samples/sas_resource_files/sas_resources_files_example.R

In Azure/doAzureParallel: doAzureParallel

library(doAzureParallel)

doAzureParallel::setCredentials("credentials.json")
# Using rAzureBatch directly for storage uploads
config <- rjson::fromJSON(file = paste0("credentials.json"))

storageCredentials <- rAzureBatch::SharedKeyCredentials$new(
  name = config$sharedKey$storageAccount$name,
  key = config$sharedKey$storageAccount$key
)

storageAccountName <- storageCredentials$name
inputContainerName <- "datasets"

storageClient <- rAzureBatch::StorageServiceClient$new(
  authentication = storageCredentials,
  url = sprintf("https://%s.blob.%s",
               storageCredentials$name,
               config$sharedKey$storageAccount$endpointSuffix
               )
)

# Generate a sas tokens with the createSasToken function
# Write-only SAS. Will be used for uploading files to storage.
writeSasToken <- storageClient$generateSasToken(permission = "w", "c", path = inputContainerName)

# Read-only SAS. Will be used for downloading files from storage.
readSasToken <- storageClient$generateSasToken(permission = "r", "c", path = inputContainerName)

# Create a Storage container in the Azure Storage account
storageClient$containerOperations$createContainer(inputContainerName, content = "response")

# Upload blobs with a write sasToken
storageClient$blobOperations$uploadBlob(inputContainerName,
                                        fileDirectory = "1989.csv",
                                        sasToken = writeSasToken,
                                        accountName = storageAccountName)

storageClient$blobOperations$uploadBlob(inputContainerName,
                                        fileDirectory = "1990.csv",
                                        sasToken = writeSasToken,
                                        accountName = storageAccountName)

# Create URL paths with read-only permissions
csvFileUrl1 <- rAzureBatch::createBlobUrl(storageAccount = storageAccountName,
              containerName = inputContainerName,
              sasToken = readSasToken,
              fileName = "1989.csv")


csvFileUrl2 <- rAzureBatch::createBlobUrl(storageAccount = storageAccountName,
                             containerName = inputContainerName,
                             sasToken = readSasToken,
                             fileName = "1990.csv")

# Create a list of files to download to the cluster using read-only permissions
# Place the files in a directory called 'data'
resource_files = list(
  rAzureBatch::createResourceFile(httpUrl = csvFileUrl1, filePath = "data/1989.csv"),
  rAzureBatch::createResourceFile(httpUrl = csvFileUrl2, filePath = "data/1990.csv")
)

# Create the cluster
cluster <- makeCluster("sas_resource_files_cluster.json", resourceFiles = resource_files)
registerDoAzureParallel(cluster)
workers <- getDoParWorkers()

# Files downloaded to the cluster are placed in a specific directory on each node called 'wd'
# Use the pre-defined environment variable 'AZ_BATCH_NODE_STARTUP_DIR' to find the path to the directory
listFiles <- foreach(i = 1:workers, .combine='rbind') %dopar% {
  fileDirectory <- paste0(Sys.getenv("AZ_BATCH_NODE_STARTUP_DIR"), "/wd", "/data")
  files <- list.files(fileDirectory)
  df = data.frame("node" = i, "files" = files)
  return(df)
}

# List the files downloaded to each node in the cluster
listFiles

stopCluster(cluster)