Skip to content

Commit

Permalink
buildGoPackage: remove (#349478)
Browse files Browse the repository at this point in the history
  • Loading branch information
@Aleksanaa
Aleksanaa authored Nov 19, 2024
2 parents 09a0f56 + 41d7136 commit 0ecc88f
Show file tree
Hide file tree
Showing 7 changed files with 117 additions and 479 deletions.
256 changes: 97 additions & 159 deletions doc/languages-frameworks/go.section.md
View file
Original file line number Diff line number Diff line change
Expand Up @@ -7,32 +7,6 @@ The function `buildGoModule` builds Go programs managed with Go modules. It buil
- An intermediate fetcher derivation called `goModules`. This derivation will be used to fetch all the dependencies of the Go module.
- A final derivation will use the output of the intermediate derivation to build the binaries and produce the final output.

### Attributes of `buildGoModule` {#buildgomodule-parameters}

The `buildGoModule` function accepts the following parameters in addition to the [attributes accepted by both Go builders](#ssec-go-common-attributes):

- `vendorHash`: is the hash of the output of the intermediate fetcher derivation (the dependencies of the Go modules).

`vendorHash` can be set to `null`.
In that case, rather than fetching the dependencies, the dependencies already vendored in the `vendor` directory of the source repo will be used.

To avoid updating this field when dependencies change, run `go mod vendor` in your source repo and set `vendorHash = null;`.
You can read more about [vendoring in the Go documentation](https://go.dev/ref/mod#vendoring).

To obtain the actual hash, set `vendorHash = lib.fakeHash;` and run the build ([more details here](#sec-source-hashes)).
- `proxyVendor`: If `true`, the intermediate fetcher downloads dependencies from the
[Go module proxy](https://go.dev/ref/mod#module-proxy) (using `go mod download`) instead of vendoring them. The resulting
[module cache](https://go.dev/ref/mod#module-cache) is then passed to the final derivation.

This is useful if your code depends on C code and `go mod tidy` does not include the needed sources to build or
if any dependency has case-insensitive conflicts which will produce platform-dependent `vendorHash` checksums.

Defaults to `false`.
- `modPostBuild`: Shell commands to run after the build of the goModules executes `go mod vendor`, and before calculating fixed output derivation's `vendorHash`.
Note that if you change this attribute, you need to update `vendorHash` attribute.
- `modRoot`: The root directory of the Go module that contains the `go.mod` file.
Defaults to `./`, which is the root of `src`.

### Example for `buildGoModule` {#ex-buildGoModule}

The following is an example expression using `buildGoModule`:
Expand Down Expand Up @@ -62,17 +36,45 @@ The following is an example expression using `buildGoModule`:
}
```

### Obtaining and overriding `vendorHash` for `buildGoModule` {#buildGoModule-vendorHash}
## Attributes of `buildGoModule` {#buildgomodule-parameters}

Many attributes [controlling the build phase](#variables-controlling-the-build-phase) are respected by `buildGoModule`. Note that `buildGoModule` reads the following attributes also when building the `vendor/` goModules fixed output derivation as well:

- [`sourceRoot`](#var-stdenv-sourceRoot)
- [`prePatch`](#var-stdenv-prePatch)
- [`patches`](#var-stdenv-patches)
- [`patchFlags`](#var-stdenv-patchFlags)
- [`postPatch`](#var-stdenv-postPatch)
- [`preBuild`](#var-stdenv-preBuild)
- `env`: useful for passing down variables such as `GOWORK`.

To control test execution of the build derivation, the following attributes are of interest:

- [`checkInputs`](#var-stdenv-checkInputs)
- [`preCheck`](#var-stdenv-preCheck)
- [`checkFlags`](#var-stdenv-checkFlags)

In addition to the above attributes, and the many more variables respected also by `stdenv.mkDerivation`, `buildGoModule` respects Go-specific attributes that tweak them to behave slightly differently:

### `vendorHash` {#var-go-vendorHash}

Hash of the output of the intermediate fetcher derivation (the dependencies of the Go modules).

`vendorHash` can be set to `null`.
In that case, rather than fetching the dependencies, the dependencies already vendored in the `vendor` directory of the source repo will be used.

To avoid updating this field when dependencies change, run `go mod vendor` in your source repo and set `vendorHash = null;`.
You can read more about [vendoring in the Go documentation](https://go.dev/ref/mod#vendoring).

To obtain the hash, set `vendorHash = lib.fakeHash;` and run the build. ([more details here](#sec-source-hashes)).
Another way is to use use `nix-prefetch` to obtain the hash. The following command gets the value of `vendorHash` for package `pet`:

We can use `nix-prefetch` to obtain the actual hash. The following command gets the value of `vendorHash` for package `pet`:

```sh
cd path/to/nixpkgs
nix-prefetch -E "{ sha256 }: ((import ./. { }).my-package.overrideAttrs { vendorHash = sha256; }).goModules"
```

To obtain the hash without external tools, set `vendorHash = lib.fakeHash;` and run the build. ([more details here](#sec-source-hashes)).

`vendorHash` can be overridden with `overrideAttrs`. Override the above example like this:

```nix
Expand All @@ -91,144 +93,29 @@ To obtain the hash without external tools, set `vendorHash = lib.fakeHash;` and
}
```

### Overriding `goModules` {#buildGoModule-goModules-override}

Overriding `<pkg>.goModules` by calling `goModules.overrideAttrs` is unsupported. Still, it is possible to override the `vendorHash` (`goModules`'s `outputHash`) and the `pre`/`post` hooks for both the build and patch phases of the primary and `goModules` derivation. Alternatively, the primary derivation provides an overridable `passthru.overrideModAttrs` function to store the attribute overlay implicitly taken by `goModules.overrideAttrs`. Here's an example usage of `overrideModAttrs`:

```nix
{
pet-overridden = pet.overrideAttrs (
finalAttrs: previousAttrs: {
passthru = previousAttrs.passthru // {
# If the original package has an `overrideModAttrs` attribute set, you'd
# want to extend it, and not replace it. Hence we use
# `lib.composeExtensions`. If you are sure the `overrideModAttrs` of the
# original package trivially does nothing, you can safely replace it
# with your own by not using `lib.composeExtensions`.
overrideModAttrs = lib.composeExtensions previousAttrs.passthru.overrideModAttrs (
finalModAttrs: previousModAttrs: {
# goModules-specific overriding goes here
postBuild = ''
# Here you have access to the `vendor` directory.
substituteInPlace vendor/github.com/example/repo/file.go \
--replace-fail "panic(err)" ""
'';
}
);
};
}
);
}
```

## `buildGoPackage` (legacy) {#ssec-go-legacy}

The function `buildGoPackage` builds legacy Go programs, not supporting Go modules.

::: {.warning}
`buildGoPackage` is deprecated and will be removed for the 25.05 release.
:::

### Migrating from `buildGoPackage` to `buildGoModule` {#buildGoPackage-migration}

Go modules, released 6y ago, are now widely adopted in the ecosystem.
Most upstream projects are using Go modules, and the tooling previously used for dependency management in Go is mostly deprecated, archived or at least unmaintained at this point.

In case a project doesn't have external dependencies or dependencies are vendored in a way understood by `go mod init`, migration can be done with a few changes in the package.

- Switch the builder from `buildGoPackage` to `buildGoModule`
- Remove `goPackagePath` and other attributes specific to `buildGoPackage`
- Set `vendorHash = null;`
- Run `go mod init <module name>` in `postPatch`

In case the package has external dependencies that aren't vendored or the build setup is more complex the upstream source might need to be patched.
Examples for the migration can be found in the [issue tracking migration withing nixpkgs](https://github.com/NixOS/nixpkgs/issues/318069).

### Example for `buildGoPackage` {#example-for-buildgopackage}

In the following is an example expression using `buildGoPackage`, the following arguments are of special significance to the function:

- `goPackagePath` specifies the package's canonical Go import path.
- `goDeps` is where the Go dependencies of a Go program are listed as a list of package source identified by Go import path. It could be imported as a separate `deps.nix` file for readability. The dependency data structure is described below.

```nix
{
deis = buildGoPackage rec {
pname = "deis";
version = "1.13.0";
goPackagePath = "github.com/deis/deis";
src = fetchFromGitHub {
owner = "deis";
repo = "deis";
rev = "v${version}";
hash = "sha256-XCPD4LNWtAd8uz7zyCLRfT8rzxycIUmTACjU03GnaeM=";
};
goDeps = ./deps.nix;
};
}
```

The `goDeps` attribute can be imported from a separate `nix` file that defines which Go libraries are needed and should be included in `GOPATH` for `buildPhase`:
### `proxyVendor` {#var-go-proxyVendor}

```nix
# deps.nix
[ # goDeps is a list of Go dependencies.
{
# goPackagePath specifies Go package import path.
goPackagePath = "gopkg.in/yaml.v2";
fetch = {
# `fetch type` that needs to be used to get package source.
# If `git` is used there should be `url`, `rev` and `hash` defined next to it.
type = "git";
url = "https://gopkg.in/yaml.v2";
rev = "a83829b6f1293c91addabc89d0571c246397bbf4";
hash = "sha256-EMrdy0M0tNuOcITaTAmT5/dPSKPXwHDKCXFpkGbVjdQ=";
};
}
{
goPackagePath = "github.com/docopt/docopt-go";
fetch = {
type = "git";
url = "https://github.com/docopt/docopt-go";
rev = "784ddc588536785e7299f7272f39101f7faccc3f";
hash = "sha256-Uo89zjE+v3R7zzOq/gbQOHj3SMYt2W1nDHS7RCUin3M=";
};
}
]
```
If `true`, the intermediate fetcher downloads dependencies from the
[Go module proxy](https://go.dev/ref/mod#module-proxy) (using `go mod download`) instead of vendoring them. The resulting
[module cache](https://go.dev/ref/mod#module-cache) is then passed to the final derivation.

To extract dependency information from a Go package in automated way use [go2nix (deprecated)](https://github.com/kamilchm/go2nix). It can produce complete derivation and `goDeps` file for Go programs.
This is useful if your code depends on C code and `go mod tidy` does not include the needed sources to build or
if any dependency has case-insensitive conflicts which will produce platform-dependent `vendorHash` checksums.

You may use Go packages installed into the active Nix profiles by adding the following to your ~/.bashrc:
Defaults to `false`.

```bash
for p in $NIX_PROFILES; do
GOPATH="$p/share/go:$GOPATH"
done
```

## Attributes used by both builders {#ssec-go-common-attributes}
### `modPostBuild` {#var-go-modPostBuild}

Many attributes [controlling the build phase](#variables-controlling-the-build-phase) are respected by both `buildGoModule` and `buildGoPackage`. Note that `buildGoModule` reads the following attributes also when building the `vendor/` goModules fixed output derivation as well:
Shell commands to run after the build of the goModules executes `go mod vendor`, and before calculating fixed output derivation's `vendorHash`.
Note that if you change this attribute, you need to update `vendorHash` attribute.

- [`sourceRoot`](#var-stdenv-sourceRoot)
- [`prePatch`](#var-stdenv-prePatch)
- [`patches`](#var-stdenv-patches)
- [`patchFlags`](#var-stdenv-patchFlags)
- [`postPatch`](#var-stdenv-postPatch)
- [`preBuild`](#var-stdenv-preBuild)
- `env`: useful for passing down variables such as `GOWORK`.

To control test execution of the build derivation, the following attributes are of interest:
### `modRoot` {#var-go-modRoot}

- [`checkInputs`](#var-stdenv-checkInputs)
- [`preCheck`](#var-stdenv-preCheck)
- [`checkFlags`](#var-stdenv-checkFlags)
The root directory of the Go module that contains the `go.mod` file.

In addition to the above attributes, and the many more variables respected also by `stdenv.mkDerivation`, both `buildGoModule` and `buildGoPackage` respect Go-specific attributes that tweak them to behave slightly differently:
Defaults to `./`, which is the root of `src`.

### `ldflags` {#var-go-ldflags}

Expand Down Expand Up @@ -326,6 +213,38 @@ Whether the build result should be allowed to contain references to the Go tool

Defaults to `false`

## Overriding `goModules` {#buildGoModule-goModules-override}

Overriding `<pkg>.goModules` by calling `goModules.overrideAttrs` is unsupported. Still, it is possible to override the `vendorHash` (`goModules`'s `outputHash`) and the `pre`/`post` hooks for both the build and patch phases of the primary and `goModules` derivation.

Alternatively, the primary derivation provides an overridable `passthru.overrideModAttrs` function to store the attribute overlay implicitly taken by `goModules.overrideAttrs`. Here's an example usage of `overrideModAttrs`:

```nix
{
pet-overridden = pet.overrideAttrs (
finalAttrs: previousAttrs: {
passthru = previousAttrs.passthru // {
# If the original package has an `overrideModAttrs` attribute set, you'd
# want to extend it, and not replace it. Hence we use
# `lib.composeExtensions`. If you are sure the `overrideModAttrs` of the
# original package trivially does nothing, you can safely replace it
# with your own by not using `lib.composeExtensions`.
overrideModAttrs = lib.composeExtensions previousAttrs.passthru.overrideModAttrs (
finalModAttrs: previousModAttrs: {
# goModules-specific overriding goes here
postBuild = ''
# Here you have access to the `vendor` directory.
substituteInPlace vendor/github.com/example/repo/file.go \
--replace-fail "panic(err)" ""
'';
}
);
};
}
);
}
```

## Controlling the Go environment {#ssec-go-environment}

The Go build can be further tweaked by setting environment variables. In most cases, this isn't needed. Possible values can be found in the [Go documentation of accepted environment variables](https://pkg.go.dev/cmd/go#hdr-Environment_variables). Notice that some of these flags are set by the builder itself and should not be set explicitly. If in doubt, grep the implementation of the builder.
Expand Down Expand Up @@ -364,4 +283,23 @@ If a larger amount of tests should be skipped, the following pattern can be used
```

To disable tests altogether, set `doCheck = false;`.
`buildGoPackage` does not execute tests by default.

## Migrating from `buildGoPackage` to `buildGoModule` {#buildGoPackage-migration}

::: {.warning}
`buildGoPackage` was removed for the 25.05 release. It was used to build legacy Go programs
that do not support Go modules.
:::

Go modules, released 6y ago, are now widely adopted in the ecosystem.
Most upstream projects are using Go modules, and the tooling previously used for dependency management in Go is mostly deprecated, archived or at least unmaintained at this point.

In case a project doesn't have external dependencies or dependencies are vendored in a way understood by `go mod init`, migration can be done with a few changes in the package.

- Switch the builder from `buildGoPackage` to `buildGoModule`
- Remove `goPackagePath` and other attributes specific to `buildGoPackage`
- Set `vendorHash = null;`
- Run `go mod init <module name>` in `postPatch`

In case the package has external dependencies that aren't vendored or the build setup is more complex the upstream source might need to be patched.
Examples for the migration can be found in the [issue tracking migration withing nixpkgs](https://github.com/NixOS/nixpkgs/issues/318069).
30 changes: 17 additions & 13 deletions doc/redirects.json
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2721,29 +2721,20 @@
"index.html#ssec-language-go"
],
"buildgomodule-parameters": [
"index.html#buildgomodule-parameters"
"index.html#buildgomodule-parameters",
"index.html#ssec-go-common-attributes"
],
"ex-buildGoModule": [
"index.html#ex-buildGoModule"
],
"buildGoModule-vendorHash": [
"index.html#buildGoModule-vendorHash"
],
"buildGoModule-goModules-override": [
"index.html#buildGoModule-goModules-override"
],
"ssec-go-legacy": [
"index.html#ssec-go-legacy"
],
"buildGoPackage-migration": [
"index.html#buildGoPackage-migration"
],
"example-for-buildgopackage": [
"index.html#buildGoPackage-migration",
"index.html#ssec-go-legacy",
"index.html#example-for-buildgopackage"
],
"ssec-go-common-attributes": [
"index.html#ssec-go-common-attributes"
],
"var-go-ldflags": [
"index.html#var-go-ldflags"
],
Expand All @@ -2759,6 +2750,9 @@
"var-go-excludedPackages": [
"index.html#var-go-excludedPackages"
],
"var-go-proxyVendor": [
"index.html#var-go-proxyVendor"
],
"var-go-CGO_ENABLED": [
"index.html#var-go-CGO_ENABLED"
],
Expand All @@ -2768,6 +2762,16 @@
"var-go-allowGoReference": [
"index.html#var-go-allowGoReference"
],
"var-go-vendorHash": [
"index.html#var-go-vendorHash",
"index.html#buildGoModule-vendorHash"
],
"var-go-modPostBuild": [
"index.html#var-go-modPostBuild"
],
"var-go-modRoot": [
"index.html#var-go-modRoot"
],
"ssec-go-environment": [
"index.html#ssec-go-environment"
],
Expand Down
2 changes: 2 additions & 0 deletions nixos/doc/manual/release-notes/rl-2505.section.md
View file
Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,8 @@

<!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->

- `buildGoPackage` has been removed. Use `buildGoModule` instead. See the [Go section in the nixpkgs manual](https://nixos.org/manual/nixpkgs/unstable/#sec-language-go) for details.

- `kanata` was updated to v1.7.0, which introduces several breaking changes.
See the release notes of
[v1.7.0](https://github.com/jtroo/kanata/releases/tag/v1.7.0)
Expand Down
5 changes: 0 additions & 5 deletions pkgs/build-support/go/module.nix
View file
Original file line number Diff line number Diff line change
Expand Up @@ -46,9 +46,6 @@
# Meta data for the final derivation.
, meta ? { }

# Not needed with `buildGoModule`.
, goPackagePath ? ""

# Go linker flags.
, ldflags ? [ ]
# Go build flags.
Expand All @@ -61,8 +58,6 @@
, ...
}@args':

assert goPackagePath != "" -> throw "`goPackagePath` is not needed with `buildGoModule`";

let
args = removeAttrs args' [ "overrideModAttrs" "vendorSha256" ];

Expand Down
Loading

0 comments on commit 0ecc88f

Please sign in to comment.