Add plugin tasks (#651)

pkg/plugin/raw.go

@@ -0,0 +1,122 @@
+package plugin
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os/exec"
+	"sync"
+
+	"github.com/stashapp/stash/pkg/logger"
+	"github.com/stashapp/stash/pkg/plugin/common"
+)
+
+type rawTaskBuilder struct{}
+
+func (*rawTaskBuilder) build(task pluginTask) Task {
+	return &rawPluginTask{
+		pluginTask: task,
+	}
+}
+
+type rawPluginTask struct {
+	pluginTask
+
+	started   bool
+	waitGroup sync.WaitGroup
+	cmd       *exec.Cmd
+	done      chan bool
+}
+
+func (t *rawPluginTask) Start() error {
+	if t.started {
+		return errors.New("task already started")
+	}
+
+	command := t.plugin.getExecCommand(t.operation)
+	if len(command) == 0 {
+		return fmt.Errorf("empty exec value in operation %s", t.operation.Name)
+	}
+
+	cmd := exec.Command(command[0], command[1:]...)
+
+	stdin, err := cmd.StdinPipe()
+	if err != nil {
+		return fmt.Errorf("error getting plugin process stdin: %s", err.Error())
+	}
+
+	go func() {
+		defer stdin.Close()
+
+		input := t.buildPluginInput()
+		inBytes, _ := json.Marshal(input)
+		io.WriteString(stdin, string(inBytes))
+	}()
+
+	stderr, err := cmd.StderrPipe()
+	if err != nil {
+		logger.Error("Plugin stderr not available: " + err.Error())
+	}
+
+	stdout, err := cmd.StdoutPipe()
+	if nil != err {
+		logger.Error("Plugin stdout not available: " + err.Error())
+	}
+
+	t.waitGroup.Add(1)
+	t.done = make(chan bool, 1)
+	if err = cmd.Start(); err != nil {
+		return fmt.Errorf("Error running plugin: %s", err.Error())
+	}
+
+	go t.handlePluginStderr(stderr)
+	t.cmd = cmd
+
+	// send the stdout to the plugin output
+	go func() {
+		defer t.waitGroup.Done()
+		defer close(t.done)
+		stdoutData, _ := ioutil.ReadAll(stdout)
+		stdoutString := string(stdoutData)
+
+		output := t.getOutput(stdoutString)
+
+		err := cmd.Wait()
+		if err != nil && output.Error == nil {
+			errStr := err.Error()
+			output.Error = &errStr
+		}
+
+		t.result = &output
+	}()
+
+	t.started = true
+	return nil
+}
+
+func (t *rawPluginTask) getOutput(output string) common.PluginOutput {
+	// try to parse the output as a PluginOutput json. If it fails just
+	// get the raw output
+	ret := common.PluginOutput{}
+	decodeErr := json.Unmarshal([]byte(output), &ret)
+
+	if decodeErr != nil {
+		ret.Output = &output
+	}
+
+	return ret
+}
+
+func (t *rawPluginTask) Wait() {
+	t.waitGroup.Wait()
+}
+
+func (t *rawPluginTask) Stop() error {
+	if t.cmd == nil {
+		return nil
+	}
+
+	return t.cmd.Process.Kill()
+}