Read git hash from RELEASE_COMMIT file if possible

[danehlim]

Summary

Read git hash from RELEASE_COMMIT file if possible

Implementation details

• Prior to executing gitHash() function in version-gen.go, try to read hash from RELEASE_COMMIT file instead using new releaseCommitGitHash() function
• Log relevant information in gitHash() and releaseCommitGitHash() functions in version-gen.go
• Add RELEASE_COMMIT file to amazon-linux-sources.tgz in Makefile
• Use os.ReadFile instead of ioutil.ReadFile in version-gen.go since ioutil package is deprecated as of Go 1.16

Testing

In the repo root, create a test RELEASE_COMMIT file, run version-gen.go, and verify that the correct hash is obtained.

$ echo "1a2b3c4d5e6f78901a2b3c4d5e6f78901a2b" > RELEASE_COMMIT
$ cd agent/version 
$ GO111MODULE=off go run gen/version-gen.go
2022/12/07 10:31:04 Successfully retrieved full hash value from RELEASE_COMMIT file, fullHashStr: 1a2b3c4d5e6f78901a2b3c4d5e6f78901a2b
$ cat version.go
// This is an autogenerated file and should not be edited.

// Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License"). You may
// not use this file except in compliance with the License. A copy of the
// License is located at
//
//      http://aws.amazon.com/apache2.0/
//
// or in the "license" file accompanying this file. This file is distributed
// on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
// express or implied. See the License for the specific language governing
// permissions and limitations under the License.

// Package version contains constants to indicate the current version of the
// agent. It is autogenerated
package version

// Please DO NOT commit any changes to this file (specifically the hash) except
// for those created by running ./scripts/update-version at the root of the
// repository. Only the 'Version' const should change in checked-in source code

// Version is the version of the Agent
const Version = "1.67.0"

// GitDirty indicates the cleanliness of the git repo when this agent was built
const GitDirty = true

// GitShortHash is the short hash of this agent build
const GitShortHash = "1a2b3c4d"

New tests cover the changes: no

Description for the changelog

Read git hash from RELEASE_COMMIT file if possible

Licensing

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[sparrc]

When and how is the RELEASE_COMMIT file generated?

[YashdalfTheGray]

Looks good!