How to write data variables to a file

[halloleo]

In my .chezmoi.toml.tmpl I set some data variables with a logic like this:

{{- if eq .chezmoi.hostname "work-name" }}
sysname = "abc"
sysgroup = "data"
sysarea = "work"
{{- else if eq .chezmoi.hostname "home-name" }}
sysname = "def"
sysgroup = ""
sysarea = "home"
{{- else if eq .chezmoi.hostname ...}}
...
{{- end }}

These variables I would like to use in my shell as well. So I thought of writing them from this template to a file .machine that my .bash_profile can source. (I don't want to make .bash_profile itself a template.) On my work computer for example this file should be written like this:

$SYSNAME = "abc"
$SYSGROUP = "data"
$SYSAREA = "work"

How can I write to a file in the .chezmoi.toml.tmpl template?

[twpayne]

How can I write to a file in the .chezmoi.toml.tmpl template?

You can't, but you can make .machine a template.

[halloleo]

Ah, I see.

Cool, it works: With .machine.tmpl I can write a file .machine which contains the particular data variables as shell variables. Excellent.

Is there a way in the template language to check whether a variable exists? (Because when I use a variable in .machine.tmpl I have not define in chezmoi.toml I get an "map has no entry for key" error.)

Or can I list all existing variables in a template?

[bradenhilton]

@halloleo Have you tried using the dig function? You could also try the Missing keys directive.

[Lockszmith-GH]

The way I solved this in my envrionment, is by having a function/or script in path named: cz-import-data
It relies on jq and sed

Assuming my chezmoi config is as follows:

> find ~/.config/chezmoi -name 'chezmoi.*' -print -exec cat '{}' \;
.../.config/chezmoi/chezmoi.toml
[data]
sysname = "abc"
sysgroup = "data"
sysarea = "work"

Defining a PREFIX (in the code below the default is CZ_DATA_ and make sure the names are uppercase via the UPPERCASE env variable.
The output will look like:

$ import-cz-data
CZ_DATA_SYSAREA="work"
CZ_DATA_SYSGROUP="data"
CZ_DATA_SYSNAME="abc"

The idea is that running the following commands allows you to evaluate/source those into environment variables:

. <( import-cz-data )

❯ echo $CZ_DATA_SYSAREA
work

This is the code of cz-import-data

cz-import-data() {
    # Use this with eval: eval $(cz-import-data)
    local UPPERCASE='|ascii_upcase'
    local PREFIX="CZ_DATA_"
    [[ "$1" == "promptString" ]] && unset UPPERCASE PREFIX
    local RESULTS=$(
        chezmoi data --format json \
            | jq -r ".chezmoi.config.data" \
            | jq -r "
                to_entries[] |
                    \"$PREFIX\(.key${UPPERCASE})=\\\"\(.value)\\\"\"
            "
        )
    if [[ "$1" == "promptString" ]] ; then
        printf "$RESULTS" | tr '\n' ',' | sed 's/"//g; s/^\(.*\),$/"\1/g;'
    else
        echo "$RESULTS"
    fi  
}

[Lockszmith-GH]

Oh, I completely forgot, the 'promptString' stuff.

With a .chezmoi.toml.tmpl like this:

{{- $sysname  := promptStringOnce . "sysname"  "System name"  -}}
{{- $sysgroup := promptStringOnce . "sysgroup" "System group" -}}
{{- $sysarea  := promptStringOnce . "sysarea"  "System area"  -}}

[data]
{{- if ($sysname) }}
    sysname = {{ $sysname | quote }}
{{- end -}}
{{- if ($sysgroup) }}
    sysgroup = {{ $sysgroup | quote }}
{{- end -}}
{{- if ($sysarea) }}
    sysarea = {{ $sysarea | quote }}
{{- end }}

When initializing it prompts for the values, and to re-initialize you can run the following command:

$ chezmoi init --promptString $(cz-import-data promptString) [--prompt]
System name? one
System group? two
System area? three

$ cz-import-data
CZ_DATA_SYSAREA="three"
CZ_DATA_SYSGROUP="two"
CZ_DATA_SYSNAME="one"

The optional --prompt will force prompting for all. Without it, it will only prompt for missing data.

Hope this becomes useful to someone.

[halloleo]

Thanks for this. Very sophisticated. I keep it in mind as an option