vai-vacuum

A tool to create VACUUM snapshots of the VAI (Virtual Aggregate Informer) database from Rancher pods.

What it does

• Opens the VAI database at /var/lib/rancher/informer_object_cache.db (read-only)
• Creates a VACUUM snapshot (compact copy) of the database
• Outputs the entire database as base64 to stdout
• All errors go to stderr prefixed with "ERROR:"

Building

CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -ldflags="-w -s" -o vai-vacuum .

This creates a static Linux binary (~6MB) that runs in Rancher pods without any dependencies.

Deployment

Do NOT commit the binary to git. Instead:

1. Build the binary using the command above
2. Create a GitHub Release in your repository
3. Upload vai-vacuum as a release asset
4. Use the release download URL in your tests

Example URL format:

https://github.com/brudnak/vai-vacuum/releases/download/v1.0.0-beta/vai-vacuum

Usage

The binary is used by VAI tests to extract database snapshots from running Rancher pods:

# Download, run, and save snapshot to a file
kubectl exec <pod> -n cattle-system -c rancher -- sh -c \
  "curl -kL -o /tmp/vai-vacuum <RELEASE-URL> && chmod +x /tmp/vai-vacuum && /tmp/vai-vacuum" \
  | base64 -d > snapshot.db

Note: The -k flag is required for curl to bypass SSL certificate verification in container environments.

Verify the snapshot

# List all tables
sqlite3 snapshot.db ".tables"

# Example output:
# *v1*Endpoints
# *v1*Event
# *v1*Namespace
# *v1*Node
# cluster.x-k8s.io_v1beta1_Machine
# management.cattle.io_v3_Cluster
# management.cattle.io_v3_FleetWorkspace
# management.cattle.io_v3_Node
# management.cattle.io_v3_Project
# management.cattle.io_v3_Setting
# provisioning.cattle.io_v1_Cluster
# ... and many more

# Check database integrity
sqlite3 snapshot.db "PRAGMA integrity_check;"

# Count rows in a specific table
sqlite3 snapshot.db "SELECT COUNT(*) FROM management.cattle.io_v3_Cluster;"

Dependencies

• modernc.org/sqlite - Pure Go SQLite driver (no CGO required)

Output Format

• Success: Raw base64 encoded database to stdout (no headers, no newlines at start)
• Failure: Error message to stderr starting with "ERROR:"

Local Testing

To test on your development machine:

1. Modify the source code for local testing

⚠️ Important: The code uses a production path that doesn't exist locally. You need to temporarily modify it.

In your Go source file, change:

const (
    vaiDBPath = "/var/lib/rancher/informer_object_cache.db"

To:

const (
    vaiDBPath = "./test.db"  // Temporary change for local testing

2. Build for your platform

# For macOS (Intel)
CGO_ENABLED=0 GOOS=darwin GOARCH=amd64 go build -ldflags="-w -s" -o vai-vacuum-mac .

# For macOS (Apple Silicon M1/M2)
CGO_ENABLED=0 GOOS=darwin GOARCH=arm64 go build -ldflags="-w -s" -o vai-vacuum-mac .

3. Test locally

# Create test database
sqlite3 test.db "CREATE TABLE test (id INTEGER); INSERT INTO test VALUES (1);"

# Run the tool
./vai-vacuum-mac | base64 -d > output.db

# Verify the output
sqlite3 output.db "SELECT * FROM test;"
# Should output: 1

4. Revert code and build for production

⚠️ Don't forget: Change the source code back to the production path:

const (
vaiDBPath = "/var/lib/rancher/informer_object_cache.db"

Then build the Linux version for deployment:

CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -ldflags="-w -s" -o vai-vacuum .

This creates the Linux binary that will run in Rancher pods.

Notes

• The tool uses SQLite's VACUUM command to create a compact copy of the database
• The snapshot is created in /tmp/vai-snapshot.db temporarily and cleaned up after encoding
• All database operations are read-only to ensure safety in production