Exits with status code 0 when configuration JSON is malformed

[motooka]

Describe the bug
With malformed configuration JSON file, the command amazon-cloudwatch-agent-ctl exits as if it succeeds.

Steps to reproduce

• create a configuration file with broken content, which causes JSON parse error
• execute /opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-ctl -a fetch-config -m ec2 -s -c file:/opt/aws/amazon-cloudwatch-agent/bin/config.json as a root user

What did you expect to see?

• the command amazon-cloudwatch-agent-ctl exits with non-zero status code
• the command amazon-cloudwatch-agent-ctl DOES NOT say Configuration validation succeeded

What did you see instead?

• the command amazon-cloudwatch-agent-ctl exits with 0 status code
• the command amazon-cloudwatch-agent-ctl DOES say Configuration validation succeeded

What version did you use?
Version: 1.300031.0b313

What config did you use?
Config: any file with JSON parse error. For example, a file with only single character a will work for reproduction.

Environment
OS: Ubuntu 22.04 on EC2

Additional context
console log

root@ip-172-31-21-121:/opt/aws/amazon-cloudwatch-agent/bin# /opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-ctl -a fetch-config -m ec2 -s -c file:/opt/aws/amazon-cloudwatch-agent/bin/config.json
****** processing amazon-cloudwatch-agent ******
I! Trying to detect region from ec2 D! [EC2] Found active network interface I! imds retry client will retry 1 timesSuccessfully fetched the config and saved in /opt/aws/amazon-cloudwatch-agent/etc/amazon-cloudwatch-agent.d/file_config.json.tmp
Start configuration validation...
2023/11/23 11:18:27 Reading json config file path: /opt/aws/amazon-cloudwatch-agent/etc/amazon-cloudwatch-agent.d/file_config.json.tmp ...
2023/11/23 11:18:27 unable to scan config dir /opt/aws/amazon-cloudwatch-agent/etc/amazon-cloudwatch-agent.d with error: unable to parse json, error: invalid character 'a' looking for beginning of value
2023/11/23 11:18:27 No json config files found, use the default one
2023/11/23 11:18:27 I! Valid Json input schema.
2023/11/23 11:18:27 D! ec2tagger processor required because append_dimensions is set
2023/11/23 11:18:27 D! pipeline hostDeltaMetrics has no receivers
2023/11/23 11:18:27 Configuration validation first phase succeeded
I! Detecting run_as_user...
I! Trying to detect region from ec2
D! [EC2] Found active network interface
I! imds retry client will retry 1 times
/opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent -schematest -config /opt/aws/amazon-cloudwatch-agent/etc/amazon-cloudwatch-agent.toml
Configuration validation second phase succeeded
Configuration validation succeeded
amazon-cloudwatch-agent has already been stopped


root@ip-172-31-21-121:/opt/aws/amazon-cloudwatch-agent/bin# echo $?
0


root@ip-172-31-21-121:/opt/aws/amazon-cloudwatch-agent/bin# /opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-ctl -m ec2 -a status
{
  "status": "stopped",
  "starttime": "",
  "configstatus": "configured",
  "version": "1.300031.0b313"
}

[okankoAMZ]

Hello,

I was able to replicate this issue I will create a ticket in our backlog to tackle this issue.

[Xblade007]

We are also not able to get the SAP Netwear metrics using Application Insights.

2024/02/21 18:01:20 Reading json config file path: /opt/aws/amazon-cloudwatch-agent/etc/amazon-cloudwatch-agent.json ...
2024/02/21 18:01:20 Reading json config file path: /opt/aws/amazon-cloudwatch-agent/etc/amazon-cloudwatch-agent.d/ssm_AmazonCloudWatch-ApplicationInsights-SSMParameterForNWS4 ...
2024/02/21 18:01:20 Reading json config file path: /opt/aws/amazon-cloudwatch-agent/etc/amazon-cloudwatch-agent.d/ssm_AmazonCloudWatch-ApplicationInsights-SSMParameterForNWS4.tmp ...
2024/02/21 18:01:20 I! Valid Json input schema.
2024/02/21 18:01:20 D! ec2tagger processor required because append_dimensions is set
2024/02/21 18:01:20 D! metric decorator required because measurement fields are set
2024/02/21 18:01:20 D! pipeline hostDeltaMetrics has no receivers
2024/02/21 18:01:20 Configuration validation first phase succeeded

Please check this.

[oleksandrsv]

still the same and for me:
2024/08/30 11:22:42 D! ec2tagger processor required because append_dimensions is set