How to create a basic project setup using sbt-native-packager - sbt

I have a project setup working with SBT to the point of creating sub-project artifacts.
I have been searching for a way to create a JAR file that contains sub-project JAR files along with some meta information. Based on suggestions, I looked at sbt-native-packager and it seems to have the capabilities I need.
I am wondering if someone would be willing to help me along this path by providing tips on creating a skeleton package specification for the plugin.
I think my configuration is pretty simple.
What I want to end up with is a JAR file with the following contents:
/manifest.xml
module.xml
modules/sub-project-one.jar
sub-project-two.jar
sub-project-three.jar
Both the manifest.xml and module.xml files will be generated from project information. The name of the resulting JAR file will be based on the name of the root project, it's version and a suffix "nkp.jar" (e.g. overlay-1.0.1.nkp.jar).
Thanks in advance for any help getting me going with this.
-- Randy

Here's the basics of what you want:
val createManifestXml = taskKey[File]("Creates the packaged maniest.xml")
val createModuleXml = taskKey[File]("Creates the module.xml file.")
// TODO - Define createManifestXml + createModuleXml
mappings in Universal ++= {
Map(createManifestXml.value -> "manifest.xml"
module.xml -> "module.xml")
}
mappings in Universal ++= {
val moduleJars =
Seq((packageBin in subProjectOne).value,
(packageBin in subProjectTwo).value,
(packageBin in subProjectThree).value)
moduleJars map { jar =>
jar -> s"module/${jar.getName}"
}
}
This will insure that the tgz/txz/zip can be generated. You can then either use the "generic" universal -> msi and universal -> rpm/deb mappings or create that mapping by hand if you desire.
Hope that helps!

Related

How to publish an artifact with pom-packaging in SBT?

I have a multi-project build in SBT where some projects should aggregate dependencies and contain no code. So then clients could depend on these projects as a single dependency instead of directly depending on all of their aggregated dependencies. With Maven, this is a common pattern, e.g. when using Spring Boot.
In SBT, I figured I can suppress the generation of the empty artifacts by adding this setting to these projects:
packagedArtifacts := Classpaths.packaged(Seq(makePom)).value
However, the makePom task writes <packaging>jar</packaging> in the generated POM. But now that there is no JAR anymore, this should read <packaging>pom</packaging> instead.
How can I do this?
This question is a bit old, but I just came across the same issue and found a solution. The original answer does point to the right page where this info can be found, but here is an example. It uses the pomPostProcess setting to transform the generated POM right before it is written to disk. Essentially, we loop over all the XML nodes, looking for the element we care about and then rewrite it.
import scala.xml.{Node => XmlNode, NodeSeq => XmlNodeSeq, _}
import scala.xml.transform._
pomPostProcess := { node: XmlNode =>
val rule = new RewriteRule {
override def transform(n: XmlNode): XmlNodeSeq = n match {
case e: Elem if e != null && e.label == "packaging" =>
<packaging>pom</packaging>
case _ => n
}
}
new RuleTransformer(rule).transform(node).head
},
Maybe you could modify the result pom as described here: Modifying the generated POM
You can disable publishing the default artifacts of JAR, sources, and docs, then opt in explicitly to publishing the POM. sbt produces and publishes a POM only, with <packaging>pom</packaging>.
// This project has no sources, I want <packaging>pom</pom> with dependencies
lazy val bundle = project
.dependsOn(moduleA, moduleB)
.settings(
publishArtifact := false, // Disable jar, sources, docs
publishArtifact in makePom := true,
)
lazy val moduleA = project
lazy val moduleB = project
lazy val moduleC = project
Run sbt bundle/publishM2 to verify the POM in ~/.m2/repository.
I dare say this is almost intuitive, a rare moment of pleasant surprise with sbt 😅
I confirmed this with current sbt 1.3.9, and 1.0.1, the oldest launcher I happen to have installed on my machine.
The Artifacts page in the reference docs may be helpful, perhaps this trick should be added there.

How do I add a Nexus resolver after local repository, but before the default repositories?

We have an internal Nexus repository that we use to publish artifacts to and also to cache external dependencies (from Maven Central, Typesafe, etc.)
I want to add the repository as a resolver in my SBT build, under the following restrictions:
The settings need to be part of the build declaration (either .sbt or .scala, but not in the "global" sbt settings
If a dependency exists in the local repository, it should be taken from there. I don't want to have to access the network to get all the dependencies for every build.
If a dependency doesn't exist locally, sbt should first try to get it from the Nexus repository before trying the external repositories.
I saw several similar questions here, but didn't find any solution that does exactly this. Specifically, the code I currently have is:
externalResolvers ~= { rs => nexusResolver +: rs }
But when I show externalResolvers the Nexus repo appears before the local one.
So far, I've come up with the following solution:
externalResolvers ~= { rs =>
val grouped = rs.groupBy(_.isInstanceOf[FileRepository])
val fileRepos = grouped(true)
val remoteRepos = grouped(false)
fileRepos ++ (nexusResolver +: remoteRepos)
}
It works, but is kinda dirty... If anyone has a "cleaner" solution, I'd love to hear it.

How to stop xsbt from reloading webapp on resources change

We are using sbt with xsbt-web-plugin to develop our liftweb app. In our project build we have several subprojects and we use dependencies of a Project to share some stuff between all the subprojects.
object ProjectBuild extends Build {
//...
lazy val standalone = Project(
id = "standalone",
base = file("standalone"),
settings = Seq(...),
dependencies = Seq(core) // please notice this
)
lazy val core = Project(
id = "core",
base = file("core"),
settings = Seq(...)
}
// ...
}
To ease the development we use 'project standalone' '~;container:start; container:reload /' command automatically recompile changed files.
We decided to serve some common assets from shared core project as well. This works fine with lift. But what we faced when added our files to core/src/main/resources/toserve folder, is that any change to any javascript or css file causes application to restart jetty. This is annoying since such reload takes lots of resources.
So I started investigating on how to prevent this, even found someone mentioning watchSources sbt task that scans for changed files.
But adding this code as a watchSources modification (event that println prints all the files) does not prevent from reloading webapp each time I change assets located in core resources folder.
lazy val core = Project(
id = "core",
base = file("core"),
settings = Seq(
// ...
// here I added some tuning of watchSources
watchSources ~= { (ws: Seq[File]) => ws filterNot { path =>
println(path.getAbsolutePath)
path.getAbsolutePath.endsWith(".js")
} }
)
I also tried adding excludeFilter to unmanagedSorces, unmanagedResorces but with no luck.
I'm not an sbt expert and such modification of settings looks more like a magic for me (rather then a usual code). Also such tuning seem to be uncovered by documentation =(
Can anyone please help me to prevent sbt from reloading webapp on each asset file change?
Thanks a lot!
You're on the right track by using watchSources, but you'll also need to exclude the resources directory itself:
watchSources ~= { (ws: Seq[File]) =>
ws filterNot { path =>
path.getName.endsWith(".js") || path.getName == ("resources")
}
}
Can you switch from using "resources" folder to using "webapp" folder? That will also free you from restarts. Here's a demo project for Lift (that uses "webapp"):
https://github.com/lift/lift_26_sbt/
For example, the "basic" template:
https://github.com/lift/lift_26_sbt/tree/master/scala_211/lift_basic/src/main/webapp

Adding /etc/<application> to the classpath in sbt-native-packager for debian:package-bin

So I'm using the packageArchetype.java_server and setup my mappings so the files from "src/main/resources" go into my "/etc/" folder in the debian package. I'm using "sbt debian:package-bin" to create the package
The trouble is when I use "sbt run" it picks up the src/main/resources from the classpath. What's the right way to get the sbt-native-packager to give /etc/ as a resource classpath for my configuration and logging files?
plugins.sbt:
addSbtPlugin("com.typesafe.sbt" % "sbt-native-packager" % "0.7.0-M2")
build.sbt
...
packageArchetype.java_server
packageDescription := "Some Description"
packageSummary := "My App Daemon"
maintainer := "Me<me#example.org>"
mappings in Universal ++= Seq(
file("src/main/resources/application.conf") -> "conf/application.conf",
file("src/main/resources/logback.xml") -> "conf/logback.xml"
)
....
I took a slightly different approach. Since sbt-native-packager keeps those two files (application.conf and logback.xml) in my package distribution jar file, I really just wanted a way to overwrite (or merge) these files from /etc. I kept the two mappings above and just added the following:
src/main/templates/etc-default:
-Dmyapplication.config=/etc/${{app_name}}/application.conf
-Dlogback.configurationFile=/etc/${{app_name}}/logback.xml
Then within my code (using Typesafe Config Libraries):
lazy val baseConfig = ConfigFactory.load //defaults from src/resources
//For use in Debain packaging script. (see etc-default)
val systemConfig = Option(System.getProperty("myapplication.config")) match {
case Some(cfile) => ConfigFactory.parseFile(new File(cfile)).withFallback(baseConfig)
case None => baseConfig
}
And of course -Dlogback.configuration is a system propety used by Logback.

Defining plugin dependency between subprojects in SBT?

EDIT:
Since I put up the bounty, I thought I should restate the question
How can a SBT project P, with two sub-projects A and B, set up B to have a plugin dependency on A, which is a SBT plugin?
Giving P a plugin dependency on A does not work, since A depends on other things in P, which results in a circular dependency graph
It has to be a plugin dependency, for A is a plugin needed to run Bs test suite.
dependsOn doesn't work, because, well, it has to be a plugin dependency
I'd like to know either of
How to do this, or
Why this is impossible, and what the next best alternatives are.
EDIT: clarified that it's a plugin-dependency, since build-dependency is ambiguous
When you have a multi-project build configuration with "project P and two sub-projects A and B" it boils down to the following configuration:
build.sbt
lazy val A, B = project
As per design, "If a project is not defined for the root directory in the build, sbt creates a default one that aggregates all other projects in the build." It means that you will have an implicit root project, say P (but the name is arbitrary):
[plugin-project-and-another]> projects
[info] In file:/Users/jacek/sandbox/so/plugin-project-and-another/
[info] A
[info] B
[info] * plugin-project-and-another
That gives us the expected project structure. On to defining plugin dependency between B and A.
The only way to define a plugin in a SBT project is to use project directory that's the plugins project's build definition - "A plugin definition is a project in <main-project>/project/." It means that the only way to define a plugin dependency on the project A is to use the following:
project/plugins.sbt
addSbtPlugin("org.example" % "example-plugin" % "1.0")
lazy val plugins = project in file(".") dependsOn(file("../A"))
In this build configuration, the plugins project depends on another SBT project that happens to be our A that's in turn a plugin project.
A/build.sbt
// http://www.scala-sbt.org/release/docs/Extending/Plugins.html#example-plugin
sbtPlugin := true
name := "example-plugin"
organization := "org.example"
version := "1.0"
A/MyPlugin.scala
import sbt._
object MyPlugin extends Plugin
{
// configuration points, like the built in `version`, `libraryDependencies`, or `compile`
// by implementing Plugin, these are automatically imported in a user's `build.sbt`
val newTask = taskKey[Unit]("A new task.")
val newSetting = settingKey[String]("A new setting.")
// a group of settings ready to be added to a Project
// to automatically add them, do
val newSettings = Seq(
newSetting := "Hello from plugin",
newTask := println(newSetting.value)
)
// alternatively, by overriding `settings`, they could be automatically added to a Project
// override val settings = Seq(...)
}
The two files - build.sbt and MyPlugin.scala in the directory A - make up the plugin project.
The only missing piece is to define the plugin A's settings for the project B.
B/build.sbt
MyPlugin.newSettings
That's pretty much it what you can do in SBT. If you want to have multi-project build configuration and have a plugin dependency between (sub)projects, you don't have much choice other than what described above.
With that said, let's see if the plugin from the project A is accessible.
[plugin-project-and-another]> newTask
Hello from plugin
[success] Total time: 0 s, completed Feb 13, 2014 2:29:31 AM
[plugin-project-and-another]> B/newTask
Hello from plugin
[success] Total time: 0 s, completed Feb 13, 2014 2:29:36 AM
[plugin-project-and-another]> A/newTask
[error] No such setting/task
[error] A/newTask
[error] ^
As you may have noticed, newTask (that comes from the plugin from the project A) is available in the (default) root project and the project B, but not in A.
As Jacek said, it cannot be done as I would like, as a subproject cannot have a SBT plugin that the root project does not. On the other hand, this discussion on the mailing list contains several alternatives, and would no doubt be useful to anyone who comes across this question in the future.
EDIT: Well, in the end the alternatives mentioned (sbt scripted, etc) were hard and clunky to use. My final solution was to just have a separate project (not subproject) inside the repo that depends on the original project via it's ivy coordinates, and using bash to publishLocal the first project, going into the second project and running its tests
sbt publishLocal; cd test; sbt test; cd ..
I always thought the point of something like SBT was to avoid doing this kind of bash gymnastics, but desperate times call for desperate measures...
This answer may include the solution https://stackoverflow.com/a/12754868/3189923 .
From that link, in short, set exportJars := true and to obtain jar file paths for a (sub)project exportedProducts in Compile.
Leaving the facts about plugins by side, you have a parent project P with sub-projects A and B. And then you state that A depends on P. But P is a aggregate of A and B and hence depends on A. So you already have a circular dependency between A and P. This can never work.
You have to split P in two parts: The part where A depends on (let's call this part A') and the rest (let's call this P_rest). Then you throw away P and make a new project P_rest consisting of A', A and B. And A depends on A'.

Resources