * Thu Apr  6 2023 Noah Meyerhans <nmeyerha@amazon.com> - 2.1.0-1
 - Add --quiet option to ec2-metadata

ec2nvme-nsid

@@ -6,11 +6,18 @@
 # for the specific language governing permissions and limitations under
 # the License.
 
-#Expected input if partition's kernel name like nvme0n1p2
-if [ $# -eq 0 ] ; then
+# Expected input is partition's kernel name like nvme0n1p2 or nvme0n1, output would be 1
+
+if [[ $# -ne 1 ]]; then
   exit 1
 else
-  # extract ns id from partition's kernel name and export it
-  NSID=$(echo -n "$@" | cut -f 3 -d 'n' | cut -f 1 -d 'p')
+  kernel_name=$1
+
+  # Remove nvme prefix (also deals with any /dev that might accidentally get passed in)
+  prefix_removed=${kernel_name#*nvme*n}
+  
+  # Remove partition suffix
+  NSID=${prefix_removed%p*}
+
   echo "_NS_ID=${NSID}"
 fi