update:CI: skip the build steps if the change is only for documentation

2 files changed, 54 insertions, 0 deletions

diff --git a/.circleci/config.yml b/.circleci/config.yml
index bb542a94d..e9af55c9e 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -18,6 +18,7 @@ jobs:
     <<: *defaults
     steps:
       - checkout
+      - run: if scripts/check_need_build.sh; then circleci step halt; fi
       - run:
           name: Id
           command: cat /etc/*release
@@ -39,6 +40,7 @@ jobs:
     <<: *defaults
     steps:
       - checkout
+      - run: if scripts/check_need_build.sh; then circleci step halt; fi
       - run:
           name: Install doxygen and other essentials
           command: apt-get update && apt-get -y install doxygen ca-certificates git rsync
@@ -54,6 +56,7 @@ jobs:
     machine: true
     steps:
       - checkout
+      - run: if scripts/check_need_build.sh; then circleci step halt; fi
       - run:
           name: install docker
           command: circleci-install docker
@@ -75,6 +78,7 @@ jobs:
       GRADLE_OPTS: '-Dorg.gradle.jvmargs="-Xmx2048m -XX:+HeapDumpOnOutOfMemoryError"'
     steps:
       - checkout
+      - run: if scripts/check_need_build.sh; then circleci step halt; fi
       - run:
           name: Id
           command: cat /etc/*release
@@ -131,6 +135,7 @@ jobs:
       - image: ubuntu:14.04
     steps:
       - checkout
+      - run: if scripts/check_need_build.sh; then circleci step halt; fi
       - run:
           name: Prepare the Windows build environment
           command: |
@@ -154,6 +159,7 @@ jobs:
       - image: navit/dockerfiles:wince
     steps:
       - checkout
+      - run: if scripts/check_need_build.sh; then circleci step halt; fi
       - run:
           name: Prepare the WinCE build environment
           command: |
@@ -173,6 +179,7 @@ jobs:
       - image: navit/tomtom-ng
     steps:
       - checkout
+      - run: if scripts/check_need_build.sh; then circleci step halt; fi
       - run:
           name: Setup common requirements
           command: |
@@ -193,6 +200,7 @@ jobs:
       - image: navit/tomtom-ng
     steps:
       - checkout
+      - run: if scripts/check_need_build.sh; then circleci step halt; fi
       - run:
           name: Setup common requirements
           command: |
diff --git a/scripts/check_need_build.sh b/scripts/check_need_build.sh
new file mode 100755
index 000000000..29937764f
--- /dev/null
+++ b/scripts/check_need_build.sh
@@ -0,0 +1,46 @@
+#!/bin/bash -e
+# ################################################################################################################### #
+# This file exits 1 if there are files of interest that should trigger a build and exits normally otherwise.          #
+# The idea is also to build if the exit code is different from 0 as it means we cannot get a filtered list properly.  #
+# ################################################################################################################### #
+
+# @brief: constructs the list of files that differ from the trunk branch.
+#         Note that if you are on the trunk or master branch it will return the files modified by the last commit.
+# @param: a variable you want to use to get the resulting value
+# @return: nothing (the input variable is modified according to the brief description)
+list_files_git_diff(){
+    local -n files=$1
+    files=$(git diff --name-only refs/remotes/origin/trunk)
+
+    # If there is no diff that might just mean that you are on the trunk or master branch
+    # so you just want to check the last commit. This way we still have that check more
+    # or less working when pushing directly to trunk or when merging in master.
+    if [[ -z "$files" ]]; then
+        files=$(git diff --name-only HEAD^)
+    fi
+}
+
+# @brief: get the list of files that have differed from trunk (by calling list_files_git_diff for the full list)
+#         and filters out those don't match the pattern we use to exclude files that should not trigger a build.
+# @param: a variable you want to use to get the resulting value
+# @return: nothing (the input variable is modified according to the brief description)
+filtered_files_git_diff(){
+    local -n _ret=$1
+    declare -a filters=('^docs/.*', '.*\.md$', '.*\.rst$')
+    declare -a file_list=()
+    list_files_git_diff file_list
+    for f in ${file_list[@]}; do
+        for filter in "${filters[@]}" ; do
+            if [[ "$f" =~ $filter ]]; then
+                # This removes the element from the element matching the filter
+                file_list=(${file_list[@]/$f})
+                break
+            fi
+        done
+    done
+    _ret=$file_list
+}
+
+filtered_files_git_diff filtered_out_modified_files
+# exits with a 0 if the list is empty
+[[ -z "${filtered_out_modified_files}" ]]