Bucket access log formatting in Amazon Lightsail
Access logging provides detailed records for the requests that are made to a bucket in the Amazon Lightsail object storage service. You can use access logs for security and access audits, or learn about your customer base. This section describes the format and other details about access log files. For more information about logging basics, see Bucket access logs.
Access log files consist of a sequence of newline-delimited log records. Each log record represents one request and consists of space-delimited fields.
The following is an example log consisting of five log records.
79a59df900b949e55d96a1e698fbacedfd6e09d98eacf8f8d5218e7cd47ef2be awsexamplebucket1 [06/Feb/2019:00:00:38 +0000] 192.0.2.3 79a59df900b949e55d96a1e698fbacedfd6e09d98eacf8f8d5218e7cd47ef2be 3E57427F3EXAMPLE REST.GET.VERSIONING - "GET /awsexamplebucket1?versioning HTTP/1.1" 200 - 113 - 7 - "-" "S3Console/0.4" - s9lzHYrFp76ZVxRcpX9+5cjAnEH2ROuNkd2BHfIa6UkFVdtjf5mKR3/eTPFvsiP/XV/VLi31234= SigV2 ECDHE-RSA-AES128-GCM-SHA256 AuthHeader awsexamplebucket1.s3.us-west-1.amazonaws.com TLSV1.1
79a59df900b949e55d96a1e698fbacedfd6e09d98eacf8f8d5218e7cd47ef2be awsexamplebucket1 [06/Feb/2019:00:00:38 +0000] 192.0.2.3 79a59df900b949e55d96a1e698fbacedfd6e09d98eacf8f8d5218e7cd47ef2be 891CE47D2EXAMPLE REST.GET.LOGGING_STATUS - "GET /awsexamplebucket1?logging HTTP/1.1" 200 - 242 - 11 - "-" "S3Console/0.4" - 9vKBE6vMhrNiWHZmb2L0mXOcqPGzQOI5XLnCtZNPxev+Hf+7tpT6sxDwDty4LHBUOZJG96N1234= SigV2 ECDHE-RSA-AES128-GCM-SHA256 AuthHeader awsexamplebucket1.s3.us-west-1.amazonaws.com TLSV1.1
79a59df900b949e55d96a1e698fbacedfd6e09d98eacf8f8d5218e7cd47ef2be awsexamplebucket1 [06/Feb/2019:00:00:38 +0000] 192.0.2.3 79a59df900b949e55d96a1e698fbacedfd6e09d98eacf8f8d5218e7cd47ef2be A1206F460EXAMPLE REST.GET.BUCKETPOLICY - "GET /awsexamplebucket1?policy HTTP/1.1" 404 NoSuchBucketPolicy 297 - 38 - "-" "S3Console/0.4" - BNaBsXZQQDbssi6xMBdBU2sLt+Yf5kZDmeBUP35sFoKa3sLLeMC78iwEIWxs99CRUrbS4n11234= SigV2 ECDHE-RSA-AES128-GCM-SHA256 AuthHeader awsexamplebucket1.s3.us-west-1.amazonaws.com TLSV1.1
79a59df900b949e55d96a1e698fbacedfd6e09d98eacf8f8d5218e7cd47ef2be awsexamplebucket1 [06/Feb/2019:00:01:00 +0000] 192.0.2.3 79a59df900b949e55d96a1e698fbacedfd6e09d98eacf8f8d5218e7cd47ef2be 7B4A0FABBEXAMPLE REST.GET.VERSIONING - "GET /awsexamplebucket1?versioning HTTP/1.1" 200 - 113 - 33 - "-" "S3Console/0.4" - Ke1bUcazaN1jWuUlPJaxF64cQVpUEhoZKEG/hmy/gijN/I1DeWqDfFvnpybfEseEME/u7ME1234= SigV2 ECDHE-RSA-AES128-GCM-SHA256 AuthHeader awsexamplebucket1.s3.us-west-1.amazonaws.com TLSV1.1
79a59df900b949e55d96a1e698fbacedfd6e09d98eacf8f8d5218e7cd47ef2be awsexamplebucket1 [06/Feb/2019:00:01:57 +0000] 192.0.2.3 79a59df900b949e55d96a1e698fbacedfd6e09d98eacf8f8d5218e7cd47ef2be DD6CC733AEXAMPLE REST.PUT.OBJECT s3-dg.pdf "PUT /awsexamplebucket1/s3-dg.pdf HTTP/1.1" 200 - - 4406583 41754 28 "-" "S3Console/0.4" - 10S62Zv81kBW7BB6SX4XJ48o6kpcl6LPwEoizZQQxJd5qDSCTLX0TgS37kYUBKQW3+bPdrg1234= SigV4 ECDHE-RSA-AES128-SHA AuthHeader awsexamplebucket1.s3.us-west-1.amazonaws.com TLSV1.1
Note
Any log record field can be set to – (dash) to indicate that the data was
unknown or unavailable, or that the field was not applicable to the request.
Contents
Log record fields
The following list describes the log record fields.
Access Point ARN (Amazon Resource Name)
The Amazon Resource Name (ARN) of the access point of the request. If access point ARN is malformed or not used, the field will contain a '-'. For more information on access points, see Using access points. For more information on ARNs, see the topic on Amazon Resource Name (ARN) in the AWS General Reference.
Example entry
arn:aws:s3:us-east-1:123456789012:accesspoint/example-AP
Bucket Owner
The canonical user ID of the owner of the source bucket. The canonical user ID is another form of the AWS account ID. For more information about the canonical user ID, see AWS account identifiers in the AWS General Reference. For information about how to find the canonical user ID for your account, see Finding the canonical user ID for your AWS account.
Example entry
79a59df900b949e55d96a1e698fbacedfd6e09d98eacf8f8d5218e7cd47ef2be
Bucket
The name of the bucket that the request was processed against. If the system receives a malformed request and cannot determine the bucket, the request will not appear in any access log.
Example entry
awsexamplebucket1
Time
The time at which the request was received; these dates and times are in Coordinated
Universal Time (UTC). The format, using strftime() terminology, is
as follows: [%d/%b/%Y:%H:%M:%S %z]
Example entry
[06/Feb/2019:00:00:38 +0000]
Remote IP
The apparent internet address of the requester. Intermediate proxies and firewalls might obscure the actual address of the machine making the request.
Example entry
192.0.2.3
Requester
The canonical user ID of the requester, or a - for unauthenticated requests.
If the requester was an IAM user, this field returns the requester's IAM user name along with
the AWS root account that the IAM user belongs to. This identifier is the same one used for
access control purposes.
Example entry
79a59df900b949e55d96a1e698fbacedfd6e09d98eacf8f8d5218e7cd47ef2be
Request ID
A string generated by Lightsail to uniquely identify each request.
Example entry
3E57427F33A59F07
Operation
The operation listed here is declared as
SOAP.,
operationREST.,
HTTP_method.resource_typeWEBSITE., or
HTTP_method.resource_typeBATCH.DELETE.OBJECT.
Example entry
REST.PUT.OBJECT
Key
The "key" part of the request, URL encoded, or "-" if the operation does not take a key parameter.
Example entry
/photos/2019/08/puppy.jpg
Request-URI
The Request-URI part of the HTTP request message.
Example Entry
"GET /awsexamplebucket1/photos/2019/08/puppy.jpg?x-foo=bar HTTP/1.1"
HTTP status
The numeric HTTP status code of the response.
Example entry
200
Error Code
The Amazon S3 Error code, or "-" if no error occurred.
Example entry
NoSuchBucket
Bytes Sent
The number of response bytes sent, excluding HTTP protocol overhead, or "-" if zero.
Example entry
2662992
Object Size
The total size of the object in question.
Example entry
3462992
Total Time
The number of milliseconds the request was in flight from the bucket's perspective. This value is measured from the time your request is received to the time that the last byte of the response is sent. Measurements made from the client's perspective might be longer due to network latency.
Example entry
70
Turn-Around Time
The number of milliseconds that Lightsail spent processing your request. This value is measured from the time the last byte of your request was received until the time the first byte of the response was sent.
Example entry
10
Referer
The value of the HTTP Referer header, if present. HTTP user-agents (for example, browsers) typically set this header to the URL of the linking or embedding page when making a request.
Example entry
"http://www.amazon.com/webservices"
User-Agent
The value of the HTTP User-Agent header.
Example entry
"curl/7.15.1"
Version Id
The version ID in the request, or - if the operation does not take a
versionId parameter.
Example entry
3HL4kqtJvjVBH40Nrjfkd
Host Id
The x-amz-id-2 or Lightsail extended request ID.
Example entry
s9lzHYrFp76ZVxRcpX9+5cjAnEH2ROuNkd2BHfIa6UkFVdtjf5mKR3/eTPFvsiP/XV/VLi31234=
Signature Version
The signature version, SigV2 or SigV4, that was used to
authenticate the request or a - for unauthenticated requests.
Example entry
SigV2
Cipher Suite
The Secure Sockets Layer (SSL) cipher that was negotiated for HTTPS request or a
- for HTTP.
Example entry
ECDHE-RSA-AES128-GCM-SHA256
Authentication Type
The type of request authentication used, AuthHeader for authentication
headers, QueryString for query string (pre-signed URL) or a - for
unauthenticated requests.
Example entry
AuthHeader
Host Header
The endpoint used to connect to Lightsail.
Example entry
s3.us-west-2.amazonaws.com
TLS version
The Transport Layer Security (TLS) version negotiated by the client. The value is one of
following: TLSv1, TLSv1.1, TLSv1.2; or -
if TLS wasn't used.
Example entry
TLSv1.2
Additional logging for copy operations
A copy operation involves a GET and a PUT. For that reason, we
log two records when performing a copy operation. The previous section describes the fields
related to the PUT part of the operation. The following list describes the fields
in the record that relate to the GET part of the copy operation.
Bucket Owner
The canonical user ID of the bucket that stores the object being copied. The canonical user ID is another form of the AWS account ID. For more information about the canonical user ID, see AWS account identifiers in the AWS General Reference. For information about how to find the canonical user ID for your account, see Finding the canonical user ID for your AWS account.
Example entry
79a59df900b949e55d96a1e698fbacedfd6e09d98eacf8f8d5218e7cd47ef2be
Bucket
The name of the bucket that stores the object being copied.
Example entry
awsexamplebucket1
Time
The time at which the request was received; these dates and times are in Coordinated
Universal time (UTC). The format, using strftime() terminology, is as follows:
[%d/%B/%Y:%H:%M:%S %z]
Example entry
[06/Feb/2019:00:00:38 +0000]
Remote IP
The apparent internet address of the requester. Intermediate proxies and firewalls might obscure the actual address of the machine making the request.
Example entry
192.0.2.3
Requester
The canonical user ID of the requester, or a - for unauthenticated requests.
If the requester was an IAM user, this field will return the requester's IAM user name along
with the AWS root account that the IAM user belongs to. This identifier is the same one used
for access control purposes.
Example entry
79a59df900b949e55d96a1e698fbacedfd6e09d98eacf8f8d5218e7cd47ef2be
Request ID
A string generated by Lightsail to uniquely identify each request.
Example entry
3E57427F33A59F07
Operation
The operation listed here is declared as
SOAP.,
operationREST.,
HTTP_method.resource_typeWEBSITE., or
HTTP_method.resource_typeBATCH.DELETE.OBJECT.
Example entry
REST.COPY.OBJECT_GET
Key
The "key" of the object being copied or "-" if the operation does not take a key parameter.
Example entry
/photos/2019/08/puppy.jpg
Request-URI
The Request-URI part of the HTTP request message.
Example entry
"GET /awsexamplebucket1/photos/2019/08/puppy.jpg?x-foo=bar"
HTTP status
The numeric HTTP status code of the GET portion of the copy operation.
Example entry
200
Error Code
The Amazon S3 Error code, of the GET portion of the copy operation or
- if no error occurred.
Example entry
NoSuchBucket
Bytes Sent
The number of response bytes sent, excluding HTTP protocol overhead, or "-" if zero.
Example entry
2662992
Object Size
The total size of the object in question.
Example entry
3462992
Total Time
The number of milliseconds the request was in flight from the bucket's perspective. This value is measured from the time your request is received to the time that the last byte of the response is sent. Measurements made from the client's perspective might be longer due to network latency.
Example entry
70
Turn-Around Time
The number of milliseconds that Lightsail spent processing your request. This value is measured from the time the last byte of your request was received until the time the first byte of the response was sent.
Example entry
10
Referer
The value of the HTTP Referer header, if present. HTTP user-agents (for example, browsers) typically set this header to the URL of the linking or embedding page when making a request.
Example entry
"http://www.amazon.com/webservices"
User-Agent
The value of the HTTP User-Agent header.
Example entry
"curl/7.15.1"
Version Id
The version ID of the object being copied or - if the
x-amz-copy-source header didn’t specify a versionId parameter as
part of the copy source.
Example entry
3HL4kqtJvjVBH40Nrjfkd
Host Id
The x-amz-id-2 or Lightsail extended request ID.
Example entry
s9lzHYrFp76ZVxRcpX9+5cjAnEH2ROuNkd2BHfIa6UkFVdtjf5mKR3/eTPFvsiP/XV/VLi31234=
Signature Version
The signature version, SigV2 or SigV4, that was used to
authenticate the request or a - for unauthenticated requests.
Example entry
SigV2
Cipher Suite
The Secure Sockets Layer (SSL) cipher that was negotiated for HTTPS request or a
- for HTTP.
Example entry
ECDHE-RSA-AES128-GCM-SHA256
Authentication Type
The type of request authentication used, AuthHeader for authentication
headers, QueryString for query string (presigned URL) or a - for
unauthenticated requests.
Example entry
AuthHeader
Host Header
The endpoint used to connect to Lightsail.
Example entry
s3.us-west-2.amazonaws.com
TLS version
The Transport Layer Security (TLS) version negotiated by the client. The value is one of
following: TLSv1, TLSv1.1, TLSv1.2; or -
if TLS wasn't used.
Example entry
TLSv1.2
Custom access log information
You can include custom information to be stored in the access log record for a request. To
do this, add a custom query-string parameter to the URL for the request. Lightsail ignores
query-string parameters that begin with "x-", but includes those parameters in the access log
record for the request, as part of the Request-URI field of the log
record.
For example, a GET request for
"s3.amazonaws.com/awsexamplebucket1/photos/2019/08/puppy.jpg?x-user=johndoe"
works the same as the request for
"s3.amazonaws.com/awsexamplebucket1/photos/2019/08/puppy.jpg", except that the
"x-user=johndoe" string is included in the Request-URI field for
the associated log record. This functionality is available in the REST interface only.
Programming considerations for extensible access log format
Occasionally we might extend the access log record format by adding new fields to the end of each line. Therefore, you should write any code that parses access logs to handle trailing fields that it might not understand.
