1# Build scripts that publish pre-compiled protoc artifacts
2``protoc`` is the compiler for ``.proto`` files. It generates language bindings
3for the messages and/or RPC services from ``.proto`` files.
4
5Because ``protoc`` is a native executable, the scripts under this directory
6build and publish a ``protoc`` executable (a.k.a. artifact) to Maven
7repositories. The artifact can be used by build automation tools so that users
8would not need to compile and install ``protoc`` for their systems.
9
10## Versioning
11The version of the ``protoc`` artifact must be the same as the version of the
12Protobuf project.
13
14## Artifact name
15The name of a published ``protoc`` artifact is in the following format:
16``protoc-<version>-<os>-<arch>.exe``, e.g., ``protoc-3.0.0-alpha-3-windows-x86_64.exe``.
17
18## System requirement
19Install [Apache Maven](http://maven.apache.org/) if you don't have it.
20
21The scripts only work under Unix-like environments, e.g., Linux, MacOSX, and
22Cygwin or MinGW for Windows. Please see ``README.md`` of the Protobuf project
23for how to set up the build environment.
24
25## To install artifacts locally
26The following command will install the ``protoc`` artifact to your local Maven repository.
27```
28$ mvn install
29```
30
31## Cross-compilation
32The Maven script will try to detect the OS and the architecture from Java
33system properties. It's possible to build a protoc binary for an architecture
34that is different from what Java has detected, as long as you have the proper
35compilers installed.
36
37You can override the Maven properties ``os.detected.name`` and
38``os.detected.arch`` to force the script to generate binaries for a specific OS
39and/or architecture. Valid values are defined as the return values of
40``normalizeOs()`` and ``normalizeArch()`` of ``Detector`` from
41[os-maven-plugin](https://github.com/trustin/os-maven-plugin/blob/master/src/main/java/kr/motd/maven/os/Detector.java).
42Frequently used values are:
43- ``os.detected.name``: ``linux``, ``osx``, ``windows``.
44- ``os.detected.arch``: ``x86_32``, ``x86_64``
45
46For example, MingGW32 only ships with 32-bit compilers, but you can still build
4732-bit protoc under 64-bit Windows, with the following command:
48```
49$ mvn install -Dos.detected.arch=x86_32
50```
51
52## To push artifacts to Maven Central
53Before you can upload artifacts to Maven Central repository, make sure you have
54read [this page](http://central.sonatype.org/pages/apache-maven.html) on how to
55configure GPG and Sonatype account.
56
57You need to perform the deployment for every platform that you want to
58support. DO NOT close the staging repository until you have done the
59deployment for all platforms. Currently the following platforms are supported:
60- Linux (x86_32 and x86_64)
61- Windows (x86_32 and x86_64) with
62 - Cygwin with MinGW compilers (both x86_32 and x86_64)
63 - MSYS with MinGW32 (x86_32 only)
64- MacOSX (x86_32 and x86_64)
65
66Use the following command to deploy artifacts for the host platform to a
67staging repository.
68```
69$ mvn clean deploy -P release
70```
71It creates a new staging repository. Go to
72https://oss.sonatype.org/#stagingRepositories and find the repository, usually
73in the name like ``comgoogle-123``.
74
75You will want to run this command on a different platform. Remember, in
76subsequent deployments you will need to provide the repository name that you
77have found in the first deployment so that all artifacts go to the same
78repository:
79```
80$ mvn clean deploy -P release -Dstaging.repository=comgoogle-123
81```
82
83A 32-bit artifact can be deployed from a 64-bit host with
84``-Dos.detected.arch=x86_32``
85
86When you have done deployment for all platforms, go to
87https://oss.sonatype.org/#stagingRepositories, verify that the staging
88repository has all the binaries, close and release this repository.
89
90### Tips for deploying on Linux
91We build on Centos 6.6 to provide a good compatibility for not very new
92systems. We have provided a ``Dockerfile`` under this directory to build the
93environment. It has been tested with Docker 1.6.1.
94
95To build a image:
96```
97$ docker build -t protoc-artifacts .
98```
99
100To run the image:
101```
102$ docker run -it --rm=true protoc-artifacts
103```
104
105The Protobuf repository has been cloned into ``/protobuf``.
106
107### Tips for deploying on Windows
108Under Windows the following error may occur: ``gpg: cannot open tty `no tty':
109No such file or directory``. This can be fixed by configuring gpg through an
110active profile in ``.m2\settings.xml`` where also the Sonatype password is
111stored:
112```xml
113<settings>
114  <servers>
115    <server>
116      <id>ossrh</id>
117      <username>[username]</username>
118      <password>[password]</password>
119    </server>
120  </servers>
121  <profiles>
122    <profile>
123      <id>gpg</id>
124      <properties>
125        <gpg.executable>gpg</gpg.executable>
126        <gpg.passphrase>[password]</gpg.passphrase>
127      </properties>
128    </profile>
129  </profiles>
130  <activeProfiles>
131    <activeProfile>gpg</activeProfile>
132  </activeProfiles>
133</settings>
134```
135
136### Tested build environments
137We have successfully built artifacts on the following environments:
138- Linux x86_32 and x86_64:
139 - Centos 6.6 (within Docker 1.6.1)
140 - Ubuntu 14.04.2 64-bit
141- Windows x86_32: MSYS with ``mingw32-gcc-g++ 4.8.1-4`` on Windows 7 64-bit
142- Windows x86_64: Cygwin64 with ``mingw64-x86_64-gcc-g++ 4.8.3-1`` on Windows 7 64-bit
143- Mac OS X x86_32 and x86_64: Mac OS X 10.9.5
144