Add logging

README.md

@@ -35,4 +35,12 @@ var (
 )
 ```
 This will embed the contents of the `sql` directory in your output binary file, making it easy to distribute those files.
-You can also use the `migrations` variable in place of the provider interface.
+You can also use the `migrations` variable in place of the provider interface.
+
+### Logging
+
+This library logs certain errors and information into a logger.
+By default, Logrus is used as a logger.
+This can be overwritten by assigning custom values to variables in `logger` package.
+
+Note that calling `LogPanic` expects the system to panic afterward, as not doing so might lead to unexpected results.

connection_handler.go

@@ -3,6 +3,7 @@ package gotabase
 import (
 	"database/sql"
 	"errors"
+	"github.com/KowalskiPiotr98/gotabase/logger"
 )
 
 var connection *connectionHandler
@@ -48,16 +49,20 @@ func InitialiseConnection(connectionString string, driver string) error {
 		return connectionAlreadyInitialised
 	}
 
+	logger.LogInfo("Initialising database connection...")
 	database, err := sql.Open(driver, connectionString)
 	if err != nil {
+		logger.LogWarn("Failed to open database connection: %v", err)
 		return err
 	}
 	err = database.Ping()
 	if err != nil {
+		logger.LogWarn("Failed to ping database: %v", err)
 		database.Close()
 		return err
 	}
 
+	logger.LogInfo("Database connection established")
 	connection = &connectionHandler{
 		database: database,
 	}
@@ -66,19 +71,20 @@ func InitialiseConnection(connectionString string, driver string) error {
 
 func GetConnection() Connector {
 	if connection == nil {
-		panic("database connection not initialised")
+		logger.LogPanic(connectionNotInitialisedErr.Error())
 	}
 
 	return connection
 }
 
 func BeginTransaction() (*Transaction, error) {
 	if connection == nil {
-		panic("database connection not initialised")
+		logger.LogPanic(connectionNotInitialisedErr.Error())
 	}
 
 	tx, err := connection.database.Begin()
 	if err != nil {
+		logger.LogWarn("Failed to begin transaction: %v", err)
 		return nil, err
 	}
 	return newTransaction(tx), nil
@@ -90,6 +96,7 @@ func CloseConnection() error {
 	}
 
 	if err := connection.database.Close(); err != nil {
+		logger.LogWarn("Failed to close database connection: %v", err)
 		return err
 	}
 	connection = nil

go.mod

@@ -1,3 +1,7 @@
 module github.com/KowalskiPiotr98/gotabase
 
-go 1.21.0
+go 1.21.0
+
+require github.com/sirupsen/logrus v1.9.3
+
+require golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8 // indirect

go.sum

@@ -1,2 +1,15 @@
-github.com/lib/pq v1.10.9 h1:YXG7RB+JIjhP29X+OtkiDnYaXQwpS4JEWq7dtCCRUEw=
-github.com/lib/pq v1.10.9/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
+github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8 h1:0A+M6Uqn+Eje4kHMK80dtF3JCXC4ykBgQG4Fe06QRhQ=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

logger/log.go

@@ -0,0 +1,11 @@
+package logger
+
+import (
+	log "github.com/sirupsen/logrus"
+)
+
+var (
+	LogInfo  = log.Infof
+	LogWarn  = log.Warnf
+	LogPanic = log.Panicf
+)

migrations/provider.go

@@ -3,6 +3,7 @@ package migrations
 import (
 	"errors"
 	"fmt"
+	"github.com/KowalskiPiotr98/gotabase/logger"
 	"slices"
 	"strconv"
 	"strings"
@@ -23,6 +24,7 @@ func getLatestAvailableMigration(migrations MigrationFileProvider) (int, error)
 func getMigrationSql(migrations MigrationFileProvider, i int) (string, error) {
 	fileBytes, err := migrations.ReadFile(fmt.Sprintf("sql/%d.sql", i))
 	if err != nil {
+		logger.LogWarn("Unable to read migration file: %v", err)
 		return "", migrationNotFound
 	}
 	return string(fileBytes), nil
@@ -31,6 +33,7 @@ func getMigrationSql(migrations MigrationFileProvider, i int) (string, error) {
 func getAvailableMigrations(migrations MigrationFileProvider) (*[]int, error) {
 	dirContents, err := migrations.ReadDir("sql")
 	if err != nil {
+		logger.LogWarn("Unable to read migration directory: %v", err)
 		return nil, migrationNotFound
 	}
 
@@ -39,6 +42,7 @@ func getAvailableMigrations(migrations MigrationFileProvider) (*[]int, error) {
 		nameString := strings.TrimPrefix(strings.TrimSuffix(file.Name(), ".sql"), "sql/")
 		nameInt, err := strconv.Atoi(nameString)
 		if err != nil {
+			logger.LogWarn("Unable to parse migration file name: %v", err)
 			return nil, err
 		}
 		available = append(available, nameInt)

migrations/runner.go

@@ -3,6 +3,7 @@ package migrations
 import (
 	"fmt"
 	database "github.com/KowalskiPiotr98/gotabase"
+	"github.com/KowalskiPiotr98/gotabase/logger"
 	"strings"
 )
 
@@ -25,13 +26,16 @@ func Migrate(connector database.Connector, fileProvider MigrationFileProvider) e
 	latestApplied, err := getLatestAppliedMigration(connector)
 	if err != nil {
 		if !IsInitialMigrationError(err) {
+			logger.LogWarn("Unable to get latest applied migration: %v", err)
 			return err
 		}
 		latestApplied = -1
 	}
 
 	latestAvailable, err := getLatestAvailableMigration(fileProvider)
+	logger.LogInfo("Latest applied migration: %d, latest available migration: %d", latestApplied, latestAvailable)
 	if latestApplied == latestAvailable {
+		logger.LogInfo("Latest migration is already applied, nothing to do.")
 		return nil
 	}
 
@@ -42,12 +46,15 @@ func Migrate(connector database.Connector, fileProvider MigrationFileProvider) e
 			return err
 		}
 
+		logger.LogInfo("Applying migration %d", currentMigration)
 		_, err = connector.Exec(MigrationCreator(migrationSql, currentMigration))
 		if err != nil {
+			logger.LogWarn("Unable to execute migration %d: %v", currentMigration, err)
 			return err
 		}
 		currentMigration++
 	}
+	logger.LogInfo("All pending migrations applied.")
 	return nil
 }