Fixed tracing bug

The copying operation is now run as a separate script so that the emitted traces actually close.

Author: clintonb

.dockerignore

@@ -1,4 +1,5 @@
 *
 !docker-build-resources/etc
 !docker-build-resources/opentelemetry-shell/library
-!docker-build-resources/sync.sh
+!docker-build-resources/copy-database.sh
+!docker-build-resources/watch.sh

Dockerfile

@@ -27,6 +27,7 @@ ENV LITEFS_INTERNAL_DATA_DIRECTORY=/var/lib/litefs
 
 WORKDIR /
 COPY docker-build-resources/opentelemetry-shell /opentelemetry-shell
-COPY docker-build-resources/sync.sh /sync.sh
+COPY docker-build-resources/watch.sh /watch.sh
+COPY docker-build-resources/copy-database.sh /copy-database.sh
 
 ENTRYPOINT litefs mount

docker-build-resources/copy-database.sh

@@ -0,0 +1,77 @@
+#!/bin/bash
+
+# This script copies a synced database to the host and emits an Otel signal.
+
+set -e
+set +v
+set +x
+
+# OpenTelemetry setup
+export OTEL_EXPORTER_OTEL_ENDPOINT="http://host.docker.internal:4318"
+export OTEL_SH_LIB_PATH="opentelemetry-shell/library"
+# shellcheck disable=SC2034
+service_version=$OTEL_SERVICE_VERSION
+. opentelemetry-shell/library/otel_traces.sh
+
+Normal='\033[0m'
+Red='\033[0;31m'
+Green='\033[0;32m'
+Yellow='\033[0;33m'
+
+name="$1"
+path="$LITEFS_DB_DIRECTORY/$name"
+
+echo "Attempting to copy $path..."
+
+if test -f "$path"; then
+  sourcePath="$LITEFS_DB_DIRECTORY/$name"
+  destPath="/host-data/$(date +"%s")-$name"
+
+  stat "$sourcePath"
+
+  if test -s "$sourcePath"; then
+    # NOTE: We execute the restore in the container since it is more performant than restoring on a host volume.
+    echo -e "${Yellow}Copying $sourcePath to $destPath...${Normal}"
+
+    # Create an Otel span
+    generatedAt=$(sqlite3 "$sourcePath" "SELECT generated_at FROM metadata;")
+    schemaVersion=$(sqlite3 "$sourcePath" "SELECT schema_version FROM metadata;")
+    # shellcheck disable=SC2034
+    span_name="Copy domain data to host"
+    # shellcheck disable=SC2034
+    custom_resource_attributes=(
+      "domain_data_generated_at:$generatedAt"
+      "domain_data_schema_version:$schemaVersion"
+    )
+    linkedTraceId=$(sqlite3 "$sourcePath" "SELECT linked_trace_id FROM metadata;")
+    linkedTraceState=$(sqlite3 "$sourcePath" "SELECT linked_trace_state FROM metadata;")
+    linkedSpanId=$(sqlite3 "$sourcePath" "SELECT linked_span_id FROM metadata;")
+    echo "[Linked Span Data] linkedTraceId: $linkedTraceId, linkedTraceState: $linkedTraceState, linkedSpanId: $linkedSpanId"
+    # shellcheck disable=SC2034
+    linked_span=("$linkedTraceId" "$linkedSpanId" "$linkedTraceState")
+    otel_trace_start_parent_span cp "$sourcePath" "$destPath"
+
+    echo -e "${Green}Successfully copied ${name} to ${destPath}$Normal"
+    sqlite3 "$destPath" ".mode table" "SELECT * FROM metadata;"
+    sqlite3 "$destPath" "SELECT COUNT(*) || ' departments' FROM departments;"
+    sqlite3 "$destPath" "SELECT COUNT(*) || ' tax rates' FROM tax_rates;"
+    sqlite3 "$destPath" "SELECT COUNT(*) || ' products' FROM products;"
+    sqlite3 "$destPath" "SELECT COUNT(*) || ' product barcodes' FROM product_barcodes;"
+    sqlite3 "$destPath" "SELECT COUNT(*) || ' promotions' FROM promotions;"
+    sqlite3 "$destPath" "SELECT COUNT(*) || ' offers' FROM offers;"
+    sqlite3 "$destPath" "SELECT COUNT(*) || ' offer benefits' FROM offer_benefits;"
+    sqlite3 "$destPath" "SELECT COUNT(*) || ' offer conditions' FROM offer_conditions;"
+    sqlite3 "$destPath" "SELECT COUNT(*) || ' product ranges' FROM product_ranges;"
+    sqlite3 "$destPath" ".mode table" "ANALYZE; SELECT * FROM sqlite_stat1;"
+
+    echo -e "${Yellow}Deleting all but the latest ${FILE_RETENTION_COUNT} files from /host-data$Normal"
+    tailNum=$(( FILE_RETENTION_COUNT + 1 ))
+    cd /host-data
+    # Source: https://stackoverflow.com/a/34862475/592820
+    ls -tp | grep -v '/$' | tail -n +${tailNum} | xargs -I {} rm -- {}
+  else
+    echo -e "$Red$sourcePath has not been fully replicated from LiteFS Cloud$Normal"
+  fi
+else
+  echo -e "$Red$path does not yet exist$Normal"
+fi

docker-build-resources/etc/litefs.yml

@@ -19,4 +19,4 @@ lease:
   # and false on the replicas.
   candidate: $IS_PRIMARY
 
-exec: "bash sync.sh"
+exec: "bash watch.sh"

docker-build-resources/sync.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+
+# This script watches the LiteFS directory for changes to trigger
+# copying the synced database to the host machine.
+
+set -e
+set +v
+set +x
+
+Normal='\033[0m'
+Underline='\033[4m'
+Red='\033[0;31m'
+
+echo "Started watch.sh"
+
+if [ -z "$LITEFS_CLOUD_TOKEN" ]
+then
+  echo -e "${Red}${Underline}The LITEFS_CLOUD_TOKEN environment variable is not set! Make sure it is present in user defaults, and Bash can access them.$Normal"
+fi
+
+# Perform an initial copy attempt
+bash copy-database.sh "$DOMAIN_DB_NAME"
+
+# NOTE: We watch the internal data directory because the DB directory uses FUSE,
+# and cannot be easily monitored with fswatch.
+watched_path="$LITEFS_INTERNAL_DATA_DIRECTORY/dbs/$DOMAIN_DB_NAME/database"
+echo "Running fswatch for $watched_path"
+fswatch -or "$watched_path"  | while read f; do echo "Change detected in $f files" && bash copy-database.sh "$DOMAIN_DB_NAME"; done

docker-build-resources/watch.sh

@@ -10,7 +10,7 @@ set +x
 # otherwise, the script will fail. This is not an issue on POS machines where Docker authentication is not configured.
 export PATH="/usr/local/bin:/opt/homebrew/bin:$PATH"
 
-export VORIPOS_DOMAIN_SYNC_VERSION=0.4.1
+export VORIPOS_DOMAIN_SYNC_VERSION=0.4.2
 
 # NOTE: Bash must be given Full Disk Access in order to read the user defaults.
 #   See https://www.kith.org/jed/2022/02/15/launchctl-scheduling-shell-scripts-on-macos-and-full-disk-access/.