fix: sum256 the container name so derivations do not overflow (#191)

For instance, the volume name derived from the workflow name may exceed the file system limit when the container name it is derived from is too long.

Fixes forgejo/runner#152

Reviewed-on: https://code.forgejo.org/forgejo/act/pulls/191
Reviewed-by: Michael Kriese <michael.kriese@gmx.de>
Co-authored-by: Earl Warren <contact@earl-warren.org>
Co-committed-by: Earl Warren <contact@earl-warren.org>

act/common/sha256.go

@@ -0,0 +1,13 @@
+// Copyright 2025 The Forgejo Authors
+// SPDX-License-Identifier: MIT
+package common
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+)
+
+func Sha256(content string) string {
+	hashBytes := sha256.Sum256([]byte(content))
+	return hex.EncodeToString(hashBytes[:])
+}

act/common/sha256_test.go

@@ -0,0 +1,13 @@
+// Copyright 2025 The Forgejo Authors
+// SPDX-License-Identifier: MIT
+package common
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSha256(t *testing.T) {
+	assert.Equal(t, "3fc9b689459d738f8c88a3a48aa9e33542016b7a4052e001aaa536fca74813cb", Sha256("something"))
+}

act/model/workflow.go

@@ -1,8 +1,6 @@
 package model
 
 import (
-	"crypto/sha256"
-	"encoding/hex"
 	"errors"
 	"fmt"
 	"io"
@@ -738,8 +736,7 @@ func (s *Step) Type() StepType {
 }
 
 func (s *Step) UsesHash() string {
-	hashBytes := sha256.Sum256([]byte(s.Uses))
-	hashString := hex.EncodeToString(hashBytes[:])
+	hashString := common.Sha256(s.Uses)
 	return filepath.Join(hashString[:2], hashString[2:])
 }
 

act/runner/run_context.go

@@ -94,7 +94,7 @@ func (rc *RunContext) GetEnv() map[string]string {
 }
 
 func (rc *RunContext) jobContainerName() string {
-	return createSimpleContainerName(rc.Config.ContainerNamePrefix, "WORKFLOW-"+rc.Run.Workflow.Name, "JOB-"+rc.Name)
+	return createSimpleContainerName(rc.Config.ContainerNamePrefix, "WORKFLOW-"+common.Sha256(rc.Run.Workflow.Name), "JOB-"+rc.Name)
 }
 
 // networkName return the name of the network which will be created by `act` automatically for job,