toil: use pre-commit to maintain properly formatted imports (#17940)

pro-tip: you can skip this check with `git commit --no-verify` to override

.pre-commit-config.yaml

@@ -0,0 +1,39 @@
+# Copyright (c) HashiCorp, Inc.
+# SPDX-License-Identifier: BUSL-1.1
+
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+repos:
+-   repo: https://github.com/tekwizely/pre-commit-golang
+    rev: v1.0.0-rc.1
+    hooks:
+    # Formats go imports into deterministic sections
+    # `pre-commit run gci` to run in isolation
+    -   id: my-cmd
+        name: gci
+        # skip all generated go files
+        exclude: |
+            (?x)(
+                ^proto-public/|
+                ^proto/|
+                ^agent/xds/z_xds_packages\.go$|
+                ^testing/deployer/topology/default_versions\.go$|
+                \.deepcopy\.go$|
+                \.gen\.go$|
+                \.pb\.go$|
+                \.pb\.binary\.go$|
+                generated_funcs\.go$|
+                _generated_test\.go$|
+                mock_.+\.go$
+            )
+        args:
+        - "gci"
+        - "write"
+        - "--section"
+        - "standard"
+        - "--section"
+        - "default"
+        - "--section"
+        - "prefix(github.com/hashicorp/)"
+        - "--section"
+        - "prefix(github.com/hashicorp/consul/)"

Makefile

@@ -14,12 +14,14 @@ GOLANGCI_LINT_VERSION='v1.51.1'
 MOCKERY_VERSION='v2.20.0'
 BUF_VERSION='v1.26.0'
 
-PROTOC_GEN_GO_GRPC_VERSION="v1.2.0"
+PROTOC_GEN_GO_GRPC_VERSION='v1.2.0'
 MOG_VERSION='v0.4.1'
 PROTOC_GO_INJECT_TAG_VERSION='v1.3.0'
-PROTOC_GEN_GO_BINARY_VERSION="v0.1.0"
+PROTOC_GEN_GO_BINARY_VERSION='v0.1.0'
 DEEP_COPY_VERSION='bc3f5aa5735d8a54961580a3a24422c308c831c2'
 COPYWRITE_TOOL_VERSION='v0.16.4'
+# Go imports formatter
+GCI_VERSION='v0.11.2'
 
 MOCKED_PB_DIRS= pbdns
 

build-support/scripts/devtools.sh

@@ -25,6 +25,7 @@ Options:
     -protobuf                Just install tools for protobuf.
     -lint                    Just install tools for linting.
     -codegen                 Just install tools for codegen.
+    -pre-commit              Just install pre-commit.
     -h | --help              Print this help text.
 EOF
 }
@@ -51,6 +52,10 @@ function main {
                 codegen_install
                 return 0
                 ;;
+            -pre-commit )
+                pre_commit_install
+                return 0
+                ;;
             -h | --help )
                 usage
                 return 0
@@ -139,6 +144,9 @@ function lint_install {
     local golangci_lint_version
     golangci_lint_version="$(make --no-print-directory print-GOLANGCI_LINT_VERSION)"
 
+    local gci_version
+    gci_version="$(make --no-print-directory print-GCI_VERSION)"
+
     install_unversioned_tool \
         'lint-consul-retry' \
         'github.com/hashicorp/lint-consul-retry@master'
@@ -152,6 +160,12 @@ function lint_install {
         'github.com/golangci/golangci-lint' \
         "${golangci_lint_version}" \
         'github.com/golangci/golangci-lint/cmd/golangci-lint'
+
+    install_versioned_tool \
+        'gci' \
+        'github.com/daixiang0/gci' \
+        "${gci_version}" \
+        'github.com/daixiang0/gci'
 }
 
 function codegen_install {
@@ -181,11 +195,50 @@ function copywrite_install {
         'github.com/hashicorp/copywrite'
 }
 
-function tools_install {
+function pre_commit_install {
+    # if already installed make sure the hook is also installed
+    if command -v "pre-commit" &>/dev/null; then
+        # Not to be confused with installing the tool, this installs
+        # the git hook locally (.git/hooks/pre-commit) which pre-commit
+        # uses as a vector to run checks on `git commit`. This hook is
+        # generated based on the local environment hence not source
+        # controlled.
+        pre-commit install
+        return 0
+    fi
+
+    # Install options based on https://pre-commit.com/#installation
+    if command -v "brew" &>/dev/null; then
+        brew install pre-commit && pre-commit install
+        return 0
+    fi
 
+    # Try python regardless of platform (mac, linux, etc)
+    if command -v "pip3" &>/dev/null; then
+        pip3 install pre-commit && pre-commit install
+        return 0
+    fi
+
+    # Can't disappoint the linux/debian folks
+    if command -v "apt" &>/dev/null; then
+        sudo apt-get install -yq pre-commit && pre-commit install
+        return 0
+    fi
+
+    if [[ "$(uname)" == "Darwin" ]]; then
+        echo "ERROR: Install homebrew from https://brew.sh/ so that pre-commit (https://pre-commit.com) can be installed."
+        return 1
+    fi
+
+    echo "ERROR: Install python3 and pip3 so that pre-commit (https://pre-commit.com) can be installed."
+    return 1
+}
+
+function tools_install {
     lint_install
     proto_tools_install
     codegen_install
+    pre_commit_install
     copywrite_install
 
     return 0