How to enable .ivy2 caching for sbt when using a gitlab ci runner between builds

Question

When using gitlab ci runner and sbt, I want to avoid downloading all the sbt jar files each time there is a build. Is there any way I can cache this? Here's my .gitlab-ci.yml file which does not cache successfully the .ivy2 files.

image: openjdk:8-jre-alpine

services:
- docker:dind

variables:
  SBT_VERSION: "0.13.13"
  SBT_HOME: "/usr/local/sbt"
  SBT_JAR: "http://dl.bintray.com/sbt/native-    packages/sbt/${SBT_VERSION}/sbt-${SBT_VERSION}.tgz"

cache:
  paths:
    - ~/.ivy2

stages:
  - setup

setup:
  stage: setup
  script:
  - export PATH="${SBT_HOME}/bin:$PATH"
  - apk --update add bash wget curl tar git
  - wget ${SBT_JAR}
  - mkdir /usr/local/sbt
  - tar -xf sbt-${SBT_VERSION}.tgz -C /usr/local/sbt --strip-components=1
  - echo -ne "- with sbt sbt-${SBT_VERSION}\n" >> /root/.built
  - rm sbt-${SBT_VERSION}.tgz
  - echo "$PATH"
  - cat /root/.built
  - ls -als /usr/local/sbt
  - sbt sbt-version
  - ls -als ~/.ivy2

Answer 1

Assuming you are using a docker runner, then you need to update the config.toml file and make /root/.ivy2 persistent with a volume

here is mine:

concurrent = 1
check_interval = 0

[[runners]]
  name = xxx
  url = yyy
  token = zzz
  executor = "docker"
  [runners.docker]
    tls_verify = false
    image = "ruby:2.1"
    privileged = false
    disable_cache = false
    volumes = ["/cache", "/srv/home:/root/" ]
  [runners.cache]