Make agent usable for external backends (#3270)

cmd/agent/core/config_test.go

@@ -0,0 +1,61 @@
+// Copyright 2023 Woodpecker Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package core
+
+import (
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestReadAgentIDFileNotExists(t *testing.T) {
+	assert.EqualValues(t, -1, readAgentConfig("foobar.conf").AgentID)
+}
+
+func TestReadAgentIDFileExists(t *testing.T) {
+	tmpF, errTmpF := os.CreateTemp("", "tmp_")
+	if !assert.NoError(t, errTmpF) {
+		return
+	}
+	defer os.Remove(tmpF.Name())
+
+	// there is an existing config
+	errWrite := os.WriteFile(tmpF.Name(), []byte(`{"agent_id":3}`), 0o644)
+	if !assert.NoError(t, errWrite) {
+		return
+	}
+
+	// read existing config
+	actual := readAgentConfig(tmpF.Name())
+	assert.EqualValues(t, AgentConfig{3}, actual)
+
+	// update existing config and check
+	actual.AgentID = 33
+	_ = writeAgentConfig(actual, tmpF.Name())
+	actual = readAgentConfig(tmpF.Name())
+	assert.EqualValues(t, 33, actual.AgentID)
+
+	tmpF2, errTmpF := os.CreateTemp("", "tmp_")
+	if !assert.NoError(t, errTmpF) {
+		return
+	}
+	defer os.Remove(tmpF2.Name())
+
+	// write new config
+	_ = writeAgentConfig(actual, tmpF2.Name())
+	actual = readAgentConfig(tmpF2.Name())
+	assert.EqualValues(t, 33, actual.AgentID)
+}