A groovy script that will dump all Google BigQuery data to JSON files on the system local to the process

dump-all-bigquery-data.groovy

/**
 * Export and download data from Google BigQuery to Google Cloud Storage.
 *
 * @param credentialsPath The path to the JSON key file for Google Cloud authentication.
 * @param gcsBucket The Google Cloud Storage bucket name.
 * @param projectId The Google Big Query projectId.
 * @param destinationPath The path for the resulting JSON files.
 *
 * @author Chris Maggiulli (cmaggiulli@gmail.com)
 */
def exportAndDownloadFromBigQueryToGCS(credentialsPath, gcsBucket, projectId, destinationPath) {
    println("Script started at: " + new Date())

    // Load credentials from JSON key file.
    GoogleCredentials credentials
    File credentialsFile = new File(credentialsPath)

    try (FileInputStream serviceAccountStream = new FileInputStream(credentialsFile)) {
        credentials = ServiceAccountCredentials.fromStream(serviceAccountStream)
    }

    // Instantiate BigQuery client.
    BigQuery bigquery = BigQueryOptions.newBuilder()
            .setCredentials(credentials)
            .setProjectId(projectId)
            .build()
            .getService()

    // Instantiate Storage client.
    Storage storage = StorageOptions.newBuilder()
            .setCredentials(credentials)
            .setProjectId(projectId)
            .build()
            .getService()

    def format = "NEWLINE_DELIMITED_JSON"

    // Iterate through datasets in BigQuery.
    for (Dataset dataset : bigquery.listDatasets().iterateAll()) {
        println("Processing Dataset: " + dataset.getDatasetId().getDataset())

        // Iterate through tables in the dataset.
        def tables = dataset.list()
        for (Table table : tables.iterateAll()) {
            try {
                def tableName = table.getTableId().getTable()
                println("Processing Table: " + tableName)

                // Generate GCS URL for export.
                def gcsUrl = "gs://" + gcsBucket + "/" + tableName + ".json"

                // Export to GCS.
                job = table.extract(format, gcsUrl)

                try {
                    completedJob = job.waitFor(RetryOption.initialRetryDelay(Duration.ofSeconds(1)),
                            RetryOption.totalTimeout(Duration.ofMinutes(3)))

                    // Check export status.
                    if (completedJob != null && completedJob.getStatus().getError() == null) {
                        println("Table " + tableName + " successfully exported to GCS")
                    } else {
                        println("Table " + tableName + " failed to export to GCS with error: " + completedJob.getStatus().getError())
                        continue // Skip the download if export fails
                    }
                } catch (InterruptedException e) {
                    println("Error waiting for job completion: " + e)
                    continue // Skip the download if export fails
                }

                // Download from GCS.
                objectName = table.getTableId().getTable() + ".json"
                println("Downloading " + objectName + " from GCS to local directory")

                // Retrieve blob from GCS.
                blob = storage.get(BlobId.of(gcsBucket, objectName))
                newFilePath = Paths.get(destinationPath + objectName)
                tempFileTo = Files.createFile(newFilePath)

                // Download blob to local file.
                blob.downloadTo(tempFileTo)
                println("Finished downloading " + objectName)

            } catch (e) {
                println("Failed to process table " + table.getTableId().getTable() + ": " + e)
            }
        }
    }

    println("Script completed at: " + new Date())
    println("Script runtime: " + (System.currentTimeMillis() - startTime) + " milliseconds")
}

// Example usage with externalized credentials path, GCS bucket, project ID, and destination path.
def credentialsPath = "./fake-credentials.json"
def gcsBucket = "fake-bucket-name"
def projectId = "fakeprojectid-131113"
def destinationPath = "./"
def startTime = System.currentTimeMillis()
exportAndDownloadFromBigQueryToGCS(credentialsPath, gcsBucket, projectId, destinationPath)

Jenkinsfile

pipeline {
    agent any

    environment {
        CREDENTIALS_PATH = './fake-credentials.json'
        GCS_BUCKET = 'fake-bucket-name'
        PROJECT_ID = 'fakeprojectid-131113'
        DESTINATION_PATH = './'
    }

    stages {
        stage('Execute Script') {
            steps {
                script {
                    def startTime = System.currentTimeMillis()

                    echo "Script started at: ${currentBuild.startTimeInMillis}"
                    // Calling the externalized function
                    exportAndDownloadFromBigQueryToGCS(CREDENTIALS_PATH, GCS_BUCKET, PROJECT_ID, DESTINATION_PATH)

                    echo "Script completed at: ${currentBuild.startTimeInMillis}"
                    echo "Script runtime: ${System.currentTimeMillis() - startTime} milliseconds"
                }
            }
        }
    }
}

def exportAndDownloadFromBigQueryToGCS(credentialsPath, gcsBucket, projectId, destinationPath) {
    // The actual script content (excluding imports and initial print statements)
    GoogleCredentials credentials
    File credentialsFile = new File(credentialsPath)

    try (FileInputStream serviceAccountStream = new FileInputStream(credentialsFile)) {
        credentials = ServiceAccountCredentials.fromStream(serviceAccountStream)
    }

    BigQuery bigquery = BigQueryOptions.newBuilder()
            .setCredentials(credentials)
            .setProjectId(projectId)
            .build()
            .getService()

    Storage storage = StorageOptions.newBuilder()
            .setCredentials(credentials)
            .setProjectId(projectId)
            .build()
            .getService()

    def format = "NEWLINE_DELIMITED_JSON"

    for (Dataset dataset : bigquery.listDatasets().iterateAll()) {
        echo "Processing Dataset: ${dataset.getDatasetId().getDataset()}"

        def tables = dataset.list()
        for (Table table : tables.iterateAll()) {
            try {
                def tableName = table.getTableId().getTable()
                echo "Processing Table: ${tableName}"

                def gcsUrl = "gs://${gcsBucket}/${tableName}.json"

                job = table.extract(format, gcsUrl)

                try {
                    completedJob = job.waitFor(RetryOption.initialRetryDelay(Duration.ofSeconds(1)),
                            RetryOption.totalTimeout(Duration.ofMinutes(3)))

                    if (completedJob != null && completedJob.getStatus().getError() == null) {
                        echo "Table ${tableName} successfully exported to GCS"
                    } else {
                        echo "Table ${tableName} failed to export to GCS with error: ${completedJob.getStatus().getError()}"
                        continue
                    }
                } catch (InterruptedException e) {
                    echo "Error waiting for job completion: ${e}"
                    continue
                }

                objectName = "${table.getTableId().getTable()}.json"
                echo "Downloading ${objectName} from GCS to local directory"

                blob = storage.get(BlobId.of(gcsBucket, objectName))
                newFilePath = Paths.get("${destinationPath}/${objectName}")
                tempFileTo = Files.createFile(newFilePath)

                blob.downloadTo(tempFileTo)
                echo "Finished downloading ${objectName}"

            } catch (e) {
                echo "Failed to process table ${table.getTableId().getTable()}: ${e}"
            }
        }
    }
}