nix-templating/lib.nix
2025-08-21 09:39:13 +02:00

82 lines
2.7 KiB
Nix

{
pkgs,
lib ? pkgs.lib,
nix_templater ? pkgs.callPackage ./pkgs/nix_templater { },
}:
let
escapeJson = {
"\"" = ''\"'';
"\\" = ''\\'';
};
in
rec {
# placeholder to be substituted with the content of a secret file
fileContents = file: {
outPath = "<${builtins.placeholder "nix_template"}${toString file}${builtins.placeholder "nix_template"}>";
file = file;
};
# make a template with placeholders from a text
templateText = {
name,
text,
outPath,
owner ? "root",
group ? "",
mode ? "0400",
translations ? {},
}:
pkgs.runCommand name {
textBeforeTemplate = text;
script = ''
#!/bin/sh
${nix_templater}/bin/nix_templater ${builtins.placeholder "out"}/template ${builtins.placeholder "nix_template"} "${outPath}" '${lib.strings.toJSON translations}'
'';
passAsFile = [ "script" "textBeforeTemplate" ];
} ''
mkdir -p $out/bin
cp $textBeforeTemplatePath $out/template
cp $scriptPath $out/bin/${name}
chmod +x $out/bin/${name}
chown ${owner}:${group} $out/bin/${name}
chmod ${mode} $out/bin/${name}
'';
# make a template with placeholders from a file
templateFromFile = { name, templateFile, outPath, translations ? {} }:
pkgs.runCommand name {
inherit templateFile;
script = ''
#!/bin/sh
${nix_templater}/bin/nix_templater ${builtins.placeholder "out"}/template ${builtins.placeholder "nix_template"} "${outPath}" '${lib.strings.toJSON translations}'
'';
passAsFile = [ "script" ];
} ''
mkdir -p $out/bin
cp $templateFile $out/template
cp $scriptPath $out/bin/${name}
chmod +x $out/bin/${name}
'';
translateFile = translations: generator: { name, value, outPath }: templateFromFile {
inherit name outPath translations;
templateFile = generator value;
};
translateText = translations: generator: { name, value, outPath }: templateText {
inherit name outPath translations;
text = generator value;
};
# escaping: https://www.json.org/json-en.html
templateJson = translateFile escapeJson (pkgs.writers.writeJSON "template.json");
# just json
templateYaml = translateFile escapeJson (pkgs.writers.writeYAML "template.yaml");
# escaping: technically also control characters (U+0000 to U+001F): https://toml.io/en/v0.3.0#string
templateToml = translateFile escapeJson (pkgs.writers.writeTOML "template.toml");
# escaping: https://git.kernel.org/pub/scm/git/git.git/tree/Documentation/config.txt?id=a54a84b333adbecf7bc4483c0e36ed5878cac17b#n47
templateIniWith = options: translateText escapeJson (lib.generators.toINI options);
templateIni = templateIniWith { };
}