Implement 'all' Command for Sequential Execution of All Commands

[m18unet]

Description

Hello,

I have 3 commands named pod, service, pvc. I want to add a fourth command called all. When I execute all I want the other 3 commands to be executed in order.

Is that possible?

[DannyBen]

Yes it is possible, but probably not in the way you think.

Implementing such a solution in a generic way, would be problematic. There are arguments, and flags, and possibly other requirements for each of your commands - so what will the all command do? How will it supply these arguments? How do you ensure that the requirements for all the "child" commands are met?

So - you have several options:

Option 1: Call your other commands by re-running the CLI

Your all command can simply run your own command, as you run any other linux command. Assuming we have build and deploy command, and now a new all command:

# src/all_command.sh
./cli build --force
./cli deploy eu-west
# or $0
$0 build
$0 deploy eu-west

In real life, your script will probably be installed in the PATH (/usr/local/bin/your-script), so you should call it as you call any other linux command.

Option 2: Use functions

If you are familiar with Model-View-Controller architecture, treat the code that you write in the src/*_command.sh as if it is a controller code. It means, it should be a "dumb" short piece of code, that just calls other functions (a "model" stand in). Then, your all command can also call these functions.

For example:

The basic commands

# src/build_comnmand.sh
build_project

# src/deploy_command.sh
region=${args[region]}
deploy_project "$region"

Functions

# src/lib/build_project.sh
build_project() {
  echo "BUILDING..."
}

# src/lib/deploy_project.sh
deploy_project() {
  region="$1"
  echo "DEPLOYING TO $region..."
}

The all command

# src/all_command.sh
build_project
deploy_project "eu"
# or, if your `all` command also has arguments
deploy_project "${args[region]}"

Does this help?

[m18unet]

Excellent!

Thank you for your quick and detailed response @DannyBen.

[DannyBen]

My pleasure. Enjoy, and feel free to open an issue or a discussion if you have any problems or questions.