AWS CodeBuild grep and sed yaml file

codebuild_example1.txt

Example of replacing "tag" in helm values.yaml file in CodeBuild
```
      # VALUE for tag in values.yaml is tag: "121212"
      # NEW_TAG = 131313
      # YAML_FILE = values.yaml
      - "OLD_TAG=$(cat $YAML_FILE | grep -P 'tag:' | awk -F: '{ print $2 }' | sed 's/[\",]//g' | sed -e 's/^[[:space:]]*//')"
      - echo OLD_TAG=$OLD_TAG
      - sed -i "s|${OLD_TAG}|${NEW_TAG}|g" $YAML_FILE
      - cat $YAML_FILE | grep tag      
```