Reduce go binary size by updating to go 1.15 (#1968)

* Update go to 1.15 to reduce binary size

Go made improvements to reduce binary size, cf https://golang.org/doc/go1.15

> Go 1.15 reduces typical binary sizes by around 5% compared to Go 1.14 by eliminating certain types of GC metadata and more aggressively eliminating unused type metadata.

In my test, this equates to about 3 mb diff between Go 1.13 and Go 1.15:

-rwxr-xr-x 1 root root 36M Aug 31 14:43 piper-go-113
-rwxr-xr-x 1 root root 33M Aug 31 14:44 piper-go-115

* Go Generate

* go mod tidy

Co-authored-by: Stephan Aßmus <stephan.assmus@sap.com>
Co-authored-by: Oliver Nocon <33484802+OliverNocon@users.noreply.github.com>

.github/workflows/documentation.yaml

@@ -21,7 +21,7 @@ jobs:
 
     - uses: actions/setup-go@v1
       with:
-        go-version: '1.13.x'
+        go-version: '1.15.x'
 
     - name: Install Groovy
       run: sudo apt-get update && sudo apt-get install groovy -y

.github/workflows/integration-tests-pr.yaml

@@ -76,7 +76,7 @@ jobs:
           curl --location --request POST 'https://api.github.com/repos/SAP/jenkins-library/statuses/${{ steps.commitId.outputs.commitId }}' -H 'Content-Type: application/json' --data '{"state": "pending", "context": "Go / integration-tests", "target_url": "https://github.com/SAP/jenkins-library/actions/runs/${{ github.run_id }}"}' -H 'Authorization: token ${{secrets.INTEGRATION_TEST_VOTING_TOKEN}}'
       - uses: actions/setup-go@v1
         with:
-          go-version: '1.13.x'
+          go-version: '1.15.x'
       - name: build
         env:
           CGO_ENABLED: 0

.github/workflows/integration-tests.yaml

@@ -55,7 +55,7 @@ jobs:
           curl --location --request POST 'https://api.github.com/repos/SAP/jenkins-library/statuses/${{ steps.commitId.outputs.commitId }}' -H 'Content-Type: application/json' --data '{"state": "pending", "context": "Go / integration-tests", "target_url": "https://github.com/SAP/jenkins-library/actions/runs/${{ github.run_id }}"}' -H 'Authorization: token ${{secrets.INTEGRATION_TEST_VOTING_TOKEN}}'
       - uses: actions/setup-go@v1
         with:
-          go-version: '1.13.x'
+          go-version: '1.15.x'
       - name: build
         env:
           CGO_ENABLED: 0

.github/workflows/update-go-dependencies.yaml

@@ -15,7 +15,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-go@v1
         with:
-          go-version: '1.13.x'
+          go-version: '1.15.x'
       - name: Perform update
         run: |
           git checkout -B gh-action-update-golang-dependencies

.github/workflows/upload-go-master.yml

@@ -12,7 +12,7 @@ jobs:
       - uses: actions/checkout@v1
       - uses: actions/setup-go@v1
         with:
-          go-version: '1.13.x'
+          go-version: '1.15.x'
       - env:
           CGO_ENABLED: 0
         run: |

.github/workflows/verify-go.yml

@@ -14,7 +14,7 @@ jobs:
     steps:
     - uses: actions/setup-go@v1
       with:
-        go-version: '1.13.x'
+        go-version: '1.15.x'
     - name: Cache Golang Packages
       uses: actions/cache@v1
       with:
@@ -38,7 +38,7 @@ jobs:
     steps:
     - uses: actions/setup-go@v1
       with:
-        go-version: '1.13.x'
+        go-version: '1.15.x'
     - name: Cache Golang Packages
       uses: actions/cache@v1
       with:
@@ -58,7 +58,7 @@ jobs:
     steps:
     - uses: actions/setup-go@v1
       with:
-        go-version: '1.13.x'
+        go-version: '1.15.x'
     - name: Cache Golang Packages
       uses: actions/cache@v1
       with:
@@ -78,7 +78,7 @@ jobs:
     steps:
     - uses: actions/setup-go@v1
       with:
-        go-version: '1.13.x'
+        go-version: '1.15.x'
     - name: Cache Golang Packages
       uses: actions/cache@v1
       with:

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.13 AS build-env
+FROM golang:1.15 AS build-env
 COPY . /build
 WORKDIR /build
 

go.mod

@@ -1,6 +1,6 @@
 module github.com/SAP/jenkins-library
 
-go 1.13
+go 1.15
 
 require (
 	github.com/360EntSecGroup-Skylar/excelize/v2 v2.3.0

src/com/sap/piper/PiperGoUtils.groovy

@@ -25,7 +25,7 @@ class PiperGoUtils implements Serializable {
 
         if (steps.env.REPOSITORY_UNDER_TEST && steps.env.LIBRARY_VERSION_UNDER_TEST) {
             steps.echo("Running in a consumer test, building unit-under-test binary for verification.")
-            steps.dockerExecute(script: steps, dockerImage: 'golang:1.13', dockerOptions: '-u 0', dockerEnvVars: [
+            steps.dockerExecute(script: steps, dockerImage: 'golang:1.15', dockerOptions: '-u 0', dockerEnvVars: [
                 REPOSITORY_UNDER_TEST: steps.env.REPOSITORY_UNDER_TEST,
                 LIBRARY_VERSION_UNDER_TEST: steps.env.LIBRARY_VERSION_UNDER_TEST
             ]) {