[+] improve "build" GHA workflow

.github/workflows/build.yml

@@ -30,70 +30,20 @@ jobs:
       uses: actions/setup-go@v6
       with:
         go-version: '1.25'
+        cache-dependency-path: 'go.sum'
 
-    - name: Cache Go modules
-      uses: actions/cache@v4
-      with:
-        path: |
-          ~/.cache/go-build
-          ~/go/pkg/mod
-        key: ${{ runner.os }}-go-1.25-${{ hashFiles('**/go.sum') }}
-        restore-keys: |
-          ${{ runner.os }}-go-1.25-
-          ${{ runner.os }}-go-
-
-    - name: Download dependencies
-      run: go mod download
+    - name: Build
+      run: go build ./cmd/etcd_fdw
 
-    - name: Verify dependencies
-      run: go mod verify
+    - name: GolangCI-Lint
+      uses: golangci/golangci-lint-action@v8
+      with:
+        version: latest      
 
     - name: Run tests
       run: go test -v -race -coverprofile=coverage.out ./...
-      # Note: Integration tests run via testcontainers (no separate services needed)
-
-    - name: Upload coverage to Codecov
-      uses: codecov/codecov-action@v5
-      with:
-        file: ./coverage.out
-        flags: unittests
-        name: codecov-umbrella
-
-  build:
-    name: Build
-    runs-on: ubuntu-latest
-    needs: test
 
-    steps:
-    - name: Check out code
-      uses: actions/checkout@v5
-
-    - name: Set up Go
-      uses: actions/setup-go@v6
-      with:
-        go-version: '1.25'
-
-    - name: Build binary
-      run: go build -v ./cmd/etcd_fdw
-
-    - name: Test binary execution
-      run: ./etcd_fdw --version
-
-  lint:
-    name: Lint
-    runs-on: ubuntu-latest
-
-    steps:
-    - name: Check out code
-      uses: actions/checkout@v5
-
-    - name: Set up Go
-      uses: actions/setup-go@v6
-      with:
-        go-version: '1.25'
-
-    - name: Run golangci-lint
-      uses: golangci/golangci-lint-action@v8
+    - name: Coveralls
+      uses: coverallsapp/github-action@v2
       with:
-        version: latest
-        args: --timeout=5m
+        file: coverage.out 

.golangci.yml

@@ -1,43 +1,30 @@
-version: 2
-
-run:
-  timeout: 5m
-
+version: "2"
 linters:
   enable:
-    - errcheck
-    - govet
-    - ineffassign
-    - staticcheck
-    - unused
-    - goconst
     - gocyclo
     - misspell
-    - dupl
-    - unconvert
-    - whitespace
     - revive
-
-linters-settings:
-  gocyclo:
-    min-complexity: 15
-  dupl:
-    threshold: 100
-  goconst:
-    min-len: 2
-    min-occurrences: 2
-  misspell:
-    locale: US
-  revive:
+  settings:
+    gocyclo:
+      min-complexity: 15
+  exclusions:
+    generated: lax
+    presets:
+      - comments
+      - common-false-positives
+      - legacy
+      - std-error-handling
     rules:
-      - name: exported
-        disabled: true
-
-issues:
-  exclude-rules:
-    - path: _test\.go
-      linters:
-        - goconst
-    - path: cmd/
-      linters:
-        - gocyclo
+      - path: (.+)\.go$
+        text: SA5008   # ignore staticcheck for go-flags
+    paths:
+      - third_party$
+      - builtin$
+      - examples$
+formatters:
+  exclusions:
+    generated: lax
+    paths:
+      - third_party$
+      - builtin$
+      - examples$

cmd/etcd_fdw/cli_test.go

@@ -2,7 +2,6 @@
 package main
 
 import (
-	"os"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -125,12 +124,8 @@ func TestCLIParsing(t *testing.T) {
 // TestCLIEnvironmentVariables tests that CLI can read from environment variables
 func TestCLIEnvironmentVariables(t *testing.T) {
 	// Set environment variables
-	os.Setenv("ETCD_FDW_POSTGRES_DSN", "postgres://env:pass@localhost:5432/envdb")
-	os.Setenv("ETCD_FDW_ETCD_DSN", "etcd://localhost:2379,localhost:2380/")
-	defer func() {
-		os.Unsetenv("ETCD_FDW_POSTGRES_DSN")
-		os.Unsetenv("ETCD_FDW_ETCD_DSN")
-	}()
+	t.Setenv("ETCD_FDW_POSTGRES_DSN", "postgres://env:pass@localhost:5432/envdb")
+	t.Setenv("ETCD_FDW_ETCD_DSN", "etcd://localhost:2379,localhost:2380/")
 
 	// This will fail because ParseCLI function doesn't exist yet
 	config, err := ParseCLI([]string{})
@@ -144,12 +139,8 @@ func TestCLIEnvironmentVariables(t *testing.T) {
 // TestCLIFlagPrecedence tests that command-line flags override environment variables
 func TestCLIFlagPrecedence(t *testing.T) {
 	// Set environment variables
-	os.Setenv("ETCD_FDW_POSTGRES_DSN", "postgres://env:pass@localhost:5432/envdb")
-	os.Setenv("ETCD_FDW_ETCD_DSN", "etcd://localhost:2379/")
-	defer func() {
-		os.Unsetenv("ETCD_FDW_POSTGRES_DSN")
-		os.Unsetenv("ETCD_FDW_ETCD_DSN")
-	}()
+	t.Setenv("ETCD_FDW_POSTGRES_DSN", "postgres://env:pass@localhost:5432/envdb")
+	t.Setenv("ETCD_FDW_ETCD_DSN", "etcd://localhost:2379/")
 
 	// Command-line flags should override environment
 	args := []string{

cmd/etcd_fdw/main.go

@@ -144,7 +144,7 @@ func main() {
 	if err != nil {
 		logrus.WithError(err).Fatal("Failed to connect to etcd after retries")
 	}
-	defer etcdClient.Close()
+	defer func() { _ = etcdClient.Close() }()
 
 	// Parse polling interval
 	pollingInterval, err := time.ParseDuration(config.PollingInterval)

internal/log/formatter.go

@@ -1,3 +1,4 @@
+// Package log provides a custom logrus formatter
 package log
 
 import (
@@ -11,6 +12,7 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+// NewFormatter creates a new custom logrus formatter
 func NewFormatter(noColors bool) *Formatter {
 	return &Formatter{
 		HideKeys: false,

internal/migrations/migrations_test.go

@@ -69,7 +69,7 @@ func TestMigrationWithRealDatabase(t *testing.T) {
 	ctx := context.Background()
 	conn, err := pgx.Connect(ctx, dsn)
 	require.NoError(t, err, "Should connect to test database")
-	defer conn.Close(ctx)
+	defer func() { _ = conn.Close(ctx) }()
 
 	// Apply migrations
 	err = Apply(ctx, conn) // Use the Apply function instead of migrator method
@@ -102,7 +102,7 @@ func TestMigrationFunctions(t *testing.T) {
 	ctx := context.Background()
 	conn, err := pgx.Connect(ctx, dsn)
 	require.NoError(t, err, "Should connect to test database")
-	defer conn.Close(ctx)
+	defer func() { _ = conn.Close(ctx) }()
 
 	// Apply migrations first
 	err = Apply(ctx, conn)
@@ -163,7 +163,7 @@ func getTestDSN(t *testing.T) string {
 
 	// Cleanup container when test ends
 	t.Cleanup(func() {
-		pgContainer.Terminate(ctx)
+		_ = pgContainer.Terminate(ctx)
 	})
 
 	// Get connection string

internal/sync/etcd.go

@@ -54,7 +54,7 @@ func (c *EtcdClient) WatchPrefix(ctx context.Context, startRevision int64) clien
 		opts = append(opts, clientv3.WithRev(startRevision+1))
 	}
 
-	watchChan := c.Client.Watch(ctx, c.prefix, opts...)
+	watchChan := c.Watch(ctx, c.prefix, opts...)
 	logrus.WithFields(logrus.Fields{
 		"prefix":   c.prefix,
 		"revision": startRevision,
@@ -65,7 +65,7 @@ func (c *EtcdClient) WatchPrefix(ctx context.Context, startRevision int64) clien
 
 // GetAllKeys retrieves all key-value pairs with the given prefix for initial sync
 func (c *EtcdClient) GetAllKeys(ctx context.Context, prefix string) ([]KeyValueRecord, error) {
-	resp, err := c.Client.Get(ctx, prefix, clientv3.WithPrefix(), clientv3.WithSort(clientv3.SortByKey, clientv3.SortAscend))
+	resp, err := c.Get(ctx, prefix, clientv3.WithPrefix(), clientv3.WithSort(clientv3.SortByKey, clientv3.SortAscend))
 	if err != nil {
 		return nil, fmt.Errorf("failed to get all keys: %w", err)
 	}
@@ -90,59 +90,6 @@ func (c *EtcdClient) GetAllKeys(ctx context.Context, prefix string) ([]KeyValueR
 	return pairs, nil
 }
 
-// Put stores a key-value pair in etcd
-func (c *EtcdClient) Put(ctx context.Context, key, value string) (*clientv3.PutResponse, error) {
-	resp, err := c.Client.Put(ctx, key, value)
-	if err != nil {
-		return nil, fmt.Errorf("failed to put key %s: %w", key, err)
-	}
-
-	logrus.WithFields(logrus.Fields{
-		"key":      key,
-		"revision": resp.Header.Revision,
-	}).Debug("Put key to etcd")
-
-	return resp, nil
-}
-
-// Delete removes a key from etcd
-func (c *EtcdClient) Delete(ctx context.Context, key string) (*clientv3.DeleteResponse, error) {
-	resp, err := c.Client.Delete(ctx, key)
-	if err != nil {
-		return nil, fmt.Errorf("failed to delete key %s: %w", key, err)
-	}
-
-	logrus.WithFields(logrus.Fields{
-		"key":      key,
-		"revision": resp.Header.Revision,
-		"deleted":  resp.Deleted,
-	}).Debug("Deleted key from etcd")
-
-	return resp, nil
-}
-
-// Get retrieves a single key from etcd
-func (c *EtcdClient) Get(ctx context.Context, key string) (*KeyValueRecord, error) {
-	resp, err := c.Client.Get(ctx, key)
-	if err != nil {
-		return nil, fmt.Errorf("failed to get key %s: %w", key, err)
-	}
-
-	if len(resp.Kvs) == 0 {
-		return nil, nil // Key not found
-	}
-
-	kv := resp.Kvs[0]
-	value := string(kv.Value)
-
-	return &KeyValueRecord{
-		Key:       string(kv.Key),
-		Value:     value,
-		Revision:  kv.ModRevision,
-		Tombstone: false,
-	}, nil
-}
-
 // NewEtcdClientWithRetry creates a new etcd client with retry logic
 func NewEtcdClientWithRetry(ctx context.Context, dsn string) (*EtcdClient, error) {
 	config := DefaultRetryConfig()
@@ -158,7 +105,7 @@ func NewEtcdClientWithRetry(ctx context.Context, dsn string) (*EtcdClient, error
 		// Test the connection
 		if _, testErr := client.Get(ctx, "healthcheck"); testErr != nil {
 			if client != nil {
-				client.Close()
+				_ = client.Close()
 			}
 			return testErr
 		}
@@ -243,7 +190,7 @@ func (c *EtcdClient) WatchWithRecovery(ctx context.Context, startRevision int64)
 }
 
 // RetryEtcdOperation retries an etcd operation with exponential backoff
-func RetryEtcdOperation(ctx context.Context, operation func() error, operationName string) error {
+func RetryEtcdOperation(ctx context.Context, operation func() error) error {
 	config := DefaultRetryConfig()
 	return RetryWithBackoff(ctx, config, operation)
 }

internal/sync/integration_test.go

@@ -87,9 +87,9 @@ func setupTestContainers(t *testing.T) (*pgxpool.Pool, *EtcdClient, func()) {
 
 	cleanup := func() {
 		pool.Close()
-		etcdClient.Close()
-		pgContainer.Terminate(ctx)
-		etcdContainer.Terminate(ctx)
+		_ = etcdClient.Close()
+		_ = pgContainer.Terminate(ctx)
+		_ = etcdContainer.Terminate(ctx)
 	}
 
 	return pool, etcdClient, cleanup

internal/sync/postgresql.go

@@ -196,12 +196,6 @@ func NewWithRetry(ctx context.Context, databaseURL string, callbacks ...func(*pg
 	return pool, nil
 }
 
-// RetryOperation retries a database operation with exponential backoff
-func RetryOperation(ctx context.Context, operation func() error, operationName string) error {
-	config := DefaultRetryConfig()
-	return RetryWithBackoff(ctx, config, operation)
-}
-
 // InsertPendingRecord inserts a new record with revision -1 (pending sync to etcd)
 func InsertPendingRecord(ctx context.Context, pool PgxIface, key string, value string, tombstone bool) error {
 	query := `

internal/sync/sync.go

@@ -10,8 +10,6 @@ import (
 	clientv3 "go.etcd.io/etcd/client/v3"
 )
 
-const InvalidRevision = -1
-
 // Service orchestrates bidirectional synchronization between etcd and PostgreSQL
 type Service struct {
 	pgPool          PgxIface
@@ -140,8 +138,6 @@ func (s *Service) syncEtcdToPostgreSQL(ctx context.Context) error {
 				if err != nil {
 					logrus.WithError(err).WithField("key", string(event.Kv.Key)).Error("Failed to process etcd event after retries")
 					// Continue processing other events rather than failing entirely
-				} else {
-					latestRevision = event.Kv.ModRevision
 				}
 			}
 		}
@@ -261,7 +257,7 @@ func (s *Service) processPendingRecord(ctx context.Context, record KeyValueRecor
 			}
 			newRevision = resp.Header.Revision
 			return nil
-		}, "etcd_delete")
+		})
 
 		if err != nil {
 			logrus.WithError(err).WithFields(logrus.Fields{
@@ -284,7 +280,7 @@ func (s *Service) processPendingRecord(ctx context.Context, record KeyValueRecor
 			}
 			newRevision = resp.Header.Revision
 			return nil
-		}, "etcd_put")
+		})
 
 		if err != nil {
 			logrus.WithError(err).WithFields(logrus.Fields{