chore(ci): add golangci-lint

.github/workflows/lint.yml

@@ -0,0 +1,22 @@
+name: lint
+
+on:
+  pull_request:
+
+jobs:
+  run-linters:
+    name: Run linters
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@c85c95e3d7251135ab7dc9ce3241c5835cc595a9 # v3.5.3
+
+      - name: Set up Go
+        uses: actions/setup-go@fac708d6674e30b6ba41289acaab6d4b75aa0753 # v4.0.1
+        with:
+          go-version-file: 'go.mod'
+
+      - name: Run linters
+        uses: golangci/golangci-lint-action@639cd343e1d3b897ff35927a75193d57cfcba299 # v3.6.0
+        with:
+          version: latest

.golangci.yml

@@ -0,0 +1,78 @@
+# Copyright (c) HashiCorp, Inc.
+# SPDX-License-Identifier: MPL-2.0
+
+linters:
+  disable-all: true
+  enable:
+    - gofmt
+    - govet
+    - unconvert
+    - staticcheck
+    - ineffassign
+    - unparam
+    - forbidigo
+    - gomodguard
+    - gosimple
+
+issues:
+  # Disable the default exclude list so that all excludes are explicitly
+  # defined in this file.
+  exclude-use-default: false
+
+  exclude-rules:
+    # Temp Ignore SA9004: only the first constant in this group has an explicit type
+    # https://staticcheck.io/docs/checks#SA9004
+    - linters: [staticcheck]
+      text: "SA9004:"
+
+    - linters: [staticcheck]
+      text: 'SA1019: "io/ioutil" has been deprecated since Go 1.16'
+
+    # An argument that always receives the same value is often not a problem.
+    - linters: [unparam]
+      text: "always receives"
+
+    # Often functions will implement an interface that returns an error without
+    # needing to return an error. Sometimes the error return value is unnecessary
+    # but a linter can not tell the difference.
+    - linters: [unparam]
+      text: 'result \d+ \(error\) is always nil'
+
+    # Allow unused parameters to start with an underscore. Arguments with a name
+    # of '_' are already ignored.
+    # Ignoring longer names that start with underscore allow for better
+    # self-documentation than a single underscore by itself.  Underscore arguments
+    # should generally only be used when a function is implementing an interface.
+    - linters: [unparam]
+      text: "`_[^`]*` is unused"
+
+    # Temp ignore some common unused parameters so that unparam can be added
+    # incrementally.
+    - linters: [unparam]
+      text: "`(t|resp|req|entMeta)` is unused"
+
+linters-settings:
+  govet:
+    check-shadowing: true
+    enable-all: true
+    disable:
+      - fieldalignment
+      - nilness
+      - shadow
+      - unusedwrite
+  forbidigo:
+    # Forbid the following identifiers (list of regexp).
+    forbid:
+      - '\bioutil\b(# Use io and os packages instead of ioutil)?'
+      - '\brequire\.New\b(# Use package-level functions with explicit TestingT)?'
+      - '\bassert\.New\b(# Use package-level functions with explicit TestingT)?'
+    # Exclude godoc examples from forbidigo checks.
+    # Default: true
+    exclude_godoc_examples: false
+  gofmt:
+    simplify: true
+
+run:
+  timeout: 10m
+  concurrency: 4
+  skip-dirs-use-default: false