Lua

Manage Cloud Storage Bucket Labels

See more Google Cloud Storage Examples

Demonstrates how to add, update, and delete labels for a Cloud Storage bucket. Lua

local chilkat = require("chilkat")

-- This example requires the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.

-- This example uses a previously obtained access token having permission for the
-- scope "https://www.googleapis.com/auth/cloud-platform"

-- In this example, Get Google Cloud Storage OAuth2 Access Token,
-- the service account access token was saved to a text file.  This example fetches the access token from the file..
local sbToken = chilkat.StringBuilder.new()
sbToken:load_file("qa_data/tokens/googleCloudStorageAccessToken.txt", "utf-8")

-- ---- Step 1
-- Create the JSON body of the PATCH request that will be sent.
-- This specifies labels to be added, updated, and/or deleted.
-- (To delete a label, set its value equal to null.)

-- {
--   "labels": {
--     "new_label_key": "new_label_value",
--     "existing_label_key": "updated_label_value",
--     "old_label_key": null
--   }
-- }

-- ---------
-- Important
-- ---------
-- You can apply multiple labels to each bucket, with a maximum of 64 labels per bucket.

--     - Keys and values cannot be longer than 63 characters each.
--     - Keys and values can only contain lowercase letters, numeric characters, underscores, and dashes. International characters are allowed.
--     - Label keys must start with a lowercase letter and international characters are allowed.
--     - Label keys cannot be empty.

-- Build JSON to update labels.
--
-- During the testing of this example, my bucket already has the following labels:
-- {
--  "labels": {
--   "test1": "xyz",
--   "test": "abc",
--   "a": "abc"
--  }
-- }

-- For this example, I'm going to add a label "b", delete the label "test1", and update
-- the label "test".
local json = chilkat.JsonObject.new()
json:update_string("labels.b", "bbb")
json:update_string("labels.test", "abc123")
json:update_null("labels.test1")

-- ---- Step 2
-- Send a PATCH equivalent to this curl command

-- curl -X PATCH --data-binary @[JSON_FILE_NAME].json \
--     -H "Authorization: Bearer [OAUTH2_TOKEN]" \
--     -H "Content-Type: application/json" \
--     "https://www.googleapis.com/storage/v1/b/[BUCKET_NAME]?fields=labels"

local http = chilkat.Http.new()
http.auth_token = sbToken:get_as_string()

http:set_url_var("bucket_name", "chilkat-ocean")
local url = "https://www.googleapis.com/storage/v1/b/{$bucket_name}?fields=labels"
local resp = chilkat.HttpResponse.new()
local success = http:http_json("PATCH", url, json, "application/json", resp)
if not success then
    print(http.last_error_text)
    return
end

local responseCode = resp.status_code
if responseCode == 401 then
    print(resp.body_str)
    print("If invalid credentials, then it is likely the access token expired.")
    print("Your app should automatically fetch a new access token and re-try.")
    return
end

-- Note: A 400 response code is likely caused by illegal characters used for a label name and/or value.

print("Response code: " .. responseCode)
print("Response body")
print(resp.body_str)

-- A response code = 200 indicates success, and the response body contains the JSON
-- for the new/updated set of labels
-- Response code: 200
-- Response body
-- {
--  "labels": {
--   "test": "abc123",
--   "a": "abc",
--   "b": "bbb"
--  }
-- }