DRYer VARs definition

[maclarensg]

For variables, i categorised them as 2 category:

1. VARS that are set during before the runtime of a task. E.g. Env vars, env vars file and etc
2. And VARS that are unknown until execution and runtime of task.

Since I can't define 2. in 1. then if I have several task asking for the same parameters. Wouldn't it be nice to be defined in some place and then reference by the tasks later.

example.

version: '3'
dotenv: ['setup.config']

tasks:
  shell:
    vars:
      ACCOUNT: '{{default "" .ACCOUNT}}'
      REGION: '{{default "ap-southeast-1" .REGION}}'
      GROUP: '{{default "" .GROUP}}'
      PATH: '$(case ${TIER} in 1) echo "{{.ACCOUNT}}" ;; 2) echo "{{.ACCOUNT}}/{{.REGION}}" ;; 3) echo "{{.ACCOUNT}}/{{.REGION}}/{{.GROUP}}" ;; *) echo "Unsupported tier" && exit 1 ;; esac)'
      COMMAND: '{{.CMD}} run --platform {{.PLATFORM}} --rm -it -e AWS_PROFILE=devops -v {{.HOME}}/.aws:/root/.aws -v {{.PWD}}/.gitconfig:/root/.gitconfig -v {{.PWD}}:/tf -v {{.PWD}}/local_modules:/tf/workspaces/{{.PATH}}/local_modules -w /tf/workspaces/{{.PATH}} --entrypoint \"\" {{.IMAGE}}'
    cmds:
      - |
        [ "{{.ACCOUNT}}" ] || ( echo "ACCOUNT is required."; exit 1 )
        [ "{{.TIER}}" -ge 2 ] && [ -z "{{.REGION}}" ] && echo "REGION is required." && exit 1 || true
        [ "{{.TIER}}" -eq 3 ] && [ -z "{{.GROUP}}" ] && echo "GROUP is required." && exit 1 || true
      - echo "{{.ACCOUNT}}"
      - echo "{{.REGION}}"
      - echo "{{.PATH}}"
      - eval "{{.COMMAND}}" /bin/sh

  scaffold:
    vars:
      ACCOUNT: '{{default "" .ACCOUNT}}'
      ACCOUNT_ID: '{{default "" .ACCOUNT_ID}}'
      REGION: '{{default "ap-southeast-1" .REGION}}'
      GROUP: '{{default "" .GROUP}}'
      PATH: '$(case ${TIER} in 1) echo "{{.ACCOUNT}}" ;; 2) echo "{{.ACCOUNT}}/{{.REGION}}" ;; 3) echo "{{.ACCOUNT}}/{{.REGION}}/{{.GROUP}}" ;; *) echo "Unsupported tier" && exit 1 ;; esac)'
    cmds:
      - |
        [ "{{.ACCOUNT}}" ]    || ( echo "ACCOUNT is required."; exit 1 )
        [ "{{.ACCOUNT_ID}}" ] || ( echo "ACCOUNT_ID is required."; exit 1 )
        [ "{{.TIER}}" -ge 2 ] && [ -z "{{.REGION}}" ] && echo "REGION is required." && exit 1 || true
        [ "{{.TIER}}" -eq 3 ] && [ -z "{{.GROUP}}" ] && echo "GROUP is required." && exit 1 || true

      - | 
        [ -d "workspaces/{{.PATH}}" ]                || mkdir -p workspaces/{{.PATH}}
        [ -d "workspaces/{{.PATH}}/local_modules" ]  || ( cd workspaces/{{.PATH}}; ln -s {{.BACK}}/local_modules . )
        [ -f "workspaces/{{.PATH}}/auto.tf" ]   	   || ( cd workspaces/{{.PATH}}; ln -s {{.BACK}}/base/auto.tf . )
        [ -f "workspaces/{{.PATH}}/main.tf" ]   	   || ( touch ./workspaces/{{.PATH}}/main.tf )
        [ -f "workspaces/{{.PATH}}/vars.tf" ]   	   || ( cp ./base/vars.tf ./workspaces/{{.PATH}}/ ) 
        [ -d "workspaces/{{.PATH}}/resources" ] 	   || ( mkdir -p workspaces/{{.PATH}}/resources; echo "{}" > workspaces/{{.PATH}}/resources/main.yaml; ) 
      - |
        echo "ACCOUNT: {{.ACCOUNT}}" > tmp/.config
        echo "ACCOUNT_ID: {{.ACCOUNT_ID}}" >> tmp/.config
        [ "{{.TIER}}" -ge 2 ] && echo "REGION: {{.REGION}}" >> tmp/.config
        [ "{{.TIER}}" -eq 3 ] && echo "GROUP: {{.GROUP}}" >> tmp/.config
        echo "PROJECT: {{.PROJECT}}" >> tmp/.config
        echo "DOMAIN: {{.DOMAIN}}" >> tmp/.config      

On the above example, variables that at in the cat1 section are store in setup.config which is a env file actually
You can see both shell and scaffold requires ACCOUNT(Mandatory), REGION and GROUP (optional) ....
And PATH is set during the runtime.

Now if there is a means to define it some place like

vars_template:
   template1:
      ACCOUNT: '{{default "" .ACCOUNT}}'
      REGION: '{{default "ap-southeast-1" .REGION}}'
      GROUP: '{{default "" .GROUP}}' 
      PATH: '$(case ${TIER} in 1) echo "{{.ACCOUNT}}" ;; 2) echo "{{.ACCOUNT}}/{{.REGION}}" ;; 3) echo "{{.ACCOUNT}}/{{.REGION}}/{{.GROUP}}" ;; *) echo "Unsupported tier" && exit 1 ;; esac)'

then later

tasks:
  shell:
    use_var_template:
      - template1
    vars:
      COMMAND: '{{.CMD}} run --platform {{.PLATFORM}} --rm -it -e AWS_PROFILE=devops -v {{.HOME}}/.aws:/root/.aws -v {{.PWD}}/.gitconfig:/root/.gitconfig -v {{.PWD}}:/tf -v {{.PWD}}/local_modules:/tf/workspaces/{{.PATH}}/local_modules -w /tf/workspaces/{{.PATH}} --entrypoint \"\" {{.IMAGE}}'