new: [myc-update] check remaining space before starting

bin/myc-update

@@ -7,6 +7,37 @@ include common
 include pretty
 
 
+MIN_DISK_SPACE="${MIN_DISK_SPACE:-300M}"
+## convert human size to bytes using numfmt
+
+## Check remaining disk space
+if [ -n "$MIN_DISK_SPACE" ]; then
+    min_disk_space_kbytes=$(numfmt --from=iec --to-unit=1024 "$MIN_DISK_SPACE") || {
+        err "Invalid format for '\$MIN_DISK_SPACE'."
+        exit 1
+    }
+    if ! remaining_kbytes=$(df / | awk 'NR==2 {print $4}'); then
+        err "Failed to get remaining disk space."
+        exit 1
+    fi
+
+    if [ "$remaining_kbytes" -lt "$min_disk_space_kbytes" ]; then
+        err "Not enough disk space."
+        human_min_dist_space=$(numfmt --to=iec --format="%.2f" --from-unit=1024 "$min_disk_space_kbytes") || {
+            err "Failed to convert '\$MIN_DISK_SPACE' to human readable format."
+            exit 1
+        }
+        human_remaining_kbytes=$(numfmt --to=iec --format="%.2f" --from-unit=1024 "$remaining_kbytes") || {
+            err "Failed to convert '\$remaining_kbytes' to human readable format."
+            exit 1
+        }
+        echo "  - At least $human_min_dist_space are required." >&2
+        echo "  - Only $human_remaining_kbytes are available." >&2
+        exit 1
+    fi
+fi
+
+
 start=$SECONDS
 
 if [ -z "$NO_UPDATE" -a -d "/opt/apps/myc-manage" ]; then