Packer Script exited with non-zero exit status : 127 - packer

Question

I am trying to provision an AWS AMI but the packer script terminates with the following error.
Build 'amazon-ebs' errored: Script exited with non-zero exit status: 127
==> Some builds didn't complete successfully and had errors:
--> amazon-ebs: Script exited with non-zero exit status: 127
==> Builds finished but no artifacts were created.
My template for Packer is as follows:
{
"variables": {
"aws_access_key": "{{env `MY_ACCESS_KEY`}}",
"aws_secret_key": "{{env `MY_SECRET_KEY`}}"
},
"builders": [{
"type": "amazon-ebs",
"access_key": "{{user `aws_access_key`}}",
"secret_key": "{{user `aws_secret_key`}}",
"region": "us-east-1",
"source_ami":"ami-8c1be5f6",
"instance_type": "t2.micro",
"ssh_username": "ec2-user",
"ami_name": "packer-example {{timestamp}}"
}],
"provisioners":[
{
"type": "shell",
"script": "provision.sh"
}]}
Error log is as follows: PACKER_LOG=1 packer build template.json
2017/11/01 01:30:37 [INFO] (telemetry) ending amazon-ebs
2017/11/01 01:30:37 [INFO] (telemetry) found error: Script exited with non-zero exit status: 127
2017/11/01 01:30:37 ui error: Build 'amazon-ebs' errored: Script exited with non-zero exit status: 127
2017/11/01 01:30:37 Builds completed. Waiting on interrupt barrier...
2017/11/01 01:30:37 machine readable: error-count []string{"1"}
2017/11/01 01:30:37 ui error:
==> Some builds didn't complete successfully and had errors:
2017/11/01 01:30:37 machine readable: amazon-ebs,error []string{"Script exited with non-zero exit status: 127"}
2017/11/01 01:30:37 ui error: --> amazon-ebs: Script exited with non-zero exit status: 127
2017/11/01 01:30:37 ui:
==> Builds finished but no artifacts were created.
Build 'amazon-ebs' errored: Script exited with non-zero exit status: 127
provision.sh comprises of
#!/bin/bash
sudo yum install httpd -y
sudo yum update -y
sudo aws s3 cp s3://zbcxlkxcjvlxkj/index1.html /var/www/html/ --region us-east-1
sudo service httpd start
sudo chkconfig httpd on

Answer 1

Exit code 127 is returned by bash when a command is not found. Most likely you do not have all of the commands used in your script installed on your image prior to running it.