Refactoring

Co-authored-by: Kieron Browne <[email protected]>
Co-authored-by: Julia Nedialkova <[email protected]>
Co-authored-by: Giuseppe Capizzi <[email protected]>

Author: 3 people

bpmchecker/bpmchecker.go

@@ -0,0 +1,56 @@
+package command
+
+import (
+	"context"
+	"errors"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+)
+
+type Collector struct {
+	cmd      string
+	filename string
+}
+
+func New(cmd, filename string) Collector {
+	return Collector{cmd: cmd, filename: filename}
+}
+
+func (c Collector) Run(ctx context.Context, destPath string, stdout io.Writer) error {
+	cmd := exec.CommandContext(ctx, "sh", "-c", c.cmd)
+	out, err := cmd.Output()
+
+	if ctx.Err() == context.DeadlineExceeded {
+		return ctx.Err()
+	}
+
+	if exitErr, ok := err.(*exec.ExitError); ok {
+		return errors.New(string(exitErr.Stderr))
+	}
+
+	if err != nil {
+		return err
+	}
+
+	outPath := filepath.Join(destPath, c.filename)
+
+	err = os.MkdirAll(filepath.Dir(outPath), 0755)
+	if err != nil {
+		return err
+	}
+
+	err = ioutil.WriteFile(outPath, out, 0644)
+	if err != nil {
+		return err
+	}
+
+	_, err = stdout.Write(out)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

bpmchecker/bpmchecker_suite_test.go

@@ -0,0 +1,97 @@
+package command_test
+
+import (
+	"context"
+	"io"
+	"io/ioutil"
+	"path/filepath"
+	"time"
+
+	"code.cloudfoundry.org/dontpanic/collectors/command"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"github.com/onsi/gomega/gbytes"
+)
+
+var _ = Describe("Command Runner", func() {
+	var (
+		cmd      string
+		ctx      context.Context
+		cancel   context.CancelFunc
+		dstPath  string
+		stdout   io.Writer
+		filename string
+
+		err error
+	)
+
+	BeforeEach(func() {
+		ctx = context.TODO()
+		dstPath, err = ioutil.TempDir("", "")
+		Expect(err).NotTo(HaveOccurred())
+		stdout = gbytes.NewBuffer()
+		filename = "hello"
+	})
+
+	JustBeforeEach(func() {
+		err = command.New(cmd, filename).Run(ctx, dstPath, stdout)
+	})
+
+	When("cmd is a simple executable", func() {
+		BeforeEach(func() {
+			cmd = "echo hello world"
+		})
+
+		It("returns the byte output", func() {
+			Expect(err).NotTo(HaveOccurred())
+			Expect(stdout).To(gbytes.Say("hello world\n"))
+
+			fileContents, err := ioutil.ReadFile(filepath.Join(dstPath, filename))
+			Expect(err).NotTo(HaveOccurred())
+			Expect(fileContents).To(Equal([]byte("hello world\n")))
+		})
+	})
+
+	When("cmd is a pipeline", func() {
+		BeforeEach(func() {
+			cmd = "seq 2 10 | wc -l"
+		})
+
+		It("executes the pipeline", func() {
+			Expect(err).NotTo(HaveOccurred())
+			Expect(stdout).To(gbytes.Say("9"))
+
+			fileContents, err := ioutil.ReadFile(filepath.Join(dstPath, filename))
+			Expect(err).NotTo(HaveOccurred())
+			Expect(fileContents).To(Equal([]byte("9\n")))
+		})
+	})
+
+	When("cmd exceeds time limit", func() {
+		BeforeEach(func() {
+			ctx, cancel = context.WithTimeout(context.Background(), time.Millisecond)
+			cmd = "sleep 1"
+		})
+
+		AfterEach(func() {
+			cancel()
+		})
+
+		It("times out", func() {
+			Expect(err).To(Equal(context.DeadlineExceeded))
+		})
+	})
+
+	When("command fails and has stdout and stderr", func() {
+		BeforeEach(func() {
+			cmd = "echo foo; echo bar >&2; exit 1"
+		})
+
+		It("returns error containing bar", func() {
+			Expect(err).To(MatchError(ContainSubstring("bar")))
+			Expect(filepath.Join(dstPath, filename)).NotTo(BeAnExistingFile())
+			Expect(stdout).NotTo(gbytes.Say("foo"))
+		})
+	})
+
+})