Adicionando seção com explicação para executar mútiplos SGAs a partir

de um mesmo diretório de instalação, compartilhando mesmos arquivos
sgad.sh e sgad.cfg.
 -  Proposta da solução apresentada para o grupo do BRSiOP.

[SOMA-4111]
[SOMA-4102]
[SOMA-2554]

README.md

@@ -66,6 +66,67 @@ host sandbox. The SSH data transfer configuration can be enable with posix drive
 Add **csgrid_id_rsa** private key in /home/csgrid/.ssh CSGrid server directory and fill **csgrid_id_rsa.pub** 
 file content in SGA csgrid home directory _.ssh/authorized_keys_ file. 
 
+## Multiple SGAs with same instalation directory
+
+Multiple SGAs can be run from the same installation directory. In this case, we 
+have a installation directory shared among all SGA machines via NFS. 
+All SGAs machines share the same script sgad.sh and configuration file sgad.cfg. 
+To run multiple SGAs in this environment, the following changes can be done:
+
+sgad.sh
+```bash
+#!/bin/bash
+export CSBASE_SERVER="http://localhost:40409"
+export SGAD_HOST=$HOSTNAME
+export SGAD_PORT=40100
+export SGAD_NAME=$HOSTNAME
+export SGAD_PLATFORM="Linux44_64"
+export SERVER_DATA_DIR="/mnt/csgrid_data"
+
+timestamp=$(date +%Y%m%d%H%M%S)
+logsdir="logs"
+
+[[ ! -e $logsdir ]] && echo "mkdir $logsdir" && mkdir $logsdir
+
+logfile="logs/${HOSTNAME}_sgad_${timestamp}.log"
+
+configfile=${1}
+if [ -z ${configfile} ]; then
+   echo "Using default file configuration" > ${logfile};
+   configfile=sgad.cfg
+fi
+hostruntimedir="/tmp/${SGAD_NAME}"
+sgadruntimedir="${hostruntimedir}/sgad"
+runtimesandboxdir="${sgadruntimedir}/sandbox"
+
+[[ ! -e $hostruntimedir ]] && echo "mkdir $hostruntimedir..." && mkdir $hostruntimedir
+[[ ! -e $sgadruntimedir ]] && echo "mkdir $sgadruntimedir..." && mkdir $sgadruntimedir
+[[ ! -e $runtimesandboxdir ]] && echo "mkdir $runtimesandboxdir..." && mkdir $runtimesandboxdir
+
+eval $(luarocks path --bin)
+sgad ${configfile} 2>&1 | tee -a "${logfile}"
+```
+ 
+sgad.cfg
+```lua
+csbase_server = os.getenv("CSBASE_SERVER")
+platform = os.getenv("SGAD_PLATFORM") or "Linux44_64"
+sgad_host = os.getenv("SGAD_HOST")
+sgad_port = tonumber(os.getenv("SGAD_PORT"))
+sga_name = os.getenv("SGAD_NAME")
+status_interval_s = 10
+exec_polling_interval_s = 5
+register_retry_s = 3
+project_root_dir = os.getenv("SERVER_DATA_DIR") .. "/projects"
+algorithm_root_dir = os.getenv("SERVER_DATA_DIR") .. "/algorithms"
+runtime_data_dir = "/tmp/" .. os.getenv("SGAD_NAME") .. "/sgad"
+sandbox_root_dir = "/tmp/" .. os.getenv("SGAD_NAME") .. "/sgad/sandbox"
+driver = "sga.driver.posix"
+resources = {
+  "docker"
+}
+``` 
+
 ## Install
 
 Requirements: