examples/meltSnowball_dev.r

In ropenscilabs/snowball: Spin up a managed cluster and perform parallel calculations

## this code will be sent as UserData to worker nodes.
## it checks the schedule and if this machine is scheduled,
## gathers the requisite parts of the snowball and melts them
## together, runs the code, and outputs

## get/load purrr for purrr::safely
## get/load cloudyr/aws.s3 for in/out on S3
# pacman::p_load(purrr, aws.s3)
# library(purrr)
library(aws.s3)

## check that the AWS environment variable is set
if(Sys.getenv("AWS_ACCESS_KEY_ID")=="") return("NO AWS ACCESS AVAILABLE")

## bucket name that the schedule will be in
bucket <- Sys.getenv("BUCKET")
cat(paste0("bucket = ",bucket))

## this worker's instance id
instanceID <- Sys.getenv("INSTANCEID")
cat(paste0("instanceID = ",instanceID))

# ## verify that the bucket is available
# all_buckets <- bucketlist()
# cat("all_buckets = ")
# print(all_buckets)
# if (length(all_buckets)==0) bucket_exists <- FALSE
# if (length(all_buckets)==1) {
#   bucket_exists <- bucket %in% all_buckets$Name
# } else if (length(all_buckets)>1) {
#   bucket_exists <- any(bucket %in% unlist(lapply(1:length(all_buckets), function(x) all_buckets[[x]][["Name"]])))
# }
# if(!bucket_exists) return("SNOWMAN BUCKET NOT AVAILABLE")

## get the bucket as an object
snowball_bucket <- get_bucket(bucket)

# cat(paste0("bucket exists? ", bucket_exists))