C SDK log storage - Object Storage Service - Alibaba Cloud Documentation Center

Accessing OSS generates many access logs. You can use the log storage feature to save these logs to a specified bucket. The logs are generated as hourly files and follow a fixed naming convention.

Notes

The log storage feature is supported in OSS C SDK 3.6.0 and later.

In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS from other Alibaba Cloud services in the same region as OSS, use an internal endpoint. For more information about OSS regions and endpoints, see Regions and endpoints.
In this topic, an OSSClient instance is created by using an OSS endpoint. If you want to create an OSSClient instance by using custom domain names or Security Token Service (STS), see Initialization.
To enable log storage, you must have the oss:PutBucketLogging permission. To view a log storage configuration, you must have the oss:GetBucketLogging permission. To disable log storage, you must have the oss:DeleteBucketLogging permission. For more information, see Grant custom access policies to RAM users.

Enable log storage

The following code shows how to enable the log storage feature.

#include "oss_api.h"
#include "aos_http_io.h"
/* Set yourEndpoint to the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
const char *endpoint = "yourEndpoint";
/* Specify the bucket name. For example, examplebucket. */
const char *bucket_name = "examplebucket";
/* Specify the destination bucket to store the log files. The targetBucketName and bucketName can be the same or different. */
const char *target_bucket_name = "yourTargetBucketName";
/* Set the folder where the log files are stored. If you specify this parameter, the log files are saved to the specified folder in the destination bucket. If you do not specify this parameter, the log files are saved to the root directory of the destination bucket. */
const char *target_logging_prefix = "yourTargetPrefix";
/* Set yourRegion to the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou. */
const char *region = "yourRegion";
void init_options(oss_request_options_t *options)
{
    options->config = oss_config_create(options->pool);
    /* Initialize the aos_string_t type with a char* string. */
    aos_str_set(&options->config->endpoint, endpoint);
    /* Obtain access credentials from environment variables. Before you run this sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set. */
    aos_str_set(&options->config->access_key_id, getenv("OSS_ACCESS_KEY_ID"));
    aos_str_set(&options->config->access_key_secret, getenv("OSS_ACCESS_KEY_SECRET"));
    // You must also configure the following two parameters.
    aos_str_set(&options->config->region, region);
    options->config->signature_version = 4;
    /* Specify whether a CNAME is used. A value of 0 indicates that no CNAME is used. */
    options->config->is_cname = 0;
    /* Set network parameters, such as the timeout period. */
    options->ctl = aos_http_controller_create(options->pool, 0);
}
int main(int argc, char *argv[])
{
    /* Call the aos_http_io_initialize method at the program entry to initialize global resources such as the network and memory. */
    if (aos_http_io_initialize(NULL, 0) != AOSE_OK) {
        exit(1);
    }
    /* The memory pool (pool) for memory management is equivalent to apr_pool_t. The implementation code is in the apr library. */
    aos_pool_t *pool;
    /* Create a memory pool. The second parameter is NULL, which indicates that the memory pool does not inherit from another memory pool. */
    aos_pool_create(&pool, NULL);
    /* Create and initialize options. This parameter includes global configuration information such as the endpoint, access_key_id, access_key_secret, is_cname, and curl. */
    oss_request_options_t *oss_client_options;
    /* Allocate memory to options in the memory pool. */
    oss_client_options = oss_request_options_create(pool);
    /* Initialize the client options oss_client_options. */
    init_options(oss_client_options);
    /* Initialize parameters. */
    aos_string_t bucket;
    oss_logging_config_content_t *content;
    aos_table_t *resp_headers = NULL; 
    aos_status_t *resp_status = NULL; 
    aos_str_set(&bucket, bucket_name);
    content = oss_create_logging_rule_content(pool);
    aos_str_set(&content->target_bucket, target_bucket_name);
    aos_str_set(&content->prefix, target_logging_prefix);
    /* Enable access logging for the bucket. */
    resp_status = oss_put_bucket_logging(oss_client_options, &bucket, content, &resp_headers);
    if (aos_status_is_ok(resp_status)) {
        printf("put bucket logging succeeded\n");
    } else {
        printf("put bucket logging failed, code:%d, error_code:%s, error_msg:%s, request_id:%s\n",
            resp_status->code, resp_status->error_code, resp_status->error_msg, resp_status->req_id); 
    }
    /* Release the memory pool. This releases the memory allocated to resources during the request. */
    aos_pool_destroy(pool);
    /* Release the previously allocated global resources. */
    aos_http_io_deinitialize();
    return 0;
}

View the log storage configuration

The following code shows how to view the log storage configuration.

#include "oss_api.h"
#include "aos_http_io.h"
/* Set yourEndpoint to the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
const char *endpoint = "yourEndpoint";
/* Specify the bucket name. For example, examplebucket. */
const char *bucket_name = "examplebucket";
/* Set yourRegion to the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou. */
const char *region = "yourRegion";
void init_options(oss_request_options_t *options)
{
    options->config = oss_config_create(options->pool);
    /* Initialize the aos_string_t type with a char* string. */
    aos_str_set(&options->config->endpoint, endpoint);
    /* Obtain access credentials from environment variables. Before you run this sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set. */
    aos_str_set(&options->config->access_key_id, getenv("OSS_ACCESS_KEY_ID"));
    aos_str_set(&options->config->access_key_secret, getenv("OSS_ACCESS_KEY_SECRET"));
    // You must also configure the following two parameters.
    aos_str_set(&options->config->region, region);
    options->config->signature_version = 4;
    /* Specify whether a CNAME is used. A value of 0 indicates that no CNAME is used. */
    options->config->is_cname = 0;
    /* Set network parameters, such as the timeout period. */
    options->ctl = aos_http_controller_create(options->pool, 0);
}
int main(int argc, char *argv[])
{
    /* Call the aos_http_io_initialize method at the program entry to initialize global resources such as the network and memory. */
    if (aos_http_io_initialize(NULL, 0) != AOSE_OK) {
        exit(1);
    }
    /* The memory pool (pool) for memory management is equivalent to apr_pool_t. The implementation code is in the apr library. */
    aos_pool_t *pool;
    /* Create a memory pool. The second parameter is NULL, which indicates that the memory pool does not inherit from another memory pool. */
    aos_pool_create(&pool, NULL);
    /* Create and initialize options. This parameter includes global configuration information such as the endpoint, access_key_id, access_key_secret, is_cname, and curl. */
    oss_request_options_t *oss_client_options;
    /* Allocate memory to options in the memory pool. */
    oss_client_options = oss_request_options_create(pool);
    /* Initialize the client options oss_client_options. */
    init_options(oss_client_options);
    /* Initialize parameters. */
    aos_string_t bucket;
    oss_logging_config_content_t *content;
    aos_table_t *resp_headers = NULL; 
    aos_status_t *resp_status = NULL; 
    aos_str_set(&bucket, bucket_name);
    content = oss_create_logging_rule_content(pool);
    /* View the access logging settings of the bucket. */
    resp_status = oss_get_bucket_logging(oss_client_options, &bucket, content, &resp_headers);
    if (aos_status_is_ok(resp_status)) {
        printf("get bucket logging succeeded\n");
    } else {
        printf("get bucket logging failed, code:%d, error_code:%s, error_msg:%s, request_id:%s\n",
            resp_status->code, resp_status->error_code, resp_status->error_msg, resp_status->req_id);
    }
    printf("bucket:%s, prefix:%s\n", content->target_bucket.data, content->prefix.data);
    /* Release the memory pool. This releases the memory allocated to resources during the request. */
    aos_pool_destroy(pool);
    /* Release the previously allocated global resources. */
    aos_http_io_deinitialize();
    return 0;
}

Disable log storage

The following code shows how to disable the log storage feature.

#include "oss_api.h"
#include "aos_http_io.h"
/* Set yourEndpoint to the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
const char *endpoint = "yourEndpoint";
/* Specify the bucket name. For example, examplebucket. */
const char *bucket_name = "examplebucket";
/* Set yourRegion to the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou. */
const char *region = "yourRegion";
void init_options(oss_request_options_t *options)
{
    options->config = oss_config_create(options->pool);
    /* Initialize the aos_string_t type with a char* string. */
    aos_str_set(&options->config->endpoint, endpoint);
    /* Obtain access credentials from environment variables. Before you run this sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set. */
    aos_str_set(&options->config->access_key_id, getenv("OSS_ACCESS_KEY_ID"));
    aos_str_set(&options->config->access_key_secret, getenv("OSS_ACCESS_KEY_SECRET"));
    // You must also configure the following two parameters.
    aos_str_set(&options->config->region, region);
    options->config->signature_version = 4;
    /* Specify whether a CNAME is used. A value of 0 indicates that no CNAME is used. */
    options->config->is_cname = 0;
    /* Set network parameters, such as the timeout period. */
    options->ctl = aos_http_controller_create(options->pool, 0);
}
int main(int argc, char *argv[])
{
    /* Call the aos_http_io_initialize method at the program entry to initialize global resources such as the network and memory. */
    if (aos_http_io_initialize(NULL, 0) != AOSE_OK) {
        exit(1);
    }
    /* The memory pool (pool) for memory management is equivalent to apr_pool_t. The implementation code is in the apr library. */
    aos_pool_t *pool;
    /* Create a memory pool. The second parameter is NULL, which indicates that the memory pool does not inherit from another memory pool. */
    aos_pool_create(&pool, NULL);
    /* Create and initialize options. This parameter includes global configuration information such as the endpoint, access_key_id, access_key_secret, is_cname, and curl. */
    oss_request_options_t *oss_client_options;
    /* Allocate memory to options in the memory pool. */
    oss_client_options = oss_request_options_create(pool);
    /* Initialize the client options oss_client_options. */
    init_options(oss_client_options);
    /* Initialize parameters. */
    aos_string_t bucket;
    aos_table_t *resp_headers = NULL; 
    aos_status_t *resp_status = NULL; 
    aos_str_set(&bucket, bucket_name);
    /* Disable access logging. */
    resp_status = oss_delete_bucket_logging(oss_client_options, &bucket, &resp_headers);
    if (aos_status_is_ok(resp_status)) {
        printf("delete bucket logging succeeded\n");
    } else {
        printf("delete bucket logging failed, code:%d, error_code:%s, error_msg:%s, request_id:%s\n",
            resp_status->code, resp_status->error_code, resp_status->error_msg, resp_status->req_id);
    }
    /* Release the memory pool. This releases the memory allocated to resources during the request. */
    aos_pool_destroy(pool);
    /* Release the previously allocated global resources. */
    aos_http_io_deinitialize();
    return 0;
}

References

For more information, see PutBucketLogging.
For more information, see GetBucketLogging.
For more information, see DeleteBucketLogging.