ci: bump shfmt to 3.5.1, simplify CI setup

1. Bump shfmt to v3.5.1. Release notes:
   https://github.com/mvdan/sh/releases

2. Since shfmt v3.5.0, specifying -l bash (or -l bats) is no longer
   necessary. Therefore, we can use shfmt -f to get the list of all
   shell files, and supply the list as an argument to shfmt.

3. Use shfmt docker image, so that we don't have to install anything
   explicitly. This greatly simplifies the shfmt CI job. Add
   localshfmt target so developers can still use a local shfmt binary
   when necessary.

Unfortunately, we can't use shfmt -f together with Docker (unless we run
not one but two containers, that is), so let's use git ls-files and a
couple of greps to find out all shell files.

Signed-off-by: Kir Kolyshkin <[email protected]>

.github/workflows/validate.yml

@@ -67,22 +67,6 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
     - uses: actions/checkout@v3
-    - name: vars
-      run: |
-        echo "VERSION=3.3.1" >> $GITHUB_ENV
-        echo "$(go env GOPATH)/bin" >> $GITHUB_PATH
-    - name: cache go mod and $GOCACHE
-      uses: actions/[email protected]
-      with:
-        path: |
-          ~/go/pkg/mod
-          ~/.cache/go-build
-        key: ${{ runner.os }}-shfmt-${{ env.VERSION }}
-        restore-keys: ${{ runner.os }}-shfmt-
-    - name: install shfmt
-      run: |
-        command -v shfmt || \
-          (cd ~ && GO111MODULE=on time go get mvdan.cc/sh/v3/cmd/shfmt@v$VERSION)
     - name: shfmt
       run: make shfmt
 

Makefile

@@ -164,11 +164,14 @@ shellcheck:
 		man/*.sh script/*
 	# TODO: add shellcheck for more sh files (contrib/completions/bash/runc).
 
+shfmt localshfmt: SH_SRC=$(shell git ls-files | grep -v ^vendor/ | grep -E '(.sh|.bash|.bats|bash/runc)$$')
 shfmt:
-	shfmt -ln bats -d -w tests/integration/*.bats
-	shfmt -ln bash -d -w man/*.sh script/* \
-		tests/*.sh tests/integration/*.bash tests/fuzzing/*.sh \
-		contrib/completions/bash/runc contrib/cmd/seccompagent/*.sh
+	$(CONTAINER_ENGINE) run $(CONTAINER_ENGINE_RUN_FLAGS) \
+		--rm -v $(CURDIR):/src -w /src \
+		mvdan/shfmt:v3.5.1 -d -w $(SH_SRC)
+
+localshfmt:
+	shfmt -d -w $(SH_SRC)
 
 vendor:
 	$(GO) mod tidy
@@ -184,5 +187,5 @@ verify-dependencies: vendor
 	localrelease dbuild lint man runcimage \
 	test localtest unittest localunittest integration localintegration \
 	rootlessintegration localrootlessintegration shell install install-bash \
-	install-man clean cfmt shfmt shellcheck \
+	install-man clean cfmt shfmt localshfmt shellcheck \
 	vendor verify-dependencies