Awesome

lua-resty-aws

Overview

AWS SDK for OpenResty. The SDK is generated from the original AWS JavaScript repository details.

The documentation will mostly cover the specifics for this library, the actual services invoked are documented by AWS.

For a quick start on how to use this library checkout the examples of the AWS class.

Status

Not everything has been implemented, and testing is hard since it requires access to AWS resources and not just regular CI.

Example

See the example in the documentation.

Usage IMPORTANT!!

`attempt to yield across C-call boundary` error

This typically happens when initializing from within a require call. See Global settings below on how to initialize properly.

TLS and certificate failures

The http client defaults to tls name verification. For this to work, the CA store must be set. With OpenResty this is done through the lua_ssl_trusted_certificate directive. However; the compatibility module used, lua-resty-luasocket, cannot automatically read that setting, hence you have to set it manually, see the docs.

Global settings

This library depends on global settings. Especially the core services for authentication and metadata. Many of those can (also) be specified as environment variables. Environment variables can only be accessed during the OpenResty init phase. Thus, to ensure correct configuration from environment variables, the resty.aws.config module must be required on the top-level of the module using this library:

local aws_config = require("resty.aws.config")

The .global property of the aws_config variable can then be used as the global configuration. Note that when .global is first accessed, automatic region detection through the AWS metadata service is performed. Thus, it is not advisable to access it on the module level unless to avoid startup delays in non-AWS environment, caused by the requests to the metadata service timing out.

EC2 metadata

The endpoint for EC2 metadata can block (until timeout) if the SDK is used on a non-EC2 machine. In that case you might want to set the AWS_EC2_METADATA_DISABLED to a value different from false (which is the default).

        export AWS_EC2_METADATA_DISABLED=true

Installation

Installation is easiest using LuaRocks:

luarocks install lua-resty-aws

To install from the git repo:

git clone https://github.com/Kong/lua-resty-aws.git
cd lua-resty-aws
make install

Troubleshooting

MacOS has a known issue that the libexpat header file 'expat_config.h' is missing. If you run into that issue, install libexpat manually (eg. brew install expat). And then include the libexpat location when installing; luarocks install lua-resty-aws EXPAT_DIR=/path/to/expat

Details: https://github.com/lunarmodules/luaexpat/issues/32

Development

To update the SDK version being used edit the version tag in update_api_files.sh and then run:

make dev

Make sure to run make dev to pull in the generated files. Documentation can be generated using ldoc by running:

make docs

Note that distribution is a little more complex than desired. This is because the repo does not contain all the json files pulled in from the JS sdk. This in turn means that luarocks upload cannot build a rock from the repo (because it is incomplete after just being pulled).

To work around this the make pack command actually builds a .rock file that is compatible with LuaRocks. The make upload target will upload the generated rock.

See the detailed release instructions at History.

Testing

Tests are executed using Busted and LuaCheck:

busted
luacheck .

or run

make test

To do

Implement the request/response objects (more AWS like, currently Lua modules)
Implement additional signatures (only V4 currently)
Implement retries from the global config
Additional tests for other services

Copyright and license

Author: Thijs Schreijer

License: Apache 2.0

History

Versioning is strictly based on Semantic Versioning

Release process:

create a release branch VERSION=x.y.z && git checkout main && git pull && git checkout -b release/$VERSION
update the changelog below
run make clean && make dev && make test && make docs
commit as release x.y.z
push the branch, create a PR and get it merged.
tag the release commit with the version VERSION=x.y.z && git checkout main && git pull && git tag $VERSION
push the tag
run VERSION=x.y.z make pack
test the created .rock file VERSION=x.y.z && luarocks install lua-resty-aws-$VERSION-1.src.rock
upload using: VERSION=x.y.z APIKEY=abc... make upload
test installing the rock from LuaRocks

1.5.4 (23-Sep-2024)

fix: fix configure endpoint bug in getRegionPrefix 129

1.5.3 (02-Aug-2024)

fix: build the request body based on payload field 126

1.5.2 (29-Jul-2024)

fix: fix sts regional endpoint injection under several cases 123

1.5.1 (20-Jun-2024)

fix: when a "blob" type has no location specified, then use it as the body, same as with other types. 120

1.5.0 (20-May-2024)

feat: decode AWS api response json body with array metatable 114
fix: do not inject region info for sts service with VPC endpoint hostname 113

1.4.1 (19-Apr-2024)

fix: patch expanduser function to be more friendly to OpenResty environment 111

1.4.0 (20-Mar-2024)

fix: aws configuration cannot be loaded due to pl.path cannot resolve the path started with ~ 94
fix: fix the bug of missing boolean type with a value of false in the generated request body 100
security: remove the documentation entry that contains a sample access key from AWS SDK. This avoids false postive vulnerability report. 102
feat: container credential provider now supports using auth token defined in AWS_CONTAINER_AUTHORIZATION_TOKEN and AWS_CONTAINER_AUTHORIZATION_TOKEN_FILE. 107
fix: operations without inputs (eg, some S3 ones) would cause errors to be thrown 108

1.3.6 (25-Dec-2023)

fix: validator failure for some of the field types 95

1.3.5 (19-Sep-2023)

fix: lazily initialize structures to avoid c-boundary errors on require 87

1.3.4 (13-Sep-2023)

fix: remove more module-level uses of config.global 83

1.3.3 (13-Sep-2023)

fix: don't invoke region detection code on the module toplevel and advise against trying to. 81

1.3.2 (13-Sep-2023)

fix: unsigned request should support network related config option 79

1.3.1 (17-Aug-2023)

fix: fix v4 signing request should correctly canonicalized query table as well 76

1.3.0 (15-Aug-2023)

fix: fix AWS_CONTAINER_CREDENTIALS_FULL_URI parsing. #65
feat: support configure timeout on service request. #67
feat: support configure keepalive idle time on service request connection. #67
feat: support configure ssl verify on service request. #67
feat: add http/https proxy support for service request #69
fix: fix proxy-related global config var name to lowercase. #70
feat: EC2 metadata credential provider support IMDSv2 #71

1.2.3 (20-Jul-2023)

fix: fix assumeRole function name on STS. #59
fix: fix STS regional endpoint injection in build_request #62
fix: replace deprecated pl.xml with luaexpat; fix STS assume role logic. #61

1.2.2 (2-May-2023)

fix: add the SharedFileCredentials into rockspec so it can be packed and used correctly. #53
fix: the field idempotencyToken should be allowed and remain unvalidated as an opaque string. #52

1.2.1 (24-Apr-2023)

fix: fix the rds signer cannot be used in init phase. #50

1.2.0 (1-Mar-2023)

IMPORTANT-IMPORTANT-IMPORTANT feat: enable TLS name verification. This might break if your CA store is not the default system one. See usage notes. #47
fix: STS regional endpoints woudl re-inject the region on every authentication (after a token expired), causing bad hostnames to be used #45
Feat: add RDS.Signer to generate tokens for RDS DB access #44

1.1.2 (7-Dec-2022)

fix: auto detection scheme and default to tls #42

1.1.1 (21-Nov-2022)

fix: port is repeated when port is not standard #39

1.1.0 (18-Nov-2022)

fix: template handling of query string #36
fix: blob param should be in raw body #36
feat: support for credential from file #36
fix: escaping for param in uri #36
fix: handling raw body conflict with body param #36
fix: crash when no type check designated #36
fix: support for "headers" location in API template #36
fix: support new API format (bucket in host) for S3 #36

1.0.1 (20-Oct-2022)

fix: for some method incorrect URL is generates because of incorrect handling of "+" in URL template #34

1.0.0 (13-Oct-2022)

fix: latest doesn't indicate the most recent service version #28

0.5.5 (26-Sep-2022)

fix: variable names for ECS Conatiner Metatdata were missing an '_' #26

0.5.4 (19-Aug-2022)

chore: remove error message when no region is found during config initialization #24

0.5.3 (19-Aug-2022)

feat: lazy load API modules #23

0.5.2 (12-Jul-2022)

fix: relax validation to not validate some generic metadata fields. Encountered while trying to use Lambda #21
fix: better error handling when credential providers fail to load #22

0.5.1 (01-Jun-2022)

feat: socket compatibility; overriding luasocket use in phases now returns the existing setting

0.5.0 (01-Jun-2022)

feat: enable use of regional STS endpoints
deps: bumped the lua-resty-http dependency to 0.16 to disable the warnings and use the better connection building logic.
fix: added sock:settimeouts to the socket compatibility layer.
feat: implement a config object based on AWS CLI configuration.
- for most use cases it will now suffice to load the config in the init phase since it caches al predefined environment variables.
- BREAKING: getting EC2 credentials will now honor AWS_EC2_METADATA_DISABLED. Behaviour might change, but is expected to be very rare.
- BREAKING: The TokenFileWebIdentityCredentials will honor the role_session_name setting (file or env) as default name. Behaviour might change, but is expected to be very rare.

0.4.0 (06-Dec-2021)

feat: added TokenFileWebIdentityCredentials. This adds default IAM credentials to be picked up on EKS. The default AWS instance creates a CredentialProviderChain which includes TokenFileWebIdentity. So on EKS it will now pick up container based credentials instead of falling back to the underlying (more coarse) EC2 credentials.
fix: for 'query' type calls, add target action and version, which are required
fix: allow for unsigned requests for services requiring that (STS)
fix: do not validate patterns as regexes are incompatible

0.3 (02-Sep-2021)

feat: capability to fetch metadata for ECS tasks (EC2 & Fargate), versions 2, 3, and 4
feat: capability to fetch IMDS metadata (EC2 & EKS), versions 1, and 2
feat: automatic region detection, check the docs for details (utils module)
fix: EC2MetadataCredentials no longer reuses the http-client to prevent issues with the underlying compatibility layer.

0.2 (05-Aug-2021)

fix: rockspec, add Penlight dependency
fix: add proper json Content-Type header from meta-data
fix: use proper signingName for the signature