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Make sure erlang is installed and in path. http://www.erlang.org/downloads
NOTE: You can test it by typing erl in the terminal of your operating system.
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Download it from here or just clone this repo.
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Extract it on a desired folder.
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Enter to the folder
erlang_chat_test-masterorerlang_chat_test; if you clonned it using git clone. If you are using the shell just type the equivalent command for your system.
cd erlang_chat_test-master/
- Build the test builder helper.
erl -make
- Run the test builder helper
erl -s make_test
Make sure you are in the root directory of the test erlang_chat_test and type this command into the terminal to start the main server.
erl -noshell -name [email protected] -pa server -config server/config/main -setcookie secure123 -s chat_server
You need to open more terminals to be able to have many instances of clients and servers, always stay in the root folder of the test in all terminal before running any command.
This will run the backup server.
erl -noshell -name [email protected] -pa server -config server/config/backup -setcookie secure123 -s chat_server
It is also possible to use -sname in both servers to configure short-name address type. See server_name_type in client.config to allow clients to connect to the server using short-names.
Open as many terminals as you want in the root directory of the test and try the following commands one for each terminal get as many clients A and B as you want. 'A' clients will try to connect to the main server according with its configuration in client.config. 'B' clients will connect to the backup server and will use clientb.config configuration file.
erl -pa client -config client/config/client -s chat_client
erl -pa client -config client/config/clientb -s chat_client
Before running the tests make sure you have zero clients connected to the servers, you must close all terminals that are running any client or just use logout(). on all of them. You should also make sure you have both main and backup servers running, see Section 3. Starting the main and backup servers, then open two shells one for Client A and the other for Client B then type the following in one shell:
erl -pa client -config client/config/client -s chat_client -s tests_helper auto_login_for_tests
And in the other shell type:
erl -pa client -config client/config/clientb -s chat_client -s tests_helper run_tests
The tests will start and hopefully run successfully. Both clients will try to login to both servers, one will login to main server and the other to the backup server and they will be able to interact with each other, create chat, groups and send messages. This also test distribution.
You can see the test coverage by opening the web page generated by the test framework after the test is finished located in tests_results/index.html. You must click on > client.tests.tests_SUITE < link, then on > Coverage log < link.
First of all, you need to build the plt database:
dialyzer --build_plt --output_plt dialyzer.plt --apps erts kernel stdlib
dialyzer --add_to_plt --plt dialyzer.plt -r ./client
dialyzer --add_to_plt --plt dialyzer.plt -r ./server
Then you can run dialyzer checks:
dialyzer --plt dialyzer.plt -r ./client
dialyzer --plt dialyzer.plt -r ./server
Running xref is quite simple too:
erl -noshell -s xref_runner
In erlang distributed system two different distributed nodes have different configurations. Two configurations files are provided in this example for main and backup servers.
The main.config configuration setups the main server but also sets the option {sync_nodes_optional, ['[email protected]']} to the backup server node address. A small change has to be made for backup.config file to set the {sync_nodes_optional, ['[email protected]']} to the main server node address.
For editing configurations for main and backup server open this files main.config and backup.config located under server/config directory.
Edit main and backup servers name/address to match your system:
*{distributed, [{chat_server, ['[email protected]', {'[email protected]'}]}]},
{sync_nodes_optional, ['[email protected]']},*
This uses fully qualified node names but you can use short-names too. See client.config to change the server_name_type to allow clients to connect to the server using short-names.
To edit the client configuration, open the file client.config located under client/config folder.
Make sure {server_name, '[email protected]'} matches your main or backup server node address.
This option {server_name_type, longnames} specifies if you are using fully qualified names or short-names in the server.
The following {server_cookie, 'secure123'} defines the cookie that will be used to connect to the server. See section: 3. Starting the servers.
There are also other client configurations provided in this example, such as clientb.config to start a client that will connect to the backup server.
NOTE: After editing the configurations you must modify the parameter -name or -sname in the commands to start the servers, to match your server address.
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Make sure git is installed. https://git-scm.com/book/en/v2/Getting-Started-Installing-Git
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Make sure erlang is installed. http://www.erlang.org/downloads
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gnome-terminal
sudo apt install gnome-terminal
git clone https://github.com/StartSWest/erlang_chat_test.git
cd erlang_chat_test/
./compile
You can use the following commands to interact with the test.
./compile will compile it.
./serve will start both main and backup servers.
./start-client will start a client that will connect to main server according to its default configuration.
./start-clientb will start a client that will connect to backup server according to its default configuration.
./run-tests will run all tests.
./dialyzer for dialyzer analysis.
./xref for xref analysis.
In the current architecture there is no data persistence if any of the servers goes down. A second server will take over the application and start it clean without no data. The users get disconnected from the server if they were connected to the server that went down. A second clientb.config configuration is provided in this example to start clients that will connect to the backup server. For this kind of setup to work as expected a proxy must be configured in front of the servers so the clients always connect to the same address regardless of which server will take over when the other goes down.
There is a second setup I can think of and that is manually starting the applications in both main and server nodes. The last server to start ask to one of the running server to sync the data, also it could be possible to start pg2 global progress group to join the new server so any subsequent messages sent from the users can be send to all servers in the group. I didn't implement this way because of the simplexes and elegance of the first one which is native erlang distribution with global processes.
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login(User).: Logs in a user to the server.
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chat_with(TargetUser).: Sends a chat request to a target user. Returns a chat id that both users can use to chat with each other.
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send(ChatId, Message).: Sends a message to the other user involved in the chat request created by 'chat_with'.
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sendg(GroupName, Message).: Sends a message all users in the group.
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create_group(GroupName).: Creates a chat group to send messages to many users at the same time. See 'add_to_group' and 'sendg'.
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add_to_group(GroupName, User).: Adds a user to a chat group.
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remove_from_group(GroupName, User).: Removes a user from a chat group.
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logout().: Logs out the current user from the server.
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help().: Shows this help.