(Perl) Get Object MetaData from Google Cloud Storage

Demonstrates how to download a Google Cloud Storage object's metadata.

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use 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..
$sbToken = chilkat::CkStringBuilder->new();
$sbToken->LoadFile("qa_data/tokens/googleCloudStorageAccessToken.txt","utf-8");

# Send a GET equivalent to this curl command.

# curl -X GET \
#     -H "Authorization: Bearer [OAUTH2_TOKEN]" \
#     -o "[SAVE_TO_LOCATION]" \
#     "https://www.googleapis.com/storage/v1/b/[BUCKET_NAME]/o/[OBJECT_NAME]?projection=full"

$http = chilkat::CkHttp->new();

$http->put_AuthToken($sbToken->getAsString());

# Construct a URL to download the metadata for the object named "starfish.jpg" located in the "chilkat-ocean" bucket.
$http->SetUrlVar("bucket_name","chilkat-ocean");
$http->SetUrlVar("object_name","starfish.jpg");
$url = "https://www.googleapis.com/storage/v1/b/{$bucket_name}/o/{$object_name}?projection=full";

# If there is an error response, then we didn't actually download the metadata,
# but instead we downloaded an error response..
$sbMetaData = chilkat::CkStringBuilder->new();
$success = $http->DownloadSb($url,"utf-8",$sbMetaData);
if ($success == 0) {
    print $http->lastErrorText() . "\r\n";
    exit;
}

$responseCode = $http->get_LastStatus();
if ($responseCode == 401) {
    print "If invalid credentials, then it is likely the access token expired." . "\r\n";
    print "Your app should automatically fetch a new access token and re-try." . "\r\n";
}

if ($responseCode != 200) {
    print "Error response code = " . $responseCode . "\r\n";
    print "Error:" . "\r\n";
    print $sbMetaData->getAsString() . "\r\n";
    exit;
}

print $sbMetaData->getAsString() . "\r\n";
print "Success." . "\r\n";

# Sample output:

# {
#  "kind": "storage#object",
#  "id": "chilkat-ocean/starfish.jpg/1502670320090292",
#  "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg",
#  "name": "starfish.jpg",
#  "bucket": "chilkat-ocean",
#  "generation": "1502670320090292",
#  "metageneration": "1",
#  "contentType": "image/jpeg",
#  "timeCreated": "2017-08-14T00:25:20.040Z",
#  "updated": "2017-08-14T00:25:20.040Z",
#  "storageClass": "MULTI_REGIONAL",
#  "timeStorageClassUpdated": "2017-08-14T00:25:20.040Z",
#  "size": "6229",
#  "md5Hash": "LpxZ2/JmI2fcl9/dqF2gSA==",
#  "mediaLink": "https://www.googleapis.com/download/storage/v1/b/chilkat-ocean/o/starfish.jpg?generation=1502670320090292&alt=media",
#  "acl": [
#   {
#    "kind": "storage#objectAccessControl",
#    "id": "chilkat-ocean/starfish.jpg/1502670320090292/project-owners-933037264567",
#    "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg/acl/project-owners-933037264567",
#    "bucket": "chilkat-ocean",
#    "object": "starfish.jpg",
#    "generation": "1502670320090292",
#    "entity": "project-owners-933037264567",
#    "role": "OWNER",
#    "projectTeam": {
#     "projectNumber": "933037264567",
#     "team": "owners"
#    },
#    "etag": "CLT5kpW71dUCEAE="
#   },
#   {
#    "kind": "storage#objectAccessControl",
#    "id": "chilkat-ocean/starfish.jpg/1502670320090292/project-editors-933037264567",
#    "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg/acl/project-editors-933037264567",
#    "bucket": "chilkat-ocean",
#    "object": "starfish.jpg",
#    "generation": "1502670320090292",
#    "entity": "project-editors-933037264567",
#    "role": "OWNER",
#    "projectTeam": {
#     "projectNumber": "933037264567",
#     "team": "editors"
#    },
#    "etag": "CLT5kpW71dUCEAE="
#   },
#   {
#    "kind": "storage#objectAccessControl",
#    "id": "chilkat-ocean/starfish.jpg/1502670320090292/project-viewers-933037264567",
#    "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg/acl/project-viewers-933037264567",
#    "bucket": "chilkat-ocean",
#    "object": "starfish.jpg",
#    "generation": "1502670320090292",
#    "entity": "project-viewers-933037264567",
#    "role": "READER",
#    "projectTeam": {
#     "projectNumber": "933037264567",
#     "team": "viewers"
#    },
#    "etag": "CLT5kpW71dUCEAE="
#   },
#   {
#    "kind": "storage#objectAccessControl",
#    "id": "chilkat-ocean/starfish.jpg/1502670320090292/user-starfish@chilkat-176611.iam.gserviceaccount.com",
#    "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg/acl/user-starfish@chilkat-176611.iam.gserviceaccount.com",
#    "bucket": "chilkat-ocean",
#    "object": "starfish.jpg",
#    "generation": "1502670320090292",
#    "entity": "user-starfish@chilkat-176611.iam.gserviceaccount.com",
#    "role": "OWNER",
#    "email": "starfish@chilkat-176611.iam.gserviceaccount.com",
#    "etag": "CLT5kpW71dUCEAE="
#   }
#  ],
#  "owner": {
#   "entity": "user-starfish@chilkat-176611.iam.gserviceaccount.com"
#  },
#  "crc32c": "9RjgwQ==",
#  "etag": "CLT5kpW71dUCEAE="
# }
#