Merge bitcoin#17635: ci: Add CentOS 7 build

711e044 ci: Remove trusty build (Hennadii Stepanov)
7f3ae22 ci: Add CentOS 7 build (Hennadii Stepanov)

Pull request description:

  Arguably, CentOS is the most conservative distro of all the popular ones. Thus, it could be a good way to check the Bitcoin Core compatibility with aged dependencies.

  Currently, CentOS 7 has:
  - Berkeley DB == 4.8.30
  - Boost == 1.53.0
  - GCC == 4.8.5
  - libevent == 2.0.21 < minimum required [2.0.22](https://github.com/bitcoin/bitcoin/blob/master/doc/dependencies.md), but tests passed
  - MiniUPnPc == 2.0
  - Python == 3.6.8
  - qrencode == 3.4.1
  - Qt == 5.9.7
  - ZeroMQ == 4.1.4

  ~Please note that this PR is based on the bugfix bitcoin#17634.~

  Also trusty build has been removed for the following reasons:
  - bitcoin#17628 (comment):
  > Maybe it'd make sense to replace Ubuntu Trusty with Centos 7 as the "check ancient backward compatibililty" Travis run. It's supported until 2024, apparently.

  - bitcoin#17635 (comment):
  > Our travis is currently running at its limit and this doesn't seem like it is adding a lot new coverage compared to the other builds.

  Close bitcoin#17628

ACKs for top commit:
  MarcoFalke:
    ACK 711e044 🚠

Tree-SHA512: 614ec8394943f482a5867067f7119bffd052924a51e32ffda9a08e10c392c4a955a3539e2f8907cb65bfd9347dadf0ba62f6d1530bbc49927c347360a5a7f73c

.travis.yml

@@ -105,14 +105,14 @@ jobs:
         FILE_ENV="./ci/test/00_setup_env_i686.sh"
 
     - stage: test
-      name: 'x86_64 Linux  [GOAL: install]  [bionic]  [uses qt5 dev package instead of depends Qt to speed up build and avoid timeout] [unsigned char]'
+      name: 'x86_64 Linux  [GOAL: install]  [CentOS 7]  [no depends, only system libs]'
       env: >-
-        FILE_ENV="./ci/test/00_setup_env_native_qt5.sh"
+        FILE_ENV="./ci/test/00_setup_env_native_centos.sh"
 
     - stage: test
-      name: 'x86_64 Linux  [GOAL: install]  [trusty]  [no functional tests, no depends, only system libs]'
+      name: 'x86_64 Linux  [GOAL: install]  [bionic]  [uses qt5 dev package instead of depends Qt to speed up build and avoid timeout] [unsigned char]'
       env: >-
-        FILE_ENV="./ci/test/00_setup_env_native_trusty.sh"
+        FILE_ENV="./ci/test/00_setup_env_native_qt5.sh"
 
     - stage: test
       name: 'x86_64 Linux  [GOAL: install]  [xenial]  [no depends, only system libs, sanitizers: thread (TSan), no wallet]'

ci/test/00_setup_env_native_centos.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) 2019 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+export LC_ALL=C.UTF-8
+
+export DOCKER_NAME_TAG=centos:7
+export DOCKER_PACKAGES="gcc-c++ libtool make git python3 python36-zmq"
+export PACKAGES="boost-devel libevent-devel libdb4-devel libdb4-cxx-devel miniupnpc-devel zeromq-devel qt5-qtbase-devel qt5-qttools-devel qrencode-devel"
+export NO_DEPENDS=1
+export GOAL="install"
+export BITCOIN_CONFIG="--enable-reduce-exports"

ci/test/04_install.sh

@@ -6,6 +6,10 @@
 
 export LC_ALL=C.UTF-8
 
+if [[ $DOCKER_NAME_TAG == centos* ]]; then
+  export LC_ALL=en_US.utf8
+fi
+
 if [ "$TRAVIS_OS_NAME" == "osx" ]; then
   set +o errexit
   pushd /usr/local/Homebrew || exit 1
@@ -82,7 +86,10 @@ if [ -n "$DPKG_ADD_ARCH" ]; then
   DOCKER_EXEC dpkg --add-architecture "$DPKG_ADD_ARCH"
 fi
 
-if [ "$TRAVIS_OS_NAME" != "osx" ]; then
+if [[ $DOCKER_NAME_TAG == centos* ]]; then
+  ${CI_RETRY_EXE} DOCKER_EXEC yum -y install epel-release
+  ${CI_RETRY_EXE} DOCKER_EXEC yum -y install $DOCKER_PACKAGES $PACKAGES
+elif [ "$TRAVIS_OS_NAME" != "osx" ]; then
   ${CI_RETRY_EXE} DOCKER_EXEC apt-get update
   ${CI_RETRY_EXE} DOCKER_EXEC apt-get install --no-install-recommends --no-upgrade -y $PACKAGES $DOCKER_PACKAGES
 fi