As you know, we have developed a service in light-codegen called codegen-web to generate light-4j projects on the cloud without building and running light-codegen locally. As we have multiple release branches, we need to support users to generate code for the release they are working. It requires that we must support multiple APIs at the same time.
Codegen-web is built on top of light-hybrid-4j, which is very easy to support multiple versions of the same service running at the same time. However, it requires the UI to be implemented much more complicated to call different versions. To make the UI much simpler, we are going to run two or more codegen-web servers. At this moment, we are going to support release 1.6.x and 2.0.x at the same time.
To walk through how the codegen-web is built, we are going to split this tutorial into three different stages.
Develop and Test
It is for the light-codegen developers to work on the functionality of the codegen web and the view. There is no need to start multiple instances of the backend servers. There is no light-router, and consul server evolved.
To work on the codegen-web, you need first to check out and build the light-codegen. Let’s assume you are working on the master branch by default.
git clone https://github.com/networknt/light-codegen.git
mvn clean install
Once the build is done, we can start the codegen-web server.
java -jar target/codegen-web-server-shaded.jar
It will start the codegen-web server that is listening to 8080 port on HTTP. All the configuration files are using the default from resources/config.
Once the server is up and running, let’s start the React UI view.
It will start the Nodejs server with React hot reloading. All the calls with prefix /codegen will be proxied to the backend server on 8080. The Nodejs server is listening to port 3000.
Now you can update the UI code or update the backend code and test them together locally.
Although we have two instances of codegen web, we are sharing some code so that we can avoid changing code in two different branches. First, the UI code is the same for both 1.6.x and 2.0.x. Second, both instances are using the same codegen-server from light-portal. It is a docker container that can host both Java 8 1.6.x codegen-web jars and Java 11 2.0.x codegen-web jars.
To start the docker-compose locally with two instances of codegen-web, light-router, and the UI served by the light-router, we have created a folder in the light-config-test repo. You can check out the repo from networknt organization.
git clone https://github.com/networknt/light-config-test.git
The following files or directories are in the folder.
[email protected]:~/networknt/light-config-test/light-codegen$ ls -l
drwxr-xr-x 5 steve steve 4096 Jun 30 13:55 1_6_x
drwxr-xr-x 5 steve steve 4096 Jun 30 13:55 2_0_x
drwxrwxr-x 3 steve steve 4096 Jun 25 16:12 codegen-web
-rw-rw-r-- 1 steve steve 764 Jun 30 13:56 docker-compose-local.yaml
-rw-rw-r-- 1 steve steve 767 Jun 28 17:45 docker-compose.yaml
-rw-rw-r-- 1 steve steve 2180 Jun 30 13:54 README.md
drwxr-xr-x 4 steve steve 4096 Jun 30 13:55 router
The docker-compose-local.yaml is used to start the local docker-compose.
Let’s walk through this file to explain all the details. You will notice that service 2_0_x and 1_6_x are sharing the same image, which is the codegen-server from light-portal. For service 2_0_x, the config is read from ./2_0_x/local folder, and all the Java 11 codegen jar files are loading from the ./2_0_x/service folder. As the jar files are not checked into the GitHub, here is a list of jar files in the service folder. These jar file can be found in the light-codegen modules after the build.
[email protected]:~/networknt/light-config-test/light-codegen/2_0_x/service$ ls -l
-rw-r--r-- 1 steve steve 8033 Jun 30 17:56 codegen-core.jar
-rw-r--r-- 1 steve steve 3707 Jun 30 17:56 codegen-fwk.jar
-rw-r--r-- 1 steve steve 22401 Jun 30 17:56 codegen-web.jar
-rw-r--r-- 1 steve steve 468823 Jun 30 17:56 light-eventuate-4j-generator.jar
-rw-r--r-- 1 steve steve 177956 Jun 30 17:56 light-graphql-4j-generator.jar
-rw-r--r-- 1 steve steve 187058 Jun 30 17:56 light-hybrid-4j-generator.jar
-rw-r--r-- 1 steve steve 554372 Jun 30 17:56 light-rest-4j-generator.jar
These files are copied from light-codegen modules after the build from the master branch with JDK 11.
For service 1_6_x, the config is read from ./1_6_x/local folder, and all the Java 8 codegen jar files are loaded from the ./1_6_x/service folder. The name of the jars are the same as above; however, these jars are built from 1_6_x branch with JDK 8.
One environment variable DOCKER_HOST_IP is passed in as we are using host network and this environment variable will be used by the light-4j server to register to consul with the right IP address for each service.
For me, I have the following line in my .profile in my user’s home directory.
For the light-router instance, the config is loaded from ./router/local, and the UI React production code is loaded from ./codegen-web/build. To create the build folder, you need to go to the light-codegen/codegen-web/view and run the following build command.
npm run build
There would be a build folder created under the view folder. Copy the build folder to the ~/networknt/light-config-test/light-codegen/codegen-web
As we are using consul to register the codegen-web and discover these two services from light-router, we need to start the consul server locally first. You need to checkout light-docker first if you haven’t done so.
git clone https://github.com/networknt/light-docker.git
docker-compose -f docker-compose-consul.yml up -d
As our web server is running as a virtual host, we need to access it through the domain codegen.lightapi.net from the browser. For local testing, we can update the /etc/hosts to add an entry like this.
Please remember to comment out this line when we move to the cloud in the next step. Otherwise, the access always points to the local server, not the cloud server.
Once the above steps are done, start the docker-compose.
docker-compose -f docker-compose-local.yaml
If everything starts correctly, you can access the UI from the browser.
For the official production deployment, the light-codegen is deployed to the devops server with a docker-compose. Here is the content of the docker-compose.yaml
It is very similar to the local compose. The difference is that the config is loaded from the config folder instead of the local folder. Here are the steps to get it deployed to the devops server.
Once logged in, add the DOCKER_HOST_IP to the .profile
# export DOCKER_HOST_IP=192.168.1.144
Please change the IP to your IP on the server.
The next step is to enable ufw to allow the consul cluster to access this server on 8440 and 8439 on health endpoint.
sudo ufw status
sudo ufw enable
sudo ufw allow ssh
sudo ufw allow from xxx.xxx.xxx.186
sudo ufw allow from xxx.xxx.xxx.187
sudo ufw allow from xxx.xxx.xxx.188
The above firewall rules allow the TCP/IP connection from anywhere and the three nodes from the consul cluster to access this server on all ports. Please note that you need to allow the ssh once the ufw is enabled. Otherwise, you cannot log in to this server with ssh anymore once you are disconnected.
We need to copy the jdk11 and jdk8 jar files to the service folder under 2_0_x and 1_6_x with scp.
For example, the following command is for 2_0_x from the local
scp *.jar [email protected]:/home/steve/networknt/light-config-test/light-codegen/2_0_x/service
As the router is listening to port 8443, we need to set up the iptables to forward 443 to 8443 on this server. Please follow this tutorial to set it up.
Once everything is done, let’s start the docker-compose
docker-compose up -d
To learn how to use the codegen-web, please follow the video below.