How can I execute a template-based script before running chezmoi apply?

[jbwfu]

My .chezmoiexternal.yaml.tmpl file uses a YAML file located at .chezmoi.cacheDir, which is generated by a script that records the installation status of programs. However, the script itself is dynamically generated based on a template. What would be the best way to handle this?

Currently, my approach is as follows:

my .chezmoi.yaml.tmpl:

{{/* Write a script to check the installation status of programs. */}}
{{- $filepath := joinPath .chezmoi.cacheDir "checkinstalled.sh" -}}
{{- output "sh" "-c" (list "mkdir" "-p" .chezmoi.cacheDir | join " ") -}}
{{- $context := output "sh" "-c" (list "chezmoi" "execute-template" "'{{" "includeTemplate" "\"scripts/checkinstalled.sh.tmpl\"" "." "}}'" ">" $filepath | join " ") -}}

hooks:
  apply:
    pre:
      command: "sh"
      args: [{{- $filepath | quote -}}]

my .chezmoitemplates/scripts/checkinstalled.sh.tmpl:

#!/usr/bin/env sh

programs= {{- .programs.needcheck | join " " | quote }}

mkdir -p {{ .chezmoi.cacheDir | quote }}

for program in $programs; do
  installed=true
  command -v "$program" > /dev/null 2>&1 || installed=false

  printf "%s:\n  installed: %s\n" "$program" "$installed"
done > {{ joinPath .chezmoi.cacheDir "installstatus.yaml" }}

[bradenhilton]

Have you tried a run_before_ script?

[jbwfu]

According to the content in the Application order, run_before_ is supposed to be executed after reading .chezmoiexternal.yaml.tmpl.

My actual testing also confirms this: without adding any hooks, an error occurs and the process exits because the corresponding YAML file cannot be found before the run_before_ script is executed.

[bradenhilton]

What are you trying to achieve with this? It's not immediately clear based on your post and it's possible there is a better way to do it.

What are the contents of your .chezmoiexternal.yaml.tmpl?

[jbwfu]

.chezmoiexternal.yaml.tmpl:

{{- $data := fromYaml (include (joinPath .chezmoi.cacheDir "programs.yaml")) -}}
{{- if ne .chezmoi.os "windows" -}}

{{- if $data.programs.zsh.installed -}}
.config/shell/oh-my-zsh:
  type: git-repo
  url: https://github.com/ohmyzsh/ohmyzsh.git
  refreshPeriod: 168h
{{- end }}

{{- if $data.programs.tmux.installed }}
.config/tmux/oh-my-tmux:
  type: git-repo
  url: https://github.com/gpakosz/.tmux.git
  refreshPeriod: 168h
{{- end -}}

{{- end -}}

I use the generated programs.yaml file to track the installation status of programs and decide whether to fetch the corresponding remote content based on that installation status. My current configuration achieves this goal, but it is somewhat complicated, and I would like a simpler way to do it.

[bradenhilton]

Could you not replace your script with lookPaths in your external template? e.g.

{{- if lookPath "zsh" -}}
.config/shell/oh-my-zsh:
  type: git-repo
  url: https://github.com/ohmyzsh/ohmyzsh.git
  refreshPeriod: 168h
{{- end }}

For what it's worth, I prefer to build my configs with dicts/lists etc., then finally output them with to{Yaml,Toml,PrettyJson}. For example, here are my externals for mpv:

{{- $externals := dict -}}

{{- with $repo := "CogentRedTester/mpv-sub-select" -}}
{{-   $_ := set $externals "scripts/sub-select.lua" (dict
        "type" "file"
        "url" (printf "https://github.com/%s/raw/master/sub-select.lua" $repo)
        "refreshPeriod" "168h")
-}}
{{- end -}}

{{- with $owner := "po5" -}}
{{-   range $repo := (list "chapterskip" "thumbfast") -}}
{{-     $_ := set $externals (printf "scripts/%s.lua" $repo ) (dict
          "type" "file"
          "url" (printf "https://github.com/%[1]s/%[2]s/raw/master/%[2]s.lua" $owner $repo)
          "refreshPeriod" "168h")
-}}
{{-   end -}}
{{- end -}}

{{- with $repo := "tomasklaen/uosc" -}}
{{-   with $version := (gitHubLatestRelease $repo).GetTagName -}}
{{-     $_ := set $externals "fonts" (dict
          "type" "archive"
          "url" (printf "https://github.com/%s/releases/download/%s/uosc.zip" $repo $version)
          "stripComponents" 1
          "include" (list "fonts/**"))
-}}
{{-     $_ := set $externals "scripts" (dict
          "type" "archive"
          "url" (printf "https://github.com/%s/releases/download/%s/uosc.zip" $repo $version)
          "stripComponents" 1
          "include" (list "scripts/**")
          "exclude" (list 
            "fonts/**"
            "scripts/uosc/char-conv/**"))
-}}
{{-   end -}}
{{- end -}}

{{- $externals | toToml -}}

And here is the result of the template:

[fonts]
include = ['fonts/**']
stripComponents = 1
type = 'archive'
url = 'https://github.com/tomasklaen/uosc/releases/download/5.7.0/uosc.zip'

[scripts]
exclude = ['fonts/**', 'scripts/uosc/char-conv/**']
include = ['scripts/**']
stripComponents = 1
type = 'archive'
url = 'https://github.com/tomasklaen/uosc/releases/download/5.7.0/uosc.zip'

['scripts/chapterskip.lua']
refreshPeriod = '168h'
type = 'file'
url = 'https://github.com/po5/chapterskip/raw/master/chapterskip.lua'

['scripts/sub-select.lua']
refreshPeriod = '168h'
type = 'file'
url = 'https://github.com/CogentRedTester/mpv-sub-select/raw/master/sub-select.lua'

['scripts/thumbfast.lua']
refreshPeriod = '168h'
type = 'file'
url = 'https://github.com/po5/thumbfast/raw/master/thumbfast.lua'

[jbwfu]

I'm quite new to using chezmoi, and I'm not yet familiar with some of the more efficient approaches. The method you provided is exactly the effect I was looking for, and the built-in function is indeed more suitable. Thank you!

[halostatue]

You can also see a really good example in my programs.tmpl.