diff --git a/.vsts-ci.yml b/.vsts-ci.yml
index 85311f6eac03..879a039caf90 100644
--- a/.vsts-ci.yml
+++ b/.vsts-ci.yml
@@ -16,101 +16,101 @@ jobs:
 ###########################################
 - job: Linux
 ###########################################
- variables:
-   COMPILER: gcc
- pool:
-   vmImage: 'ubuntu-latest'
- container: ubuntu1404
- strategy:
-   maxParallel: 6
-   matrix:
-     regular:
-       TASK: regular
-     sdist:
-       TASK: sdist
-       PYTHON_VERSION: 3.5
-     bdist:
-       TASK: bdist
-       PYTHON_VERSION: 3.6
-     inference:
-       TASK: if-else
-     mpi_source:
-       TASK: mpi
-       METHOD: source
-       PYTHON_VERSION: 2.7
-     gpu_source:
-       TASK: gpu
-       METHOD: source
-       PYTHON_VERSION: 3.6
-     r_package:
-       TASK: r-package
- steps:
- - script: |
-     echo "##vso[task.setvariable variable=HOME_DIRECTORY]$AGENT_HOMEDIRECTORY"
-     echo "##vso[task.setvariable variable=BUILD_DIRECTORY]$BUILD_SOURCESDIRECTORY"
-     echo "##vso[task.setvariable variable=OS_NAME]linux"
-     echo "##vso[task.setvariable variable=AZURE]true"
-     echo "##vso[task.setvariable variable=LGB_VER]$(head -n 1 VERSION.txt)"
-     echo "##vso[task.prependpath]$CONDA/bin"
-     AMDAPPSDK_PATH=$BUILD_SOURCESDIRECTORY/AMDAPPSDK
-     echo "##vso[task.setvariable variable=AMDAPPSDK_PATH]$AMDAPPSDK_PATH"
-     LD_LIBRARY_PATH=$AMDAPPSDK_PATH/lib/x86_64:$LD_LIBRARY_PATH
-     echo "##vso[task.setvariable variable=LD_LIBRARY_PATH]$LD_LIBRARY_PATH"
-     echo "##vso[task.setvariable variable=OPENCL_VENDOR_PATH]$AMDAPPSDK_PATH/etc/OpenCL/vendors"
-   displayName: 'Set variables'
- - bash: $(Build.SourcesDirectory)/.ci/setup.sh
-   displayName: Setup
- - bash: $(Build.SourcesDirectory)/.ci/test.sh
-   displayName: Test
- - task: PublishBuildArtifacts@1
-   condition: and(succeeded(), in(variables['TASK'], 'regular', 'sdist', 'bdist'), not(startsWith(variables['Build.SourceBranch'], 'refs/pull/')))
-   inputs:
-     pathtoPublish: '$(Build.ArtifactStagingDirectory)'
-     artifactName: PackageAssets
-     artifactType: container
+  variables:
+    COMPILER: gcc
+  pool:
+    vmImage: 'ubuntu-latest'
+  container: ubuntu1404
+  strategy:
+    maxParallel: 6
+    matrix:
+      regular:
+        TASK: regular
+      sdist:
+        TASK: sdist
+        PYTHON_VERSION: 3.5
+      bdist:
+        TASK: bdist
+        PYTHON_VERSION: 3.6
+      inference:
+        TASK: if-else
+      mpi_source:
+        TASK: mpi
+        METHOD: source
+        PYTHON_VERSION: 2.7
+      gpu_source:
+        TASK: gpu
+        METHOD: source
+        PYTHON_VERSION: 3.6
+      r_package:
+        TASK: r-package
+  steps:
+  - script: |
+      echo "##vso[task.setvariable variable=HOME_DIRECTORY]$AGENT_HOMEDIRECTORY"
+      echo "##vso[task.setvariable variable=BUILD_DIRECTORY]$BUILD_SOURCESDIRECTORY"
+      echo "##vso[task.setvariable variable=OS_NAME]linux"
+      echo "##vso[task.setvariable variable=AZURE]true"
+      echo "##vso[task.setvariable variable=LGB_VER]$(head -n 1 VERSION.txt)"
+      echo "##vso[task.prependpath]$CONDA/bin"
+      AMDAPPSDK_PATH=$BUILD_SOURCESDIRECTORY/AMDAPPSDK
+      echo "##vso[task.setvariable variable=AMDAPPSDK_PATH]$AMDAPPSDK_PATH"
+      LD_LIBRARY_PATH=$AMDAPPSDK_PATH/lib/x86_64:$LD_LIBRARY_PATH
+      echo "##vso[task.setvariable variable=LD_LIBRARY_PATH]$LD_LIBRARY_PATH"
+      echo "##vso[task.setvariable variable=OPENCL_VENDOR_PATH]$AMDAPPSDK_PATH/etc/OpenCL/vendors"
+    displayName: 'Set variables'
+  - bash: $(Build.SourcesDirectory)/.ci/setup.sh
+    displayName: Setup
+  - bash: $(Build.SourcesDirectory)/.ci/test.sh
+    displayName: Test
+  - task: PublishBuildArtifacts@1
+    condition: and(succeeded(), in(variables['TASK'], 'regular', 'sdist', 'bdist'), not(startsWith(variables['Build.SourceBranch'], 'refs/pull/')))
+    inputs:
+      pathtoPublish: '$(Build.ArtifactStagingDirectory)'
+      artifactName: PackageAssets
+      artifactType: container
 ###########################################
 - job: MacOS
 ###########################################
- variables:
-   COMPILER: clang
- pool:
-   vmImage: 'macOS-10.14'
- strategy:
-   maxParallel: 3
-   matrix:
-     regular:
-       TASK: regular
-       PYTHON_VERSION: 3.6
-     sdist:
-       TASK: sdist
-       PYTHON_VERSION: 3.5
-     bdist:
-       TASK: bdist
-     r_package:
-       TASK: r-package
- steps:
- - script: |
-     echo "##vso[task.setvariable variable=HOME_DIRECTORY]$AGENT_HOMEDIRECTORY"
-     echo "##vso[task.setvariable variable=BUILD_DIRECTORY]$BUILD_SOURCESDIRECTORY"
-     echo "##vso[task.setvariable variable=OS_NAME]macos"
-     echo "##vso[task.setvariable variable=AZURE]true"
-     echo "##vso[task.setvariable variable=LGB_VER]$(head -n 1 VERSION.txt)"
-     CONDA=$AGENT_HOMEDIRECTORY/miniconda
-     echo "##vso[task.setvariable variable=CONDA]$CONDA"
-     echo "##vso[task.prependpath]$CONDA/bin"
-     echo "##vso[task.setvariable variable=JAVA_HOME]$JAVA_HOME_8_X64"
-     echo "##vso[task.setvariable variable=R_MAC_VERSION]3.6.3"
-   displayName: 'Set variables'
- - bash: $(Build.SourcesDirectory)/.ci/setup.sh
-   displayName: Setup
- - bash: $(Build.SourcesDirectory)/.ci/test.sh
-   displayName: Test
- - task: PublishBuildArtifacts@1
-   condition: and(succeeded(), in(variables['TASK'], 'regular', 'sdist', 'bdist'), not(startsWith(variables['Build.SourceBranch'], 'refs/pull/')))
-   inputs:
-     pathtoPublish: '$(Build.ArtifactStagingDirectory)'
-     artifactName: PackageAssets
-     artifactType: container
+  variables:
+    COMPILER: clang
+  pool:
+    vmImage: 'macOS-10.14'
+  strategy:
+    maxParallel: 3
+    matrix:
+      regular:
+        TASK: regular
+        PYTHON_VERSION: 3.6
+      sdist:
+        TASK: sdist
+        PYTHON_VERSION: 3.5
+      bdist:
+        TASK: bdist
+      r_package:
+        TASK: r-package
+  steps:
+  - script: |
+      echo "##vso[task.setvariable variable=HOME_DIRECTORY]$AGENT_HOMEDIRECTORY"
+      echo "##vso[task.setvariable variable=BUILD_DIRECTORY]$BUILD_SOURCESDIRECTORY"
+      echo "##vso[task.setvariable variable=OS_NAME]macos"
+      echo "##vso[task.setvariable variable=AZURE]true"
+      echo "##vso[task.setvariable variable=LGB_VER]$(head -n 1 VERSION.txt)"
+      CONDA=$AGENT_HOMEDIRECTORY/miniconda
+      echo "##vso[task.setvariable variable=CONDA]$CONDA"
+      echo "##vso[task.prependpath]$CONDA/bin"
+      echo "##vso[task.setvariable variable=JAVA_HOME]$JAVA_HOME_8_X64"
+      echo "##vso[task.setvariable variable=R_MAC_VERSION]3.6.3"
+    displayName: 'Set variables'
+  - bash: $(Build.SourcesDirectory)/.ci/setup.sh
+    displayName: Setup
+  - bash: $(Build.SourcesDirectory)/.ci/test.sh
+    displayName: Test
+  - task: PublishBuildArtifacts@1
+    condition: and(succeeded(), in(variables['TASK'], 'regular', 'sdist', 'bdist'), not(startsWith(variables['Build.SourceBranch'], 'refs/pull/')))
+    inputs:
+      pathtoPublish: '$(Build.ArtifactStagingDirectory)'
+      artifactName: PackageAssets
+      artifactType: container
 ###########################################
 - job: Windows
 ###########################################
@@ -150,47 +150,47 @@ jobs:
 ###########################################
 - job: Package
 ###########################################
- dependsOn:
- - Linux
- - MacOS
- - Windows
- condition: and(succeeded(), not(startsWith(variables['Build.SourceBranch'], 'refs/pull/')))
- pool:
-   vmImage: 'vs2017-win2016'
- steps:
- # Download all agent packages from all previous phases
- - task: DownloadBuildArtifacts@0
-   displayName: Download package assets
-   inputs:
-     artifactName: PackageAssets
-     downloadPath: $(Build.SourcesDirectory)/binaries
- - script: |
-     python %BUILD_SOURCESDIRECTORY%/.nuget/create_nuget.py %BUILD_SOURCESDIRECTORY%/binaries/PackageAssets
-   displayName: 'Create NuGet configuration files'
- - task: NuGetCommand@2
-   inputs:
-     command: pack
-     packagesToPack: '$(Build.SourcesDirectory)/.nuget/*.nuspec'
-     packDestination: '$(Build.ArtifactStagingDirectory)'
- - task: PublishBuildArtifacts@1
-   inputs:
-     pathtoPublish: '$(Build.ArtifactStagingDirectory)'
-     artifactName: NuGet
-     artifactType: container
- - task: GitHubRelease@0
-   displayName: 'Create GitHub Release'
-   condition: and(succeeded(), startsWith(variables['Build.SourceBranch'], 'refs/tags/v'))
-   inputs:
-     gitHubConnection: guolinke
-     repositoryName: '$(Build.Repository.Name)'
-     action: 'create'
-     target: '$(Build.SourceVersion)'
-     tagSource: 'auto'
-     title: '$(Build.SourceBranchName)'
-     assets: |
-       $(Build.SourcesDirectory)/binaries/PackageAssets/*
-       $(Build.ArtifactStagingDirectory)/*.nupkg
-     assetUploadMode: 'delete'
-     isDraft: true
-     isPreRelease: false
-     addChangeLog: false
+  dependsOn:
+  - Linux
+  - MacOS
+  - Windows
+  condition: and(succeeded(), not(startsWith(variables['Build.SourceBranch'], 'refs/pull/')))
+  pool:
+    vmImage: 'vs2017-win2016'
+  steps:
+  # Download all agent packages from all previous phases
+  - task: DownloadBuildArtifacts@0
+    displayName: Download package assets
+    inputs:
+      artifactName: PackageAssets
+      downloadPath: $(Build.SourcesDirectory)/binaries
+  - script: |
+      python %BUILD_SOURCESDIRECTORY%/.nuget/create_nuget.py %BUILD_SOURCESDIRECTORY%/binaries/PackageAssets
+    displayName: 'Create NuGet configuration files'
+  - task: NuGetCommand@2
+    inputs:
+      command: pack
+      packagesToPack: '$(Build.SourcesDirectory)/.nuget/*.nuspec'
+      packDestination: '$(Build.ArtifactStagingDirectory)'
+  - task: PublishBuildArtifacts@1
+    inputs:
+      pathtoPublish: '$(Build.ArtifactStagingDirectory)'
+      artifactName: NuGet
+      artifactType: container
+  - task: GitHubRelease@0
+    displayName: 'Create GitHub Release'
+    condition: and(succeeded(), startsWith(variables['Build.SourceBranch'], 'refs/tags/v'))
+    inputs:
+      gitHubConnection: guolinke
+      repositoryName: '$(Build.Repository.Name)'
+      action: 'create'
+      target: '$(Build.SourceVersion)'
+      tagSource: 'auto'
+      title: '$(Build.SourceBranchName)'
+      assets: |
+        $(Build.SourcesDirectory)/binaries/PackageAssets/*
+        $(Build.ArtifactStagingDirectory)/*.nupkg
+      assetUploadMode: 'delete'
+      isDraft: true
+      isPreRelease: false
+      addChangeLog: false