Add golangci-lint to project (hashicorp#8686)

* Add golangci-lint as linting tool

* Disable failing staticchecks to start; GitHub issue to handle coming soon

* Run `goimports -w` to repair all source files that have improperly
formatted imports

* makefile: Add ci-lint target to run on travis

This change adds a new make target for running golangci-lint on newly
added Go files only. This target is expected to run during Packer ci builds.

* .github/contributing: Add code linting instructions

* travis: Update job configuration to run parallel builds

.github/CONTRIBUTING.md

@@ -259,6 +259,28 @@ localized code generation. Say you are working on the Amazon builder: running
 `go generate ./builder/amazon/...` will do that for you. Make sure that the
 latest code generation tool is installed by running `make install-gen-deps`.
 
+#### Code linting
+
+Packer relies on [golangci-lint](https://github.com/golangci/golangci-lint) for linting its Go code base, excluding any generated code created by `go generate`. Linting is executed on new files during Travis builds via `make ci`; the linting of existing code base is only executed when running `make lint`. Linting a large project like Packer is an iterative process so existing code base will have issues that are actively being fixed; pull-requests that fix existing linting issues are always welcomed :smile:.
+
+The main configuration for golangci-lint is the `.golangci.yml` in the project root. See `golangci-lint --help` for a list of flags that can be used to override the default configuration.
+
+Run golangci-lint on the entire Packer code base.
+```
+make lint
+```
+
+Run golangci-lint on a single pkg or directory; PKG_NAME expands to /builder/amazon/...
+```
+make lint PKG_NAME=builder/amazon
+```
+
+Note: linting on Travis uses the `--new-from-rev=origin/master` flag to only lint new files added within a branch or pull-request. To run this check locally you can use the `ci-lint` make target. See [golangci-lint in CI](https://github.com/golangci/golangci-lint#faq) for more information.
+
+```
+make ci-lint
+```
+
 #### Running Unit Tests
 
 You can run tests for individual packages using commands like this:

.golangci.yml

@@ -0,0 +1,124 @@
+issues:
+  # List of regexps of issue texts to exclude, empty list by default.
+  # But independently from this option we use default exclude patterns,
+  # it can be disabled by `exclude-use-default: false`. To list all
+  # excluded by default patterns execute `golangci-lint run --help`
+
+  exclude-rules:
+    # Exclude gosimple bool check
+    - linters:
+      - gosimple
+      text: "S(1002|1008|1021)"
+    # Exclude failing staticchecks for now
+    - linters:
+        - staticcheck
+      text: "SA(1006|1019|4006|4010|4017|5007|6005|9004):"
+    # Exclude lll issues for long lines with go:generate
+    - linters:
+        - lll
+      source: "^//go:generate "
+
+  # Maximum issues count per one linter. Set to 0 to disable. Default is 50.
+  max-issues-per-linter: 0
+
+  # Maximum count of issues with the same text. Set to 0 to disable. Default is 3.
+  max-same-issues: 0
+
+linters:
+  disable-all: true
+  enable:
+    - deadcode
+    - errcheck
+    - goimports
+    - gosimple
+    - govet
+    - ineffassign
+    - staticcheck
+    - unconvert
+    - unused
+    - varcheck
+  fast: true
+
+# options for analysis running
+run:
+  # default concurrency is a available CPU number
+  concurrency: 4
+
+  # timeout for analysis, e.g. 30s, 5m, default is 1m
+  timeout: 10m
+
+  # exit code when at least one issue was found, default is 1
+  issues-exit-code: 1
+
+  # include test files or not, default is true
+  tests: true
+
+  # list of build tags, all linters use it. Default is empty list.
+  #build-tags:
+  #  - mytag
+
+  # which dirs to skip: issues from them won't be reported;
+  # can use regexp here: generated.*, regexp is applied on full path;
+  # default value is empty list, but default dirs are skipped independently
+  # from this option's value (see skip-dirs-use-default).
+  #skip-dirs:
+  #  - src/external_libs
+  #  - autogenerated_by_my_lib
+
+  # default is true. Enables skipping of directories:
+  #   vendor$, third_party$, testdata$, examples$, Godeps$, builtin$
+  skip-dirs-use-default: true
+
+  # which files to skip: they will be analyzed, but issues from them
+  # won't be reported. Default value is empty list, but there is
+  # no need to include all autogenerated files, we confidently recognize
+  # autogenerated files. If it's not please let us know.
+  skip-files:
+    - ".*\\.hcl2spec\\.go$"
+  #  - lib/bad.go
+
+  # by default isn't set. If set we pass it to "go list -mod={option}". From "go help modules":
+  # If invoked with -mod=readonly, the go command is disallowed from the implicit
+  # automatic updating of go.mod described above. Instead, it fails when any changes
+  # to go.mod are needed. This setting is most useful to check that go.mod does
+  # not need updates, such as in a continuous integration and testing system.
+  # If invoked with -mod=vendor, the go command assumes that the vendor
+  # directory holds the correct copies of dependencies and ignores
+  # the dependency descriptions in go.mod.
+  modules-download-mode: vendor
+
+
+# output configuration options
+output:
+  # colored-line-number|line-number|json|tab|checkstyle|code-climate, default is "colored-line-number"
+  format: colored-line-number
+
+  # print lines of code with issue, default is true
+  print-issued-lines: true
+
+  # print linter name in the end of issue text, default is true
+  print-linter-name: true
+
+  # make issues output unique by line, default is true
+  uniq-by-line: true
+
+
+# all available settings of specific linters
+linters-settings:
+ errcheck:
+    # report about not checking of errors in type assetions: `a := b.(MyStruct)`;
+    # default is false: such cases aren't reported by default.
+    check-type-assertions: false
+
+    # report about assignment of errors to blank identifier: `num, _ := strconv.Atoi(numStr)`;
+    # default is false: such cases aren't reported by default.
+    check-blank: false
+
+    # [deprecated] comma-separated list of pairs of the form pkg:regex
+    # the regex is used to ignore names within pkg. (default "fmt:.*").
+    # see https://github.com/kisielk/errcheck#the-deprecated-method for details
+    ignore: fmt:.*,io/ioutil:^Read.*,io:Close
+
+    # path to a file containing a list of functions to exclude from checking
+    # see https://github.com/kisielk/errcheck#excluding-functions for details
+    #exclude: /path/to/file.txt

.travis.yml

@@ -4,20 +4,21 @@ env:
 os:
   - osx
 
-sudo: false
-
 language: go
 
-go:
-  - 1.13.x
-
-script:
-  - df -h
-  - travis_wait make ci
-
 branches:
   only:
     - master
 
-matrix:
+jobs:
   fast_finish: true
+  include:
+    - go: "1.13.x"
+      name: "go test"
+      script:
+        - df -h
+        - travis_wait make ci
+    - go: "1.13.x"
+      name: "go lint"
+      script: travis_wait make ci-lint
+

Makefile

@@ -18,7 +18,8 @@ GOLDFLAGS=-X $(GIT_IMPORT).GitCommit=$(GIT_COMMIT)$(GIT_DIRTY)
 
 export GOLDFLAGS
 
-.PHONY: bin checkversion ci default install-build-deps install-gen-deps fmt fmt-docs fmt-examples generate releasebin test testacc testrace
+.PHONY: bin checkversion ci ci-lint default install-build-deps install-gen-deps fmt fmt-docs fmt-examples generate install-lint-deps lint \
+	releasebin test testacc testrace
 
 default: install-build-deps install-gen-deps generate testrace dev releasebin package dev fmt fmt-check mode-check fmt-docs fmt-examples
 
@@ -49,12 +50,16 @@ install-gen-deps: ## Install dependencies for code generation
 	# dir. `go get` will change our deps and the following deps are not part of
 	# out code dependencies; so a go mod tidy will remove them again. `go
 	# install` seems to install the last tagged version and we want to install
-	# master. 
+	# master.
 	@(cd $(TEMPDIR) && GO111MODULE=on go get github.com/mna/pigeon@master)
 	@(cd $(TEMPDIR) && GO111MODULE=on go get github.com/alvaroloes/enumer@master)
 	@go install ./cmd/struct-markdown
 	@go install ./cmd/mapstructure-to-hcl2
 
+install-lint-deps: ## Install linter dependencies
+	@echo "==> Updating linter dependencies..."
+	@curl -sSfL -q https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(GOPATH)/bin v1.23.1
+
 dev: ## Build and install a development build
 	@grep 'const VersionPrerelease = ""' version/version.go > /dev/null ; if [ $$? -eq 0 ]; then \
 		echo "ERROR: You must add prerelease tags to version/version.go prior to making a dev build."; \
@@ -66,6 +71,20 @@ dev: ## Build and install a development build
 	@cp $(GOPATH)/bin/packer bin/packer
 	@cp $(GOPATH)/bin/packer pkg/$(GOOS)_$(GOARCH)
 
+lint: install-lint-deps ## Lint Go code
+	@if [ ! -z  $(PKG_NAME) ]; then \
+		echo "golangci-lint run ./$(PKG_NAME)/..."; \
+		golangci-lint run ./$(PKG_NAME)/...; \
+	else \
+		echo "golangci-lint run"; \
+		golangci-lint run; \
+	fi
+
+ci-lint: install-lint-deps ## On ci only lint newly added Go source files
+	@echo "==> Running linter on newly added Go source files..."
+	GO111MODULE=on golangci-lint run --new-from-rev=origin/master
+
+
 fmt: ## Format Go code
 	@go fmt ./...
 

builder/amazon/chroot/builder.go

@@ -10,11 +10,11 @@ package chroot
 import (
 	"context"
 	"errors"
-	"github.com/hashicorp/packer/builder"
 	"runtime"
 
 	"github.com/aws/aws-sdk-go/service/ec2"
 	"github.com/hashicorp/hcl/v2/hcldec"
+	"github.com/hashicorp/packer/builder"
 	awscommon "github.com/hashicorp/packer/builder/amazon/common"
 	"github.com/hashicorp/packer/common"
 	"github.com/hashicorp/packer/common/chroot"

builder/amazon/chroot/step_mount_device.go

@@ -4,13 +4,13 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"github.com/hashicorp/packer/builder"
 	"log"
 	"os"
 	"path/filepath"
 	"strings"
 
 	"github.com/aws/aws-sdk-go/service/ec2"
+	"github.com/hashicorp/packer/builder"
 	"github.com/hashicorp/packer/common"
 	"github.com/hashicorp/packer/helper/multistep"
 	"github.com/hashicorp/packer/packer"

builder/amazon/chroot/step_prepare_device.go

@@ -3,10 +3,10 @@ package chroot
 import (
 	"context"
 	"fmt"
-	"github.com/hashicorp/packer/builder"
 	"log"
 	"os"
 
+	"github.com/hashicorp/packer/builder"
 	"github.com/hashicorp/packer/helper/multistep"
 	"github.com/hashicorp/packer/packer"
 )

builder/amazon/common/interpolate_build_info_test.go

@@ -1,12 +1,12 @@
 package common
 
 import (
-	"github.com/hashicorp/packer/builder"
 	"reflect"
 	"testing"
 
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/service/ec2"
+	"github.com/hashicorp/packer/builder"
 	"github.com/hashicorp/packer/helper/multistep"
 )
 

builder/amazon/common/step_modify_ami_attributes.go

@@ -3,6 +3,7 @@ package common
 import (
 	"context"
 	"fmt"
+
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/session"
 	"github.com/aws/aws-sdk-go/service/ec2"

builder/amazon/ebs/builder.go

@@ -11,6 +11,7 @@ package ebs
 import (
 	"context"
 	"fmt"
+
 	"github.com/aws/aws-sdk-go/service/ec2"
 	"github.com/aws/aws-sdk-go/service/iam"
 	"github.com/hashicorp/hcl/v2/hcldec"

builder/amazon/ebssurrogate/builder.go

@@ -9,6 +9,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+
 	"github.com/aws/aws-sdk-go/service/ec2"
 	"github.com/aws/aws-sdk-go/service/iam"
 	"github.com/hashicorp/hcl/v2/hcldec"

builder/amazon/ebssurrogate/builder_test.go

@@ -1,9 +1,10 @@
 package ebssurrogate
 
 import (
-	"github.com/hashicorp/packer/builder/amazon/common"
 	"testing"
 
+	"github.com/hashicorp/packer/builder/amazon/common"
+
 	"github.com/hashicorp/packer/packer"
 )
 

builder/amazon/instance/builder.go

@@ -9,13 +9,13 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"github.com/hashicorp/packer/builder"
 	"os"
 	"strings"
 
 	"github.com/aws/aws-sdk-go/service/ec2"
 	"github.com/aws/aws-sdk-go/service/iam"
 	"github.com/hashicorp/hcl/v2/hcldec"
+	"github.com/hashicorp/packer/builder"
 	awscommon "github.com/hashicorp/packer/builder/amazon/common"
 	"github.com/hashicorp/packer/common"
 	"github.com/hashicorp/packer/helper/communicator"

builder/generated_data_test.go

@@ -1,8 +1,9 @@
 package builder
 
 import (
-	"github.com/hashicorp/packer/helper/multistep"
 	"testing"
+
+	"github.com/hashicorp/packer/helper/multistep"
 )
 
 func TestGeneratedData_Put(t *testing.T) {

builder/lxc/step_provision.go

@@ -2,9 +2,9 @@ package lxc
 
 import (
 	"context"
-	"github.com/hashicorp/packer/common"
 	"log"
 
+	"github.com/hashicorp/packer/common"
 	"github.com/hashicorp/packer/helper/multistep"
 	"github.com/hashicorp/packer/packer"
 )

builder/lxd/step_provision.go

@@ -2,9 +2,9 @@ package lxd
 
 import (
 	"context"
-	"github.com/hashicorp/packer/common"
 	"log"
 
+	"github.com/hashicorp/packer/common"
 	"github.com/hashicorp/packer/helper/multistep"
 	"github.com/hashicorp/packer/packer"
 )

builder/osc/chroot/step_chroot_provision.go

@@ -2,9 +2,9 @@ package chroot
 
 import (
 	"context"
-	"github.com/hashicorp/packer/common"
 	"log"
 
+	"github.com/hashicorp/packer/common"
 	"github.com/hashicorp/packer/helper/multistep"
 	"github.com/hashicorp/packer/packer"
 )

builder/parallels/common/ssh_config.go

@@ -1,9 +1,10 @@
 package common
 
 import (
+	"time"
+
 	"github.com/hashicorp/packer/helper/communicator"
 	"github.com/hashicorp/packer/template/interpolate"
-	"time"
 )
 
 // SSHConfig contains the configuration for SSH communicator.