Add source version to executable

The output of `git describe --dirty --always` is passed as a string via
Go build flags.

1 files changed, 13 insertions, 0 deletions

diff --git a/version.go b/version.go
new file mode 100644
index 0000000..c3cc266
--- /dev/null
+++ b/version.go
@@ -0,0 +1,13 @@
+package main
+
+import "fmt"
+
+var gitDescribe string
+
+func version() (string, error) {
+	if gitDescribe == "" {
+		return "", fmt.Errorf("No version information available")
+	}
+
+	return gitDescribe, nil
+}