derive exported snapshot name

ansible/archival-snapshots/resources/main.sh

@@ -3,6 +3,9 @@
 ## Enable strict error handling, command tracing, and pipefail
 set -euxo pipefail
 
+GENESIS_TIMESTAMP=1598306400
+SECONDS_PER_EPOCH=30
+
 FOREST_CLI="/mnt/md0/exported/archival/forest-v0.17.1/forest-cli"
 FOREST_TOOL="/mnt/md0/exported/archival/forest-v0.17.1/forest-tool"
 
@@ -27,9 +30,17 @@ while ((LATEST_EPOCH - CURRENT_EPOCH > 30000)); do
    echo "Next Height: $NEW_EPOCH"
 
    # Export full snapshot to generate lite and diff snapshots
-   $FOREST_CLI snapshot export --tipset "$NEW_EPOCH" --depth 30000 > export.txt
-   NEW_SNAPSHOT=$(grep forest export.txt | awk -F'[:]' '{print $1}' | tail -1)
-   echo "New Snapshot Downloaded: $NEW_SNAPSHOT"
+   EPOCH_TIMESTAMP=$((GENESIS_TIMESTAMP + NEW_EPOCH*SECONDS_PER_EPOCH))
+   DATE=$(date --date=@"$EPOCH_TIMESTAMP" -u -I)
+   NEW_SNAPSHOT="forest_snapshot_mainnet_"$DATE"_height_"$NEW_EPOCH".forest.car.zst"
+
+   if [ ! -f "./$NEW_SNAPSHOT" ]; then
+        echo "Exporting snapshot: $NEW_SNAPSHOT"
+        $FOREST_CLI snapshot export --tipset "$NEW_EPOCH" --depth 30000 > export.txt
+        echo "Snapshot exported: $NEW_SNAPSHOT"
+    else
+        echo "$NEW_SNAPSHOT already exists."
+    fi
 
    # Generate and upload lite snapshot
    if [ ! -f "$LITE_SNAPSHOT_DIR/$NEW_SNAPSHOT" ]; then