Support curl in addition to wget for gsutil

src/test/groovy/GsutilStepTests.groovy

@@ -95,11 +95,22 @@ class GsutilStepTests extends ApmBasePipelineTest {
   }
 
   @Test
-  void test_without_gh_installed_by_default_no_wget() throws Exception {
+  void test_without_gh_installed_by_default_no_wget_no_curl() throws Exception {
     helper.registerAllowedMethod('isInstalled', [Map.class], { return false })
     script.call(command: 'cp', credentialsId: 'foo')
     printCallStack()
     assertFalse(assertMethodCallContainsPattern('sh', 'wget -q -O'))
+    assertFalse(assertMethodCallContainsPattern('sh', 'curl'))
+    assertJobStatusSuccess()
+  }
+
+  @Test
+  void test_without_gh_installed_by_default_no_wget() throws Exception {
+    helper.registerAllowedMethod('isInstalled', [Map.class], { m -> return !(m.tool.equals('wget') || m.tool.equals('gsutil'))})
+    script.call(command: 'cp', credentialsId: 'foo')
+    printCallStack()
+    assertFalse(assertMethodCallContainsPattern('sh', 'wget -q -O gsutil.tar.gz'))
+    assertTrue(assertMethodCallContainsPattern('sh', 'curl -sSLo gsutil.tar.gz --retry 3 --retry-delay 2 --max-time 10'))
     assertJobStatusSuccess()
   }
 

vars/gsutil.groovy

@@ -46,16 +46,33 @@ def call(Map args = [:]) {
 def downloadInstaller(where) {
   def url = googleCloudSdkURL()
   def tarball = "gsutil.${isUnix() ? 'tar.gz' : 'zip'}"
+
+  dir(where) {
+    if (!downloadWithWget(tarball, url)) {
+      downloadWithCurl(tarball, url)
+    }
+    uncompress(tarball)
+  }
+}
+
+def downloadWithWget(tarball, url) {
   if(isInstalled(tool: 'wget', flag: '--version')) {
-    dir(where) {
-      retryWithSleep(retries: 3, seconds: 5, backoff: true) {
-        cmd(label: 'download gsutil', script: "wget -q -O ${tarball} ${url}")
-        uncompress(tarball)
-      }
+    retryWithSleep(retries: 3, seconds: 5, backoff: true) {
+      cmd(label: 'download gsutil', script: "wget -q -O ${tarball} ${url}")
     }
+    return true
   } else {
     log(level: 'WARN', text: 'gsutil: wget is not available. gsutil will not be installed then.')
   }
+  return false
+}
+
+def downloadWithCurl(tarball, url) {
+  if(isInstalled(tool: 'curl', flag: '--version')) {
+    cmd(label: 'download gsutil', script: "curl -sSLo ${tarball} --retry 3 --retry-delay 2 --max-time 10 ${url}")
+  } else {
+    log(level: 'WARN', text: 'gsutil: curl is not available. gsutil will not be installed then.')
+  }
 }
 
 def googleCloudSdkURL() {