Overrides for tags and run_tags

[guikcd]

Summary

Support tags and/or run_tags in overrides.auto.pkrvars.hcl:

tags = {
  owner = "myteam"
  environment= "test"
}

run_tags = {
  owner = "packer"
  environment= "build"
}

Before this PR, users need to identity AMI and manually tags the resulted AMI.

Closes: #31

Implementation details

Define a variable for tags and run_tags for overrides

Then for each variant:

• tags are moved into locals as default_tags
• merge the default + user provided tags and define tags
• define run_tags

Testing

Building AMIs without overriding these tags are OK
Building AMIs with these tags are OK:

ALL=$(ls al*|sed "s/.pkr.hcl//")

for variant in $ALL
do
        rm -f manifest.json
        REGION=eu-west-1 make ${variant}
        ami=$(jq -r ".builds[0].artifact_id" manifest.json | awk -F':' '{print $NF}')
        # tags are set when AMI is available, not during creation
        echo "wait AMI"
        aws ec2 wait image-available --image-ids $ami
        snap=$(aws ec2 describe-images --region eu-west-1 --image-ids $ami --query "Images[0].BlockDeviceMappings[0].Ebs.SnapshotId" --output text)
        echo "check tags"
        aws ec2 describe-images --region eu-west-1 --image-ids $ami --query "Images[0].Tags[]" --output text | grep --quiet "myteam"
        if [ $? -ne 0 ]
        then
                echo "WARNING: tags are not set! for $variant / $ami"
        fi
        echo "unregister"
        aws ec2 deregister-image --image-id $ami
        echo "delete snap"
        aws ec2 delete-snapshot --snapshot-id $snap
done

New tests cover the changes: yes

Description for the changelog

Feature: Support user provided tags and run_tags.

Licensing

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