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simple and robust nix package wrapper function
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5.6 kB · 183 lines · Created 1y ago Nix
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184/** Wraps a package with flags and env vars.
The wrapper derivation has each specified binary in the original package replaced by a wrapper with the specified flags and environment variables. Every other file from the original derivation is symlinked to by the new derivation, except any file referencing the original $pkg will be cloned and have that reference replaced by the wrapper derivation's $out.
# Example
```nix mkWrapper = import ./wrap.nix; editor = mkWrapper pkgs { pkg = pkgs.helix; hx = { env.idk = "hi"; prependFlags = [ "--config" "./helix.toml" ]; }; }; ```
# Type
``` mkWrapper :: Pkgs -> { pkg : Derivation, pname? : String, additionalDependencies? : [Derivation], <bin> : { env? : AttrSet String, prependFlags? : [String] appendFlags? : [String] } } -> Derivation ```
# Arguments
pkgs : An instance of nixpkgs
pkg : The derivation to wrap
pname : An optional name for the wrapped package, defaults to `pkg.name`
additionalDependencies : An optional list of additional derivations to include in the wrapped environment
<bin> : Variadic number of attrsets in the form bin = { env?, flags? }, where `bin` is the name of the binary that `pkg` outputs that you want to wrap. `env` and `flags` are detailed below.
env : An optional attrset specifying environment variables to set inside the wrapped environment, defaults to `{}`
prependFlags : An optional list specifying flags to append to the wrapped binary, defaults to `[]`. These flags go before your arguments, in the form `bin --prepended $@`.
appendFlags : An optional list specifying flags to append to the wrapped binary, defaults to `[]` These flags go after your arguments, in the form `bin $@ --appended`.*/pkgs:let wrap = { pkg, pname ? pkg.pname, version ? pkg.version, additionalDependencies ? [ ], ... }@args:
let lib = pkgs.lib; in
assert lib.isDerivation pkg || throw "'pkg' must be a derivation (e.g. pkgs.hello)"; assert lib.isString pname || throw "'name' must be a string";
let # all keyword kwargs are bins binaries = builtins.removeAttrs args [ "pkg" "pname" "version" "additionalDependencies" ];
wrapCommands = lib.mapAttrsToList ( bin: { prependFlags ? [ ], appendFlags ? [ ], env ? { }, }: assert (lib.isList prependFlags && lib.all lib.isString prependFlags) || throw "'${bin}.addFlags' must be a list of strings"; assert (lib.isList appendFlags && lib.all lib.isString appendFlags) || throw "'${bin}.addFlags' must be a list of strings"; assert (lib.isAttrs env && lib.all lib.isString (lib.attrValues env)) || throw "'${bin}.env' must be an attribute set of strings"; let envArgs = lib.concatStringsSep " " (lib.mapAttrsToList (k: v: "--set '${k}' '${v}'") env); in '' wrapProgram $out/bin/${bin} \ --add-flags "${builtins.toString prependFlags}" \ --append-flags "${builtins.toString appendFlags}" \ ${envArgs} '' ) binaries;
# nasty script to replace all text references to ${pkg} with ${out} # this is necessary because some files that get symlinked into the new # package directory ($out) will still reference ${pkg}, leading to # unexpected behavior fixReferences = '' # iterate through every file/symlink in $out find "$out" \( -type l -o -type f \) | while read -r item; do # if item is a symlink, we want to (recursively) find the file it # points to, read it, and if it contains $pkg, overwrite the symlink # with a regular file to replace $pkg with $out if [ -L "$item" ]; then # redirection is to ignore broken symlinks target=$(readlink -f "$item" 2>/dev/null || true)
# if our target is a nonempty file containing pkg, replace item with target if [ -n "$target" ] && [ -f "$target" ] && grep -F -q "${pkg}" "$target"; then rm "$item" cp "$target" "$item" # otherwise, skip the file replacement code else continue fi fi
# $item is guaranteed to be a regular file if grep -F -q "${pkg}" "$item"; then # ensure $item is writeable [ -w "$item" ] || chmod +w "$item" # replace all occurances of $pkg with $out sed -i "s|${pkg}|$out|g" "$item" || true fi done ''; in pkgs.symlinkJoin { inherit pname; inherit version; passthru = (pkg.passthru or { }) // { unwrapped = pkg;
override = overrideArgs: let newPkg = pkg.override overrideArgs; newArgs = args // { pkg = newPkg; }; in wrap newArgs;
overrideAttrs = f: let newPkg = pkg.overrideAttrs f; newArgs = args // { pkg = newPkg; }; in wrap newArgs; }; paths = [ pkg ]; buildInputs = [ pkgs.makeWrapper ] ++ additionalDependencies; postBuild = lib.concatStringsSep "\n" (wrapCommands ++ [ fixReferences ]); };inwrap