switch home-manager from master to stable version (#1594)

contrib/nix/README.md

@@ -10,11 +10,17 @@ we declare it, then it works. see [sandbox.nix] file for details.
 
 it install software on /nix directory, and run service on launchpad(darwin) and systemd(linux).
 
+NOTE: for linux, ensure 'systemd --user' process running.
+
 
 ## Roadmap
-currently i already run all service on mac os. 
-linux os will be tested and supportd will come sooner.
-  
+
+- [X] support mac and linux
+- [ ] add environment check script
+- [ ] add datahub nix package
+- [ ] add datahub[gms, frontend, pipeline] service module
+- [ ] add nixops distributed deploy
+
 
 ## Quickstart
 1.  install nix and channel
@@ -23,20 +29,31 @@ linux os will be tested and supportd will come sooner.
   sudo install -d -m755 -o $(id -u) -g $(id -g) /nix
   curl https://nixos.org/nix/install | sh
   
-  nix-channel --add https://nixos.org/channels/nixos-20.03 nixos-20.03
-  nix-channel --update nixos-20.03
+  nix-channel --add https://nixos.org/channels/nixos-20.03 nixpkgs
+  nix-channel --update nixpkgs
 ```
 
 2. install home-manager
 
 ```
-  nix-channel --add https://github.com/clojurians-org/home-manager/archive/master.tar.gz home-manager
-  nix-channel --update
-  nix-shell '<home-manager>' -A install
+  nix-channel --add https://github.com/clojurians-org/home-manager/archive/v1.0.0.tar.gz home-manager
+  nix-channel --update home-manager
+  NIX_PATH=~/.nix-defexpr/channels nix-shell '<home-manager>' -A install
 ```
 
 3. setup environment, and well done!
 ```
-  export NIX_PATH=~/.nix-defexpr/channels
-  home-manager -I home-manager=<home-manager> -f sandbox.nix switch
+  NIX_PATH=~/.nix-defexpr/channels home-manager -f sandbox.nix switch
+```
+
+## Client connect
+```
+mysql                     => mysql -u root -S /nix/var/run/mysqld.sock
+postgresql                => psql -h /nix/var/run postgres
+elasticsearch             => curl http://localhost:9200
+neo4j                     => cypher-shell -uneo4j -pneo4j
+zookeeper                 => zkCli.sh
+kafka                     => kafka-topics.sh --bootstrap-server localhost:9092 --list
+confluent schema-registry => curl http://localhost:8081
+
 ```

contrib/nix/sandbox.nix

@@ -40,7 +40,6 @@
     # package = pkgs.mysql80 ;
     package = pkgs.mysql57 ;
     dataDir = "/opt/nix-module/data/mysql" ;
-    unixSocket = "/opt/nix-module/run/mysql.sock" ;
   } ;
 
   services.elasticsearch = {