move away from running expiry on interval - use fixed hh:mm

Signed-off-by: Utkarsh Srivastava <srivastavautkarsh8097@gmail.com>

config.js

@@ -758,9 +758,9 @@ config.NSFS_GLACIER_MIGRATE_INTERVAL = 15 * 60 * 1000;
 // of `manage_nsfs glacier restore`
 config.NSFS_GLACIER_RESTORE_INTERVAL = 15 * 60 * 1000;
 
-// NSFS_GLACIER_EXPIRY_INTERVAL indicates the interval between runs
-// of `manage_nsfs glacier expiry`
-config.NSFS_GLACIER_EXPIRY_INTERVAL = 12 * 60 * 60 * 1000;
+// NSFS_GLACIER_EXPIRY_RUN_TIME must be of the format hh:mm which specifies
+// when NooBaa should allow running glacier expiry process
+config.NSFS_GLACIER_EXPIRY_RUN_TIME = '03:00';
 
 /** @type {'UTC' | 'LOCAL'} */
 config.NSFS_GLACIER_EXPIRY_TZ = 'LOCAL';

src/manage_nsfs/manage_nsfs_glacier.js

@@ -69,12 +69,38 @@ async function process_expiry() {
     const fs_context = native_fs_utils.get_process_fs_context();
 
     await lock_and_run(fs_context, SCAN_LOCK, async () => {
-        if (!(await time_exceeded(fs_context, config.NSFS_GLACIER_EXPIRY_INTERVAL, GlacierBackend.EXPIRY_TIMESTAMP_FILE))) return;
+        const backend = getGlacierBackend();
+        if (
+            await backend.low_free_space() ||
+            is_desired_time(new Date(), config.NSFS_GLACIER_EXPIRY_RUN_TIME)
+        ) {
+            await backend.expiry(fs_context);
+        }
+    });
+}
 
+/**
+ * is_desired_time returns true if the given time matches with
+ * the desired time
+ * @param {Date} current
+ * @param {string} desire time in format 'hh:mm'
+ * @returns {Boolean}
+ */
+function is_desired_time(current, desire) {
+    const current_hour = current.getHours();
+    const current_min = current.getMinutes();
+
+    const [desired_hour, desired_min] = desire.split(':').map(Number);
+    if (
+        isNaN(desired_hour) ||
+        isNaN(desired_min) ||
+        (desired_hour < 0 || desired_hour >= 24) ||
+        (desired_min < 0 || desired_min >= 60)
+    ) {
+        throw new Error('invalid `NSFS_GLACIER_EXPIRY_RUN_TIME` - must be hh:mm');
+    }
 
-        await getGlacierBackend().expiry(fs_context);
-        await record_current_time(fs_context, GlacierBackend.EXPIRY_TIMESTAMP_FILE);
-    });
+    return desired_hour === current_hour && desired_min === current_min;
 }
 
 /**

src/sdk/nsfs_glacier_backend/backend.js

@@ -13,7 +13,6 @@ class GlacierBackend {
     // confuses these files with the WAL files.
     static MIGRATE_TIMESTAMP_FILE = 'migrate.timestamp';
     static RESTORE_TIMESTAMP_FILE = 'restore.timestamp';
-    static EXPIRY_TIMESTAMP_FILE = 'expiry.timestamp';
 
     /**
      * XATTR_RESTORE_REQUEST is set to a NUMBER (expiry days) by `restore_object` when 

src/sdk/nsfs_glacier_backend/tapecloud.js

@@ -278,7 +278,7 @@ class TapeCloudGlacierBackend extends GlacierBackend {
 
     async low_free_space() {
         const result = await exec(get_bin_path(LOW_FREE_SPACE_SCRIPT), { return_stdout: true });
-        return result.toLowerCase() === 'true';
+        return result.toLowerCase().trim() === 'true';
     }
 
     // ============= PRIVATE FUNCTIONS =============