getting URLs from azure

[mdsumner]

## get a token
sas_base <- function() {
  "https://planetarycomputer.microsoft.com/api/sas/v1/token"
}
sas_account_container <- function(account, container = NULL) {
  file.path(sas_base(), account, container)
}
sas_collectionid <- function(collection_id) {
  file.path(sas_base(), collection_id)
}
sas <- function(id) {
  if (grepl("/", id)) {
   uri <- sas_account_container(id) 
  } else {
   uri <- sas_collectionid(id)
  }
 #{collection_id} 
 #{storage_account}/{container}
 readLines(uri, warn = FALSE)
}

pc_sas_token <- function(id) {
  x <- sas(id)
  jsonlite::fromJSON(x)$token
}

pcstacitem <- function(item, asset) {
  glue::glue("/vsicurl/https://pcstacitems.blob.core.windows.net/items/{asset}?{pc_sas_token(item)}")
}
pcstacitem("io-lulc-9-class", "io-lulc-9-class.parquet")