From 72eddf4258db8c10b145ded188d13c50e4a5530b Mon Sep 17 00:00:00 2001
From: Sebastiaan van Stijn <github@gone.nl>
Date: Wed, 29 Mar 2017 13:44:14 +0200
Subject: [PATCH] Refactor "init" version parsing, and add unit-test

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
---
 daemon/info_unix.go      | 50 +++++++++++++++++++++-----------------
 daemon/info_unix_test.go | 52 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 80 insertions(+), 22 deletions(-)
 create mode 100644 daemon/info_unix_test.go

diff --git a/daemon/info_unix.go b/daemon/info_unix.go
index ddbd7523d5..56437acdb0 100644
--- a/daemon/info_unix.go
+++ b/daemon/info_unix.go
@@ -11,6 +11,7 @@ import (
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/dockerversion"
 	"github.com/docker/docker/pkg/sysinfo"
+	"github.com/pkg/errors"
 )
 
 // FillPlatformInfo fills the platform related info.
@@ -54,32 +55,37 @@ func (daemon *Daemon) FillPlatformInfo(v *types.Info, sysInfo *sysinfo.SysInfo)
 		v.RuncCommit.ID = "N/A"
 	}
 
-	v.InitCommit.Expected = dockerversion.InitCommitID
 	if rv, err := exec.Command(DefaultInitBinary, "--version").Output(); err == nil {
-		// examples of how Tini outputs version info:
-		//   "tini version 0.13.0 - git.949e6fa"
-		//   "tini version 0.13.2"
-		parts := strings.Split(strings.TrimSpace(string(rv)), " - ")
+		ver, err := parseInitVersion(string(rv))
 
-		v.InitCommit.ID = ""
-		if v.InitCommit.ID == "" && len(parts) >= 2 {
-			gitParts := strings.Split(parts[1], ".")
-			if len(gitParts) == 2 && gitParts[0] == "git" {
-				v.InitCommit.ID = gitParts[1]
-				v.InitCommit.Expected = dockerversion.InitCommitID[0:len(v.InitCommit.ID)]
-			}
-		}
-		if v.InitCommit.ID == "" && strings.HasPrefix(parts[0], "tini version") {
-			vs := strings.TrimPrefix(parts[0], "tini version ")
-			v.InitCommit.ID = "v" + vs
-		}
-
-		if v.InitCommit.ID == "" {
-			logrus.Warnf("failed to retrieve %s version: unknown output format: %s", DefaultInitBinary, string(rv))
-			v.InitCommit.ID = "N/A"
+		if err != nil {
+			logrus.Warnf("failed to retrieve %s version: %s", DefaultInitBinary, err)
 		}
+		v.InitCommit = ver
 	} else {
-		logrus.Warnf("failed to retrieve %s version", DefaultInitBinary)
+		logrus.Warnf("failed to retrieve %s version: %s", DefaultInitBinary, err)
 		v.InitCommit.ID = "N/A"
 	}
 }
+
+// parseInitVersion parses a Tini version string, and extracts the version.
+func parseInitVersion(v string) (types.Commit, error) {
+	version := types.Commit{ID: "", Expected: dockerversion.InitCommitID}
+	parts := strings.Split(strings.TrimSpace(v), " - ")
+
+	if len(parts) >= 2 {
+		gitParts := strings.Split(parts[1], ".")
+		if len(gitParts) == 2 && gitParts[0] == "git" {
+			version.ID = gitParts[1]
+			version.Expected = dockerversion.InitCommitID[0:len(version.ID)]
+		}
+	}
+	if version.ID == "" && strings.HasPrefix(parts[0], "tini version ") {
+		version.ID = "v" + strings.TrimPrefix(parts[0], "tini version ")
+	}
+	if version.ID == "" {
+		version.ID = "N/A"
+		return version, errors.Errorf("unknown output format: %s", v)
+	}
+	return version, nil
+}
diff --git a/daemon/info_unix_test.go b/daemon/info_unix_test.go
new file mode 100644
index 0000000000..ef36c40e39
--- /dev/null
+++ b/daemon/info_unix_test.go
@@ -0,0 +1,52 @@
+// +build !windows
+
+package daemon
+
+import (
+	"testing"
+
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/dockerversion"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestParseInitVersion(t *testing.T) {
+	tests := []struct {
+		version string
+		result  types.Commit
+		invalid bool
+	}{
+		{
+			version: "tini version 0.13.0 - git.949e6fa",
+			result:  types.Commit{ID: "949e6fa", Expected: dockerversion.InitCommitID[0:7]},
+		}, {
+			version: "tini version 0.13.0\n",
+			result:  types.Commit{ID: "v0.13.0", Expected: dockerversion.InitCommitID},
+		}, {
+			version: "tini version 0.13.2",
+			result:  types.Commit{ID: "v0.13.2", Expected: dockerversion.InitCommitID},
+		}, {
+			version: "tini version0.13.2",
+			result:  types.Commit{ID: "N/A", Expected: dockerversion.InitCommitID},
+			invalid: true,
+		}, {
+			version: "",
+			result:  types.Commit{ID: "N/A", Expected: dockerversion.InitCommitID},
+			invalid: true,
+		}, {
+			version: "hello world",
+			result:  types.Commit{ID: "N/A", Expected: dockerversion.InitCommitID},
+			invalid: true,
+		},
+	}
+
+	for _, test := range tests {
+		ver, err := parseInitVersion(string(test.version))
+		if test.invalid {
+			assert.Error(t, err)
+		} else {
+			assert.NoError(t, err)
+		}
+		assert.Equal(t, test.result, ver)
+	}
+}