Add golangci-lint to CI and resolve warnings

Signed-off-by: Austin Vazquez <[email protected]>

.github/workflows/main.yml

@@ -5,6 +5,10 @@ on:
   push:
     branches:
       - master
+
+env:
+  GO_VERSION: 1.20.x
+
 jobs:
   project:
     name: Project Checks
@@ -13,7 +17,7 @@ jobs:
     steps:
     - uses: actions/setup-go@v3
       with:
-        go-version: 1.19.x
+        go-version: ${{ env.GO_VERSION }}
     - uses: actions/checkout@v3
       with:
         path: src/github.com/containerd/fuse-overlayfs-snapshotter
@@ -22,6 +26,25 @@ jobs:
       with:
         working-directory: src/github.com/containerd/fuse-overlayfs-snapshotter
 
+  linters:
+    name: Linters
+    permissions:
+      contents: read # for actions/checkout to fetch code
+      pull-requests: read # for golangci/golangci-lint-action to fetch pull requests
+    runs-on: ubuntu-22.04
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          path: src/github.com/containerd/fuse-overlayfs-snapshotter
+      - uses: actions/setup-go@v3
+        with:
+          go-version: ${{ env.GO_VERSION }}
+      - uses: golangci/golangci-lint-action@v3
+        with:
+          version: v1.51.1
+          working-directory: src/github.com/containerd/fuse-overlayfs-snapshotter
+
   test:
     runs-on: ubuntu-22.04
     timeout-minutes: 30
@@ -41,6 +64,6 @@ jobs:
     steps:
     - uses: actions/setup-go@v3
       with:
-        go-version: 1.19.x
+        go-version: ${{ env.GO_VERSION }}
     - uses: actions/checkout@v3
     - run: make artifacts

.github/workflows/release.yml

@@ -4,16 +4,19 @@ on:
     tags:
     - 'v*'
     - 'test-action-release-*'
+
 env:
   GO111MODULE: on
+  GO_VERSION: 1.20.x
+
 jobs:
   release:
     runs-on: ubuntu-22.04
     timeout-minutes: 20
     steps:
     - uses: actions/setup-go@v3
       with:
-        go-version: 1.19.x
+        go-version: ${{ env.GO_VERSION }}
     - uses: actions/checkout@v3
       with:
         path: go/src/github.com/containerd/fuse-overlayfs-snapshotter

.golangci.yml

@@ -0,0 +1,26 @@
+linters:
+  enable:
+    - depguard
+    - exportloopref
+    - gofmt
+    - gosec
+    - ineffassign
+    - misspell
+    - nolintlint
+    - revive
+    - staticcheck
+    - tenv
+    - unconvert
+    - unused
+    - vet
+  disable:
+    - errcheck
+
+linters-settings:
+  depguard:
+    list-type: denylist
+    include-go-root: true
+    packages:
+      # use "io" or "os" instead
+      # https://go.dev/doc/go1.16#ioutil
+      - io/ioutil

fuseoverlayfs.go

@@ -103,7 +103,12 @@ func (o *snapshotter) Stat(ctx context.Context, key string) (snapshots.Info, err
 	if err != nil {
 		return snapshots.Info{}, err
 	}
-	defer t.Rollback()
+	defer func() {
+		if err := t.Rollback(); err != nil {
+			logger := log.G(ctx)
+			logger.Errorf("Error on transaction rollback: %v", err)
+		}
+	}()
 	_, info, _, err := storage.GetInfo(ctx, key)
 	if err != nil {
 		return snapshots.Info{}, err
@@ -120,7 +125,10 @@ func (o *snapshotter) Update(ctx context.Context, info snapshots.Info, fieldpath
 
 	info, err = storage.UpdateInfo(ctx, info, fieldpaths...)
 	if err != nil {
-		t.Rollback()
+		rollbackErr := t.Rollback()
+		if rollbackErr != nil {
+			return snapshots.Info{}, fmt.Errorf("%w: error on rollback: %w", err, rollbackErr)
+		}
 		return snapshots.Info{}, err
 	}
 
@@ -182,6 +190,9 @@ func (o *snapshotter) Mounts(ctx context.Context, key string) ([]mount.Mount, er
 		return nil, err
 	}
 	s, err := storage.GetSnapshot(ctx, key)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get snapshot %s from storage: %w", key, err)
+	}
 	_, info, _, err := storage.GetInfo(ctx, key)
 	t.Rollback()
 	if err != nil {