####install oracle-driver on centos/rhel
1.get file files as follow:
"github.com/wendal/go-oci8"
oracle-instantclient11.2-basic-11.2.0.1.0-1.x86_64.zip
oracle-instantclient11.2-sdk-11.2.0.1.0-1.x86_64.zip
pkgconfig-0.17.2.tar.bz2
2.install oracle-instantclient
unzip oracle-instantclient11.2-basic-11.2.0.1.0-1.x86_64.zip
unzip oracle-instantclient11.2-sdk-11.2.0.1.0-1.x86_64.zip
tar -zcvf instantclient_11_2.tgz instantclient_11_2
mv instantclient_11_2.tgz /usr/lib
cd /usr/lib
tar -zxvf instantclient_11_2.tgz
ln /usr/lib/instantclient_11_2/libclntsh.so.11.1 /usr/lib/libclntsh.so
ln /usr/lib/instantclient_11_2/libocci.so.11.1 /usr/lib/libocci.so
ln /usr/lib/instantclient_11_2/libociei.so /usr/lib/libociei.so
ln /usr/lib/instantclient_11_2/libnnz11.so /usr/lib/libnnz11.so
3.install okgconfig
tar -xvf pkgconfig-0.17.2.tar.bz2
cd ;./configure make make install
/usr/lib64/pkgconfig
vim oci8.pc
prefix=/usr/lib/instantclient_11_2
libdir=${prefix}
includedir=${prefix}/sdk/include
Name: OCI
Description: Oracle database engine
Version: 11.2
Libs: -L${libdir} -lclntsh
Libs.private:
Cflags: -I${includedir}
4.set your env path
export GOHOME=/docker/home/docker/go
export GOROOT=$GOHOME/go
export GOPATH=$GOHOME/myproject
export ORACLE_HOME=$GOHOME/instantclient_11_2
export TNS_ADMIN=$ORACLE_HOME/network/admin
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$ORACLE_HOME
export PKG_CONFIG_PATH=/usr/lib64/pkgconfig
PATH=$PATH:$HOME/bin:$GOROOT/bin
5.prepare tnsnames.ora
cd $GOHOME/instantclient_11_2
mkdir -p network/admin
cp your_tnsnames.ora ./
6.modify wendal/go-oci8
119 line ：(**C.OCIServer)(unsafe.Pointer(&conn.svc)),---》(**C.OCISvcCtx)(unsafe.Pointer(&conn.svc)),
136 line ：(*C.OCIServer)(c.svc),---》(*C.OCISvcCtx)(c.svc),
263 line ：(*C.OCIServer)(s.c.svc), (*C.OCISvcCtx)(s.c.svc),
383 line：(*C.OCIServer)(s.c.svc), (*C.OCISvcCtx)(s.c.svc),
cd db_exporter
vi config.ini;edit your conf
go build oracle_exporter.go
./oracle_exporter or ./oracle_exporter --port your_port