From 00c754788f0e2b860c0c0c30d62a6debebefe4c2 Mon Sep 17 00:00:00 2001
From: Johannes Schnatterer <johannes.schnatterer@cloudogu.com>
Date: Thu, 25 Jun 2020 17:25:54 +0200
Subject: [PATCH] Allow for calling installDockerClient() without args.

---
 README.md                                           |  4 ++--
 src/com/cloudogu/ces/cesbuildlib/Docker.groovy      |  5 ++++-
 test/com/cloudogu/ces/cesbuildlib/DockerTest.groovy | 11 +++++++++++
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index b4308e07..be10b0ab 100644
--- a/README.md
+++ b/README.md
@@ -624,11 +624,11 @@ Example from Jenkinsfile:
    
    This is also used by [MavenInDocker](src/com/cloudogu/ces/cesbuildlib/MavenInDocker.groovy)
    
-* `installDockerClient(String version)`: Installs the docker client with the specified version inside the container.  
+* `installDockerClient(String version)`: Installs the docker client with the specified version inside the container.
+   If no version parameter is passed, the lib tries to query the server version by calling `docker version`.  
    This can be called in addition to mountDockerSocket(), when the "docker" CLI is required on the PATH.  
    
    For available versions see [here](https://download.docker.com/linux/static/stable/x86_64/).
-   For an exampl see [here](https://github.com/cloudogu/continuous-delivery-docs-example) 
 
 Examples:
 
diff --git a/src/com/cloudogu/ces/cesbuildlib/Docker.groovy b/src/com/cloudogu/ces/cesbuildlib/Docker.groovy
index 80f46471..d24399b2 100644
--- a/src/com/cloudogu/ces/cesbuildlib/Docker.groovy
+++ b/src/com/cloudogu/ces/cesbuildlib/Docker.groovy
@@ -282,7 +282,10 @@ class Docker implements Serializable {
          *
          *  For available versions see here: https://download.docker.com/linux/static/stable/x86_64/
          */
-        Image installDockerClient(String version) {
+        Image installDockerClient(String version = '') {
+            if (!version) {
+                version = sh.returnStdOut "docker version --format '{{.Server.Version}}'"
+            }
             this.dockerClientVersionToInstall = version
             return this
         }
diff --git a/test/com/cloudogu/ces/cesbuildlib/DockerTest.groovy b/test/com/cloudogu/ces/cesbuildlib/DockerTest.groovy
index a820c53e..9d3cc2cf 100644
--- a/test/com/cloudogu/ces/cesbuildlib/DockerTest.groovy
+++ b/test/com/cloudogu/ces/cesbuildlib/DockerTest.groovy
@@ -10,6 +10,7 @@ class DockerTest {
     def expectedImage = 'google/cloud-sdk:164.0.0'
     def expectedHome = '/home/jenkins'
     def actualUser = 'jenkins'
+    def actualDockerServerVersion = '19.03.8'
     def actualPasswd = "$actualUser:x:1000:1000:Jenkins,,,:/home/jenkins:/bin/bash"
     def actualDockerGroupId = "999"
     def actualDockerGroup = "docker:x:$actualDockerGroupId:jenkins"
@@ -383,6 +384,15 @@ class DockerTest {
             assert actualShArgs[0].contains("${it}.tgz")
         })
     }
+
+    @Test
+    void "install docker clients for current server version"() {
+        Docker docker = createWithImage(mockedImageMethodInside())
+        docker.image(expectedImage)
+                .installDockerClient()
+                .inside { return 'expectedClosure' }
+        assert actualShArgs[0].contains("${actualDockerServerVersion}.tgz")
+    }
     
     private Docker create(Map<String, Closure> mockedMethod) {
         Map<String, Map<String, Closure>> mockedScript = [
@@ -418,6 +428,7 @@ class DockerTest {
                     if (script == 'cat /etc/group | grep docker') return actualDockerGroup
                     if (script.contains(actualDockerGroup)) return actualDockerGroupId
                     if (script.contains('cat /etc/passwd | grep')) return actualPasswd
+                    if (script.contains('docker version --format \'{{.Server.Version}}\'')) return "  ${actualDockerServerVersion}  "    
                     else fail("Unexpected sh call. Script: " + script)
                 },
                 pwd: { return expectedHome },