Pull request: 2276 no golangci

Merge in DNS/adguard-home from 2276-no-golangci to master

Updates #2276.

Squashed commit of the following:

commit 81a5a62716b8c57e8575cf149938cd941660b6f5
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Dec 8 16:59:19 2020 +0300

    all: fix Makefile

commit a8f2546803a3986f1292b45921c27409366bc04a
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Dec 8 16:11:09 2020 +0300

    all: remove golangci-yaml, add new linters

scripts/go-install-tools.sh

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+test "$VERBOSE" = '1' && set -x
+set -e -f -u
+
+# TODO(a.garipov): Add goconst?
+
+env GOBIN="${PWD}/bin" "$GO" install --modfile=./internal/tools/go.mod\
+	github.com/fzipp/gocyclo/cmd/gocyclo\
+	github.com/golangci/misspell/cmd/misspell\
+	github.com/gordonklaus/ineffassign\
+	github.com/kisielk/errcheck\
+	github.com/kyoh86/looppointer/cmd/looppointer\
+	github.com/securego/gosec/v2/cmd/gosec\
+	golang.org/x/lint/golint\
+	golang.org/x/tools/go/analysis/passes/nilness/cmd/nilness\
+	golang.org/x/tools/go/analysis/passes/shadow/cmd/shadow\
+	honnef.co/go/tools/cmd/staticcheck\
+	mvdan.cc/gofumpt\
+	mvdan.cc/unparam\
+	;

scripts/go-lint.sh

@@ -0,0 +1,95 @@
+#!/bin/sh
+
+# Verbosity levels:
+#   0 = Don't print anything except for errors.
+#   1 = Print commands, but not nested commands.
+#   2 = Print everything.
+test "${VERBOSE:=0}" -gt '0' && set -x
+
+# Set $EXITONERROR to zero to see all errors.
+test "${EXITONERROR:=1}" = '0' && set +e || set -e
+
+# We don't need glob expansions and we want to see errors about unset
+# variables.
+set -f -u
+
+# blocklistimports is a simple check against unwanted packages.
+# Currently it only looks for package log which is replaced by our own
+# package github.com/AdguardTeam/golibs/log.
+blocklistimports () {
+	git grep -F -e '"log"' -- '*.go' || exit 0;
+}
+
+# underscores is a simple check against Go filenames with underscores.
+underscores () {
+	git ls-files '*_*.go' | { grep -F -e '_darwin.go' \
+		-e '_freebsd.go' -e '_linux.go' -e '_others.go' \
+		-e '_test.go' -e '_unix.go' -e '_windows.go' \
+		-v || exit 0; }
+}
+
+# exitonoutput exits with a nonzero exit code if there is anything in
+# the command's combined output.
+exitonoutput() {
+	test "$VERBOSE" -lt '2' && set +x
+
+	cmd="$1"
+	shift
+
+	exitcode='0'
+	output="$("$cmd" "$@" 2>&1)"
+	if [ "$output" != '' ]
+	then
+		if [ "$*" != '' ]
+		then
+			echo "combined output of '$cmd $@':"
+		else
+			echo "combined output of '$cmd':"
+		fi
+
+		echo "$output"
+
+		exitcode='1'
+	fi
+
+	test "$VERBOSE" -gt '0' && set -x
+
+	return "$exitcode"
+}
+
+exitonoutput blocklistimports
+
+exitonoutput underscores
+
+exitonoutput gofumpt --extra -l -s .
+
+golint --set_exit_status ./...
+
+"$GO" vet ./...
+
+gocyclo --over 20 .
+
+gosec --quiet .
+
+ineffassign .
+
+unparam ./...
+
+misspell --error ./...
+
+looppointer ./...
+
+nilness ./...
+
+# TODO(a.garipov): Enable shadow after fixing all of the shadowing.
+# shadow --strict ./...
+
+# TODO(a.garipov): Enable errcheck fully after handling all errors,
+# including the deferred ones, properly.  Also, perhaps, enable --blank.
+# errcheck ./...
+exitonoutput sh -c '
+	errcheck --asserts ./... |\
+		{ grep -e "defer" -e "_test\.go:" -v || exit 0; }
+'
+
+staticcheck --checks='all' ./...