add documentation about S3 container, fix S3 configration

docs/middleware/torrent_approval.md

@@ -28,6 +28,11 @@ There are two sources of hashes: `list` and `directory`.
   files at start and then periodically watch for new files to add, or for delete events
   to remove hash from storage.
 
+* `s3` will search for torrent files in specified S3-compatible storage (AWS S3, MinIO, etc.) and
+  append/delete records from storage. This source will parse all existing
+  files at start and then periodically watch for new files to add, or for delete events
+  to remove hash from storage.
+
 Note: if storage is not `memory`, and `preserve` option set to `true`, records
 will be persisted in storage until _somebody_ or _something_ (different tool with access
 to storage) won't delete it.
@@ -48,7 +53,21 @@ If `name` is empty or `internal` global storage will be used
 	- `directory`:
 		- `path` - directory to watch
         - `period` - time between two directory checks
-		- `invert` and `storage_ctx` has the same meanins as `list`'s options
+		- `invert` and `storage_ctx` has the same meaning as `list`'s options
+	- `s3`:
+		- `endpoint`* - base URL of S3 provider
+        - `region`* - S3 region to connect to
+        - `key_id`* - S3 access key ID
+        - `key_secret`* - S3 secret access key
+		- `session_token`* - S3 temporary security credential
+        - `bucket` - S3 bucket
+        - `prefix` - prefix path to search entries
+        - `suffix` - suffix to filter returned entries, such as extension (e.g. `.torrent`)
+		- `period` - time between two S3 checks
+		- `invert` and `storage_ctx` has the same meaning as `list`'s options
+
+Note: `s3` options marked with `*` and any other specific options can be omitted in MoChi and can be provided 
+with environment variables or in `$HOME/.aws/*` files (see [AWS SDK documentation](https://docs.aws.amazon.com/sdk-for-go/v2/developer-guide/configure-gosdk.html)).
 
 Configuration example:
 

middleware/torrentapproval/container/s3/s3.go

@@ -5,6 +5,7 @@ package s3
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"iter"
@@ -34,9 +35,9 @@ type Config struct {
 	list.Config
 	Endpoint     string
 	Region       string
-	KeyID        string
-	KeySecret    string
-	SessionToken string
+	KeyID        string `cfg:"key_id"`
+	KeySecret    string `cfg:"key_secret"`
+	SessionToken string `cfg:"session_token"`
 	Bucket       string
 	Prefix       string
 	Suffix       string
@@ -52,6 +53,11 @@ func build(conf conf.MapConfig, st storage.DataStorage) (container.Container, er
 	if err := conf.Unmarshal(c); err != nil {
 		return nil, fmt.Errorf("unable to deserialise configuration: %w", err)
 	}
+
+	if len(c.Bucket) == 0 {
+		return nil, errors.New("no bucket provided")
+	}
+
 	if c.Period == 0 {
 		logger.Warn().
 			Str("name", "Period").
@@ -61,25 +67,35 @@ func build(conf conf.MapConfig, st storage.DataStorage) (container.Container, er
 		c.Period = defaultPeriod
 	}
 
-	awsCfg, err := config.LoadDefaultConfig(context.Background())
-	if err != nil {
-		return nil, fmt.Errorf("unable load AWS S3 SDK configuration: %w", err)
-	}
+	modifiers := make([]func(*config.LoadOptions) error, 1, 4)
 
-	awsCfg.Logger = logging.LoggerFunc(func(classification logging.Classification, format string, v ...interface{}) {
+	modifiers[0] = config.WithLogger(logging.LoggerFunc(func(
+		classification logging.Classification, format string, v ...interface{},
+	) {
 		if classification == logging.Debug {
 			logger.Debug().CallerSkipFrame(1).Msg(fmt.Sprintf(format, v...))
 		} else if classification == logging.Warn {
 			logger.Warn().CallerSkipFrame(1).Msg(fmt.Sprintf(format, v...))
 		}
-	})
+	}))
 
 	if len(c.Endpoint) > 0 {
-		awsCfg.BaseEndpoint = &c.Endpoint
+		modifiers = append(modifiers, config.WithBaseEndpoint(c.Endpoint))
 	}
 
 	if len(c.Region) > 0 {
-		awsCfg.Region = c.Region
+		modifiers = append(modifiers, config.WithRegion(c.Endpoint))
+	}
+
+	if len(c.KeyID) > 0 || len(c.KeySecret) > 0 || len(c.SessionToken) > 0 {
+		modifiers = append(modifiers, config.WithCredentialsProvider(
+			credentials.NewStaticCredentialsProvider(c.KeyID, c.KeySecret, c.SessionToken)),
+		)
+	}
+
+	awsCfg, err := config.LoadDefaultConfig(context.Background(), modifiers...)
+	if err != nil {
+		return nil, fmt.Errorf("unable load AWS S3 SDK configuration: %w", err)
 	}
 
 	if len(c.KeyID) > 0 || len(c.KeySecret) > 0 || len(c.SessionToken) > 0 {

middleware/torrentapproval/container/s3/s3_test.go

@@ -57,7 +57,7 @@ emDE8BsT0R1/0GVl`),
 }
 
 func init() {
-	_ = log.ConfigureLogger("", "debug", false, false)
+	_ = log.ConfigureLogger("", "warn", false, false)
 }
 
 type mockS3 struct {