Embed version string from leiningen project in application

Question

I want to be able to query or embed the version string set by the leiningen project and display that value to user. Uses include displaying the version string from the CLI, or as a header in a ring application. Is this possible?

Answer 1

If you're running inside Leiningen using lein run or the like, it's available as a system property: (System/getProperty "myproject.version"). If you're producing a jar you need to read pom.properties.

Answer 2

I like technomancy's answer, but I had to go look up how to "read pom.properties". It turns out that for the maven artifact com.example/my-project, there is a file on the classpath under

META-INF/maven/com.example/my-project/pom.properties

which you can read into a java.util.Properties and get out a "version" key.

(ns com.example.version
  (:require [clojure.java.io :as io])
  (:import (java.util Properties)))

(defn read-project-version [groupid artifact]
  (-> (doto (Properties.)
        (.load (-> "META-INF/maven/%s/%s/pom.properties"
                 (format groupid artifact)
                 (io/resource)
                 (io/reader))))
    (.get "version")))

Answer 3

Someone has written a nice library for handling this: https://github.com/trptcolin/versioneer

It works for lein projects, both running in lein and from an uberjar. Use it like the following (taken from the Github page):

Add this to your project.clj:

[trptcolin/versioneer "0.2.0"]

Then, in your code, do something like this, where GROUP-ID and ARTIFACT-ID are the usual Leiningen/Maven identifiers for your project.

user=> (require '[trptcolin.versioneer.core :as version])
nil
user=> (version/get-version "GROUP-ID" "ARTIFACT-ID")
"1.2.3-SNAPSHOT"

Answer 4

if you build a jar file you can extract the current version from the jar file.

otherwise if you are not doing AOT then you can read the project.clj file (because it's a map) and then extract the version.

I certainty hope there is a more elegant solution short of writing a leiningen plugin for this (unless someone else wants to write this, hint hint..)

Answer 5

Here is how I read my project name and version, note that the project.clj file is read during compilation and jar file simply contains the string:

(defmacro proj-version []
  (some->> (slurp "project.clj") clojure.edn/read-string (drop 1) (take 2) (str/join " ")))

(defn -main []
  (println (proj-version))

so for (defproject abc "1.2.3" ..., when you run -main it will print:

abc 1.2.3