WIP: Use find_package for nlohmann_json

INSTALL.md

@@ -128,6 +128,7 @@ cc_binary(
 | libcurl | 7.47.0  | HTTP client library for the Google Cloud Storage client |
 | crc32c  | 1.0.6 | Hardware-accelerated CRC32C implementation |
 | OpenSSL | 1.0.2 | Crypto functions for Google Cloud Storage authentication |
+| nljson  | 3.6.1 | JSON for Modern C++ |
 
 Note that these libraries may also depend on other libraries. The following
 instructions include steps to install these indirect dependencies too.
@@ -165,7 +166,7 @@ tools to compile the dependencies:
 
 ```bash
 sudo dnf makecache && \
-sudo dnf install -y grpc-devel grpc-plugins \
+sudo dnf install -y grpc-devel grpc-plugins json-devel \
         libcurl-devel protobuf-compiler tar wget zlib-devel
 ```
 
@@ -221,7 +222,8 @@ Platform proto files.
 
 ```bash
 sudo zypper refresh && \
-sudo zypper install -y grpc-devel gzip libcurl-devel pkg-config tar wget
+sudo zypper install -y grpc-devel gzip libcurl-devel nlohmann_json \
+        pkg-config tar wget
 ```
 
 #### crc32c
@@ -267,7 +269,8 @@ Install the minimal development tools:
 ```bash
 sudo zypper refresh && \
 sudo zypper install --allow-downgrade -y cmake gcc gcc-c++ git gzip \
-        libcurl-devel libopenssl-devel make tar wget
+        libcurl-devel libopenssl-devel make nlohmann_json \
+        tar wget
 ```
 
 #### crc32c
@@ -383,7 +386,7 @@ Install the minimal development tools:
 sudo apt update && \
 sudo apt install -y build-essential cmake git gcc g++ cmake \
         libc-ares-dev libc-ares2 libcurl4-openssl-dev libssl-dev make \
-        pkg-config tar wget zlib1g-dev
+        nlohmann-json-dev pkg-config tar wget zlib1g-dev
 ```
 
 #### crc32c
@@ -547,6 +550,21 @@ sudo make install
 sudo ldconfig
 ```
 
+#### nlohmann_json
+
+Ubuntu-16.04 does not provide a package for nlohmann_json. Manually install
+this library:
+
+```bash
+cd $HOME/Downloads
+wget -q https://github.com/nlohmann/json/archive/v3.6.1.tar.gz
+tar -xf json-3.6.1.tar.gz
+cd $HOME/Downloads/json-3.6.1
+cmake H. -Bcmake-out
+cmake --build cmake-out -- -j $(nproc)
+sudo cmake --build cmake-out --target install
+```
+
 #### google-cloud-cpp
 
 Finally we can install `google-cloud-cpp`.
@@ -566,7 +584,6 @@ sudo cmake --build . --target install
 ### Ubuntu (14.04 - Trusty Tahr)
 
 Install the minimal development tools.
-
 We use the `ubuntu-toolchain-r` PPA to get a modern version of CMake:
 
 ```bash
@@ -699,6 +716,21 @@ make -j $(nproc)
 sudo make install
 ```
 
+#### nlohmann_json
+
+Ubuntu:trusty does not provide a package for nlohmann_json. Manually install
+this library:
+
+```bash
+cd $HOME/Downloads
+wget -q https://github.com/nlohmann/json/archive/v3.6.1.tar.gz
+tar -xf json-3.6.1.tar.gz
+cd $HOME/Downloads/json-3.6.1
+cmake H. -Bcmake-out
+cmake --build cmake-out -- -j $(nproc)
+sudo cmake --build cmake-out --target install
+```
+
 #### google-cloud-cpp
 
 We can now compile and install `google-cloud-cpp`.
@@ -730,7 +762,7 @@ prevent you from compiling against openssl-1.1.0.
 
 ```bash
 sudo apt update && \
-sudo apt install -y build-essential cmake git gcc g++ cmake \
+sudo apt install -y build-essential cmake git gcc g++ json-devel cmake \
         libc-ares-dev libc-ares2 libcurl4-openssl-dev libssl1.0-dev make \
         pkg-config tar wget zlib1g-dev
 ```
@@ -820,7 +852,7 @@ sudo yum install -y centos-release-scl
 sudo yum-config-manager --enable rhel-server-rhscl-7-rpms
 sudo yum makecache && \
 sudo yum install -y automake cmake3 curl-devel gcc gcc-c++ git libtool \
-        make openssl-devel pkgconfig tar wget which zlib-devel
+        make json-devel openssl-devel pkgconfig tar wget which zlib-devel
 ln -sf /usr/bin/cmake3 /usr/bin/cmake && ln -sf /usr/bin/ctest3 /usr/bin/ctest
 ```
 

README.md

@@ -122,14 +122,15 @@ of these tools we test with are:
 
 #### Libraries
 
-The libraries also depend on gRPC, libcurl, and the dependencies of those
+The libraries also depend on gRPC, libcurl, nlohmann-json and the dependencies of those
 libraries. The Google Cloud C++ Client libraries are tested with the following
 versions of these dependencies:
 
 | Library | Minimum version |
 | ------- | --------------- |
 | gRPC    | v1.16.x |
 | libcurl | 7.47.0  |
+| nljson  | 3.6.1   |
 
 #### Tests
 
@@ -156,7 +157,7 @@ sudo yum install -y centos-release-scl
 sudo yum-config-manager --enable rhel-server-rhscl-7-rpms
 sudo yum makecache && \
 sudo yum install -y automake cmake3 curl-devel gcc gcc-c++ git libtool \
-        make openssl-devel pkgconfig tar wget which zlib-devel
+        make json-devel openssl-devel pkgconfig tar wget which zlib-devel
 ln -sf /usr/bin/cmake3 /usr/bin/cmake && ln -sf /usr/bin/ctest3 /usr/bin/ctest
 ```
 
@@ -179,7 +180,7 @@ prevent you from compiling against openssl-1.1.0.
 sudo apt update && \
 sudo apt install -y build-essential cmake git gcc g++ cmake \
         libc-ares-dev libc-ares2 libcurl4-openssl-dev libssl1.0-dev make \
-        pkg-config tar wget zlib1g-dev
+        nlohmann-json3 pkg-config tar wget zlib1g-dev
 ```
 
 ### Fedora (30)
@@ -192,7 +193,7 @@ sudo apt install -y build-essential cmake git gcc g++ cmake \
 ```bash
 sudo dnf makecache && \
 sudo dnf install -y cmake gcc-c++ git make openssl-devel pkgconfig \
-        zlib-devel
+        json-devel zlib-devel
 ```
 
 ### OpenSUSE (Tumbleweed)
@@ -205,7 +206,8 @@ sudo dnf install -y cmake gcc-c++ git make openssl-devel pkgconfig \
 ```bash
 sudo zypper refresh && \
 sudo zypper install --allow-downgrade -y cmake gcc gcc-c++ git gzip \
-        libcurl-devel libopenssl-devel make tar wget zlib-devel
+        libcurl-devel libopenssl-devel make nlohmann_json \
+        tar wget zlib-devel
 ```
 
 ### OpenSUSE (Leap)
@@ -218,7 +220,7 @@ sudo zypper install --allow-downgrade -y cmake gcc gcc-c++ git gzip \
 ```bash
 sudo zypper refresh && \
 sudo zypper install --allow-downgrade -y cmake gcc gcc-c++ git gzip \
-        libcurl-devel libopenssl-devel make tar wget
+        libcurl-devel libopenssl-devel make nlohmann_json tar wget
 ```
 
 ### Ubuntu (18.04 - Bionic Beaver)
@@ -232,7 +234,7 @@ sudo zypper install --allow-downgrade -y cmake gcc gcc-c++ git gzip \
 sudo apt update && \
 sudo apt install -y build-essential cmake git gcc g++ cmake \
         libc-ares-dev libc-ares2 libcurl4-openssl-dev libssl-dev make \
-        pkg-config tar wget zlib1g-dev
+        nlohmann-json-dev pkg-config tar wget zlib1g-dev
 ```
 
 ### Ubuntu (16.04 - Xenial Xerus)
@@ -249,6 +251,19 @@ sudo apt install -y build-essential cmake git gcc g++ cmake \
         pkg-config tar wget zlib1g-dev
 ```
 
+Ubuntu-16.04 does not provide a package for nlohmann_json. Manually install
+this library:
+
+```bash
+cd $HOME/Downloads
+wget -q https://github.com/nlohmann/json/archive/v3.6.1.tar.gz
+tar -xf json-3.6.1.tar.gz
+cd $HOME/Downloads/json-3.6.1
+cmake H. -Bcmake-out
+cmake --build cmake-out -- -j $(nproc)
+sudo cmake --build cmake-out --target install
+```
+
 ### Ubuntu (14.04 - Trusty Tahr)
 
 [![Kokoro install ubuntu-trusty status][kokoro-install-ubuntu-trusty-shield]][kokoro-install-ubuntu-trusty-link]
@@ -294,6 +309,19 @@ export OPENSSL_ROOT_DIR=/usr/local/ssl
 export PKG_CONFIG_PATH=/usr/local/ssl/lib/pkgconfig
 ```
 
+Ubuntu:trusty does not provide a package for nlohmann_json. Manually install
+this library:
+
+```bash
+cd $HOME/Downloads
+wget -q https://github.com/nlohmann/json/archive/v3.6.1.tar.gz
+tar -xf json-3.6.1.tar.gz
+cd $HOME/Downloads/json-3.6.1
+cmake H. -Bcmake-out
+cmake --build cmake-out -- -j $(nproc)
+sudo cmake --build cmake-out --target install
+```
+
 #### macOS (using brew)
 
 ```bash

ci/benchmarks/Dockerfile

@@ -17,7 +17,7 @@ FROM ubuntu:bionic AS google-cloud-cpp-dependencies
 RUN apt update && \
     apt install -y build-essential cmake git gcc g++ cmake \
         libc-ares-dev libc-ares2 libcurl4-openssl-dev libssl-dev make \
-        pkg-config tar wget zlib1g-dev
+        nlohmann-json-dev pkg-config tar wget zlib1g-dev
 
 # #### crc32c
 

ci/kokoro/docker/Dockerfile.centos

@@ -29,6 +29,7 @@ RUN yum makecache && yum install -y \
     gcc \
     gcc-c++ \
     git \
+    json-devel \
     make \
     openssl-devel \
     python \

ci/kokoro/docker/Dockerfile.fedora

@@ -28,6 +28,7 @@ RUN dnf makecache && dnf install -y \
     doxygen \
     gcc-c++ \
     git \
+    json-devel \
     libcurl-devel \
     libcxx-devel \
     libcxxabi-devel \

ci/kokoro/docker/Dockerfile.fedora-install

@@ -30,6 +30,7 @@ RUN dnf makecache && dnf install -y \
     git \
     grpc-devel \
     grpc-plugins \
+    json-devel \
     libcurl-devel \
     libcxx-devel \
     libcxxabi-devel \

ci/kokoro/docker/Dockerfile.ubuntu

@@ -36,6 +36,7 @@ RUN apt update && \
         libtool \
         lsb-release \
         make \
+        nlohmann-json-dev \
         pkg-config \
         python-pip \
         shellcheck \

ci/kokoro/docker/Dockerfile.ubuntu-install

@@ -37,6 +37,7 @@ RUN apt update && \
         libtool \
         lsb-release \
         make \
+        nlohmann-json-dev \
         pkg-config \
         python-pip \
         shellcheck \

ci/kokoro/docker/Dockerfile.ubuntu-trusty

@@ -51,6 +51,16 @@ RUN apt update && apt install -y python-dev python-pip
 RUN pip install --upgrade pip
 RUN pip install flask httpbin gevent gunicorn crc32c
 
+# Ubuntu:trusty does not provide a package for nlohmann_json. Manually install
+# this library:
+WORKDIR /var/tmp/build
+RUN wget -q https://github.com/nlohmann/json/archive/v3.6.1.tar.gz
+RUN tar -xf json-3.6.1.tar.gz
+WORKDIR /var/tmp/build/json-3.6.1
+RUN cmake H. -Bcmake-out
+RUN cmake --build cmake-out -- -j $(nproc)
+RUN cmake --build cmake-out --target install
+
 # Install the Cloud Bigtable emulator and the Cloud Bigtable command-line
 # client.  They are used in the integration tests.
 COPY . /var/tmp/ci

ci/kokoro/install/Dockerfile.centos

@@ -31,7 +31,7 @@ RUN yum install -y centos-release-scl
 RUN yum-config-manager --enable rhel-server-rhscl-7-rpms
 RUN yum makecache && \
     yum install -y automake cmake3 curl-devel gcc gcc-c++ git libtool \
-        make openssl-devel pkgconfig tar wget which zlib-devel
+        make json-devel openssl-devel pkgconfig tar wget which zlib-devel
 RUN ln -sf /usr/bin/cmake3 /usr/bin/cmake && ln -sf /usr/bin/ctest3 /usr/bin/ctest
 # ```
 

ci/kokoro/install/Dockerfile.debian

@@ -31,7 +31,7 @@ FROM debian:${DISTRO_VERSION} AS devtools
 
 # ```bash
 RUN apt update && \
-    apt install -y build-essential cmake git gcc g++ cmake \
+    apt install -y build-essential cmake git gcc g++ json-devel cmake \
         libc-ares-dev libc-ares2 libcurl4-openssl-dev libssl1.0-dev make \
         pkg-config tar wget zlib1g-dev
 # ```

ci/kokoro/install/Dockerfile.fedora

@@ -35,7 +35,7 @@ RUN dnf makecache && \
 
 # ```bash
 RUN dnf makecache && \
-    dnf install -y grpc-devel grpc-plugins \
+    dnf install -y grpc-devel grpc-plugins json-devel \
         libcurl-devel protobuf-compiler tar wget zlib-devel
 # ```
 

ci/kokoro/install/Dockerfile.opensuse

@@ -31,7 +31,8 @@ RUN zypper refresh && \
 
 # ```bash
 RUN zypper refresh && \
-    zypper install -y grpc-devel gzip libcurl-devel pkg-config tar wget
+    zypper install -y grpc-devel gzip libcurl-devel nlohmann_json \
+        pkg-config tar wget
 # ```
 
 # #### crc32c

ci/kokoro/install/Dockerfile.opensuse-leap

@@ -22,7 +22,8 @@ FROM opensuse/leap:${DISTRO_VERSION} AS devtools
 # ```bash
 RUN zypper refresh && \
     zypper install --allow-downgrade -y cmake gcc gcc-c++ git gzip \
-        libcurl-devel libopenssl-devel make tar wget
+        libcurl-devel libopenssl-devel make nlohmann_json \
+        tar wget
 # ```
 
 # #### crc32c

ci/kokoro/install/Dockerfile.ubuntu

@@ -26,7 +26,7 @@ FROM ubuntu:${DISTRO_VERSION} AS devtools
 RUN apt update && \
     apt install -y build-essential cmake git gcc g++ cmake \
         libc-ares-dev libc-ares2 libcurl4-openssl-dev libssl-dev make \
-        pkg-config tar wget zlib1g-dev
+        nlohmann-json-dev pkg-config tar wget zlib1g-dev
 # ```
 
 # #### crc32c

ci/kokoro/install/Dockerfile.ubuntu-trusty

@@ -154,6 +154,21 @@ RUN make -j $(nproc)
 RUN make install
 # ```
 
+# #### nlohmann_json
+
+# Ubuntu:trusty does not provide a package for nlohmann_json. Manually install
+# this library:
+
+# ```bash
+WORKDIR /var/tmp/build
+RUN wget -q https://github.com/nlohmann/json/archive/v3.6.1.tar.gz
+RUN tar -xf json-3.6.1.tar.gz
+WORKDIR /var/tmp/build/json-3.6.1
+RUN cmake H. -Bcmake-out
+RUN cmake --build cmake-out -- -j $(nproc)
+RUN cmake --build cmake-out --target install
+# ```
+
 FROM devtools AS install
 
 # #### google-cloud-cpp

ci/kokoro/install/Dockerfile.ubuntu-xenial

@@ -108,6 +108,21 @@ RUN make install
 RUN ldconfig
 # ```
 
+# #### nlohmann_json
+
+# Ubuntu-16.04 does not provide a package for nlohmann_json. Manually install
+# this library:
+
+# ```bash
+WORKDIR /var/tmp/build
+RUN wget -q https://github.com/nlohmann/json/archive/v3.6.1.tar.gz
+RUN tar -xf json-3.6.1.tar.gz
+WORKDIR /var/tmp/build/json-3.6.1
+RUN cmake H. -Bcmake-out
+RUN cmake --build cmake-out -- -j $(nproc)
+RUN cmake --build cmake-out --target install
+# ```
+
 FROM devtools AS install
 
 # #### google-cloud-cpp