Use coursier support for ~/.m2/settings.xml for proxy auth

build.sc

@@ -702,6 +702,7 @@ trait Cli extends SbtModule with ProtoBuildModule with CliLaunchers
 
   def ivyDeps = super.ivyDeps() ++ Agg(
     Deps.coursierLauncher,
+    Deps.coursierProxySetup,
     Deps.coursierPublish,
     Deps.jimfs, // scalaJsEnvNodeJs pulls jimfs:1.1, whose class path seems borked (bin compat issue with the guava version it depends on)
     Deps.jniUtils,

modules/cli/src/main/scala/scala/cli/ScalaCli.scala

@@ -1,6 +1,6 @@
 package scala.cli
 
-import coursier.cache.CacheUrl
+import coursier.proxy.SetupProxy
 import sun.misc.{Signal, SignalHandler}
 
 import java.io.{ByteArrayOutputStream, File, PrintStream}
@@ -153,7 +153,7 @@ object ScalaCli {
 
     (new BouncycastleSignerMaker).maybeInit()
 
-    CacheUrl.setupProxyAuth()
+    SetupProxy.setup()
 
     // Getting killed by SIGPIPE quite often when on musl (in the "static" native
     // image), but also sometimes on glibc, or even on macOS, when we use domain

modules/integration/src/test/scala/scala/cli/integration/RunTestDefinitions.scala

@@ -1585,7 +1585,8 @@ abstract class RunTestDefinitions(val scalaVersionOpt: Option[String])
           s"-D$scheme.proxyHost=$host",
           s"-D$scheme.proxyPort=$port",
           s"-D$scheme.proxyUser=$user",
-          s"-D$scheme.proxyPassword=$password"
+          s"-D$scheme.proxyPassword=$password",
+          s"-D$scheme.proxyProtocol=http"
         )
       }
     val proxyArgs      = authProperties("localhost", 9083, "jack", "insecure")

project/deps.sc

@@ -56,7 +56,7 @@ object InternalDeps {
 object Deps {
   object Versions {
     // jni-utils version may need to be sync-ed when bumping the coursier version
-    def coursier      = "2.1.0-M6"
+    def coursier      = "2.1.0-M6-26-gcec901e9a"
     def coursierCli   = "2.1.0-M5-18-gfebf9838c"
     def jsoniterScala = "2.13.26"
     def scalaMeta     = "4.5.8"
@@ -72,10 +72,11 @@ object Deps {
   def caseApp          = ivy"com.github.alexarchambault:case-app_2.13:2.1.0-M13"
   def collectionCompat = ivy"org.scala-lang.modules::scala-collection-compat:2.7.0"
   // Force using of 2.13 - is there a better way?
-  def coursier         = ivy"io.get-coursier:coursier_2.13:${Versions.coursier}"
-  def coursierJvm      = ivy"io.get-coursier:coursier-jvm_2.13:${Versions.coursier}"
-  def coursierLauncher = ivy"io.get-coursier:coursier-launcher_2.13:${Versions.coursier}"
-  def coursierPublish  = ivy"io.get-coursier.publish:publish_2.13:0.1.2"
+  def coursier           = ivy"io.get-coursier:coursier_2.13:${Versions.coursier}"
+  def coursierJvm        = ivy"io.get-coursier:coursier-jvm_2.13:${Versions.coursier}"
+  def coursierLauncher   = ivy"io.get-coursier:coursier-launcher_2.13:${Versions.coursier}"
+  def coursierProxySetup = ivy"io.get-coursier:coursier-proxy-setup:${Versions.coursier}"
+  def coursierPublish    = ivy"io.get-coursier.publish:publish_2.13:0.1.2"
   // TODO - update to working version
   def dependency   = ivy"io.get-coursier::dependency:0.2.2"
   def dockerClient = ivy"com.spotify:docker-client:8.16.0"

website/docs/reference/proxy-authentication.md

@@ -0,0 +1,67 @@
+---
+title: Proxy authentication
+sidebar_position: 9
+---
+
+Scala CLI can download dependencies via HTTP proxies. Proxies can be setup in several ways:
+- via the Maven configuration file (recommended for now)
+- via command-line options
+- via Scala CLI or coursier configuration files (soon)
+
+## Maven configuration file
+
+This file lives at `~/.m2/settings.xml`
+
+Example configuration file, without authentication:
+```xml
+<settings>
+  <proxies>
+    <proxy>
+      <id>test-proxy</id>
+      <protocol>http</protocol>
+      <host>proxy.corp.com</host>
+      <port>8080</port>
+    </proxy>
+  </proxies>
+</settings>
+```
+
+Example configuration file, with authentication:
+```xml
+<settings>
+  <proxies>
+    <proxy>
+      <id>test-proxy</id>
+      <protocol>http</protocol>
+      <host>proxy.corp.com</host>
+      <port>8080</port>
+      <username>alex</username>
+      <password>1234</password>
+    </proxy>
+  </proxies>
+</settings>
+```
+
+The value in `<protocol>…</protocol>` is assumed to be the protocol of the proxy itself
+(can be either `http` or `https`, `https` is assumed by default not to inadvertently leak
+proxy credentials).
+
+Such a proxy is used for both http and https by Scala CLI.
+
+The [coursier](https://github.com/coursier/coursier) command-line and library also pick those credentials, since version `2.1.0-M6-26-gcec901e9a` (2022/05/31).
+
+## Command-line options
+
+Example
+```
+$ scala-cli \
+    -Dhttp.proxyProtocol=http -Dhttp.proxyHost=proxy.corp.com -Dhttp.proxyPort=8080 \
+    -Dhttp.proxyUsername=alex -Dhttp.proxyPassword=1234 \
+    -Dhttps.proxyProtocol=http -Dhttps.proxyHost=proxy.corp.com -Dhttps.proxyPort=8080 \
+    -Dhttps.proxyUsername=alex -Dhttps.proxyPassword=1234 \
+    <(echo 'println("Hello from Scala CLI")')
+```
+
+## Coursier or Scala CLI configuration files
+
+Support to be added soon