Scenario

Each application environment (staging, dev, prod) has its own configuration file stored under /etc/app/envs/, and each file currently has multi_az = false and availability_zone = "us-east-1a". Manually editing each file is error-prone and inefficient, so the change must be automated.

Task

Locate all .conf files under /etc/app/envs/ across different environment subdirectories, update the multi_az setting from false to true, modify the availability_zone line to include two zones "us-east-1a,us-east-1b", perform these edits in-place while preserving all other configuration values.

Example

# Before (single-AZ configuration)

region = "us-east-1"
availability_zone = "us-east-1a"
multi_az = false

# After (multi-AZ configuration enabled)

region = "us-east-1"
availability_zone = "us-east-1a,us-east-1b"
multi_az = true

Step 1: Locate all .conf files under /etc/app/envs/

find /etc/app/envs/ -type f -name "*.conf"

Look at the output to identify which files will be modified.

Step 2: View one of the files to see its current content

cat /etc/app/envs/dev/config.conf

Look for the lines with availability_zone = "us-east-1a" and multi_az = false.

Step 3: Update the availability_zone setting in all .conf files

find /etc/app/envs/ -type f -name "*.conf" -exec sed -i 's/availability_zone = "us-east-1a"/availability_zone = "us-east-1a,us-east-1b"/' {} \;

Step 4: Update the multi_az setting in all .conf files

find /etc/app/envs/ -type f -name "*.conf" -exec sed -i 's/multi_az = false/multi_az = true/' {} \;

Step 5: Verify the changes in all files

cat /etc/app/envs/dev/config.conf
cat /etc/app/envs/staging/config.conf
cat /etc/app/envs/prod/config.conf

Check that you see availability_zone = "us-east-1a,us-east-1b" and multi_az = true. Confirm that all files show the updated values.