Add Q&A for 'protocol https not supported or disable in libcurl' issue

CHANGELOG.md

@@ -11,12 +11,13 @@ Please mark all change in change log and use the ticket from JIRA.
 - \#12 - Pure CPU version for Milvus
 - \#77 - Support table partition
 - \#226 - Experimental shards middleware for Milvus
-- \#314 - add Find FAISS in CMake
 
 ## Improvement
 - \#275 - Rename C++ SDK IndexType
 - \#284 - Change C++ SDK to shared library
 - \#260 - C++ SDK README
+- \#314 - add Find FAISS in CMake
+- \#310 - Add Q&A for 'protocol https not supported or disable in libcurl' issue
 
 ## Task
 

install.md

@@ -3,7 +3,10 @@
 ## Software requirements
 
 - Ubuntu 18.04 or higher
-- CMake 3.14 or higher
+- CMake 3.12 or higher
+
+##### For GPU version, you will also need:
+
 - CUDA 10.0 or higher
 - NVIDIA driver 418 or higher
 
@@ -12,17 +15,20 @@
 ### Step 1 Install dependencies
 
 ```shell
-$ cd [Milvus sourcecode path]/core
+$ cd [Milvus root path]/core
 $ ./ubuntu_build_deps.sh
 ```
 
 ### Step 2 Build
 
 ```shell
-$ cd [Milvus sourcecode path]/core
+$ cd [Milvus root path]/core
 $ ./build.sh -t Debug
 or 
 $ ./build.sh -t Release
+
+For GPU version, add -g option
+$ ./build.sh -g
 ```
 
 When the build is completed, all the stuff that you need in order to run Milvus will be installed under `[Milvus root path]/core/milvus`.
@@ -36,7 +42,7 @@ $ cd [Milvus root path]/core/milvus
 Add `lib/` directory to `LD_LIBRARY_PATH`
 
 ```
-$ export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/path/to/milvus/lib
+$ export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:[Milvus root path]/core/milvus/lib
 ```
 
 Then start Milvus server:
@@ -51,3 +57,15 @@ To stop Milvus server, run:
 ```shell
 $ ./stop_server.sh
 ```
+
+## Troubleshooting
+1. If you encounter the following error when compiling: 
+`protocol https not supported or disabled in libcurl`.
+First, make sure you have `libcurl4-openssl-dev` installed in your system.
+Then try reinstall CMake from source with `--system-curl` option:
+```
+$ ./bootstrap --system-curl 
+$ make 
+$ sudo make install
+```
+