Made microservices easier to locally develop.

.vscode/launch.json

@@ -0,0 +1,20 @@
+{
+	// Use IntelliSense to learn about possible attributes.
+	// Hover to view descriptions of existing attributes.
+	// For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+	"version": "0.2.0",
+	"configurations": [
+		{
+			"name": "Attach to api-server container",
+			"type": "node",
+			"request": "attach",
+			// should match the exposed debug address specified in docker-compose
+			"address": "localhost",
+			"port": 9229,
+			"protocol": "inspector",
+			// you typically copy the src folder into a location in docker...specify this mapping.
+			"localRoot": "${workspaceFolder}/api-server/src",
+			"remoteRoot": "/usr/src/app"
+		}
+	]
+}

README.md

@@ -1,21 +1,52 @@
 # Horus
 
-Monitoring containerized microservices with a centralized logging architecture.
+A test project for learning microservices observability through: **centralized logging** and **distributed tracing**.
 
-## Dependencies
+## Requirements
 
 - Docker Compose v1.23.2
+- OSX or GNU/Linux operating system
 
-## Setup
+## Development Setup
 
-1. Signup with an ELK SaaS provider like [Logz.io](logz.io) to obtain an authentication token. Then for each microservice, rename `example.env` to `.env` and supply the needed secrets.
+1. Clone this repo and open the root folder in an IDE like *Visual Studio Code*.
 
-2. Run the following commands.
+2. For each microservice, rename `example.env` to `.env` and supply the needed secrets.
 
-		docker-compose build --pull
-		docker-compose up -d --force-recreate
-		
-3. Then log into your ELK SaaS and view your microservices logs.
+3. Start all microservices in *development mode*.
+
+        docker-compose -f docker-compose.dev.yml \
+            up -d --build
+
+    > Development mode is important for 2 reasons.
+    > - Changes to a service's source files will automatically restart/rebuild the docker service to show the changes.
+    > - You can attach a remote debugger from your IDE to the docker process for seemless debugging like placing breakpoints and watching variables.
+    > - NOTE: When you edit a service's source files, the docker process will restart, severing your remote debugger connection. So, you'd need to reattach the debugger again.
+
+4. Attach the IDE's debugger to the desired service. Follow these steps in Visual Studio Code: *shift+cmd+D > Select a debug configuration > F5*.
+    > All Visual Studio Code debug configurations are stored in *.vscode/launch.json*. You can modify configs as you see fit.
+
+### Useful dev commands
+
+    # list all running services
+    docker-compose -f docker-compose.dev.yml ps
+
+    # stop all services
+    docker-compose -f docker-compose.dev.yml down
+
+    # restart only all [or specific] service
+    docker-compose -f docker-compose.dev.yml \
+        up -d --no-deps --build [service-name]
+
+    # tail logs from all [or specific] service
+    docker-compose logs -f [service-name]
+
+## Production Setup
+
+TODO
+
+- Signup with an ELK SaaS provider like [Logz.io](logz.io) to obtain an authentication token. Then for each microservice, rename `example.env` to `.env` and supply the needed secrets.
+- Then log into your ELK SaaS and view your microservices logs.
 
 ## Project Documentation
 
@@ -27,6 +58,16 @@ I wrote an accompanying [article](https://hackernoon.com/monitoring-containerize
 
 ## Notes
 
+- You can update a single service/container while the entire suite is running using the following command
+
+		docker-compose -f docker-compose.dev.yml \
+			up -d --no-deps --build <service_name>
+
+		docker-compose -f docker-compose.prod.yml \
+			up -d --no-deps --build <service_name>
+
+	> `--build` recreates the container from its image/dockerfile and `--no-deps` ensures dependent services aren't affected.
+
 ### Docker Networking
 
 By default each containerized process runs in an isolated network namespace. For inter-container communication, place them in the same network namespace...as seen in *docker-compose.yml*.
@@ -36,8 +77,21 @@ By default each containerized process runs in an isolated network namespace. For
 1. You can pass secrets for a microservice using the `env_file` attribute in *docker-compose.yml*.
 2. Microservices can communicate using their service names if they are in the same docker network.
 
+### How do you debug an app running in a container (i.e breakpoints and watch variables etc.)?
+?
+- You can tail the logs from all services using `docker-compose [-f <file>] logs -f`.
+
 ### Improvement Considerations
 
 1. **Name Duplication:** The value of the `API_SERVER_ADDRESS` variable in *user-simulator/.env* depends on the service name `api-server` specified in *docker-compose.yml*. If we rename the service, we must also change the variable. Is there a way to make this DRY?
 
-2. In the log-shipper container, I had to install a logz.io-specific plugin. Can't this step be eliminated since fluentd is capable of connecting to https endpoints without plugins?
+2. In the log-shipper container, I had to install a logz.io-specific plugin. Can't this step be eliminated since fluentd is capable of connecting to https endpoints without plugins?
+
+3. Use sub-second precision for fluentd timestamps (probably best to use nanoseconds.)
+
+## Some References
+
+https://medium.com/lucjuggery/docker-in-development-with-nodemon-d500366e74df
+https://blog.risingstack.com/how-to-debug-a-node-js-app-in-a-docker-container/
+https://codefresh.io/docker-tutorial/debug_node_in_docker/
+https://code.visualstudio.com/docs/editor/debugging

api-server/.gitignore

@@ -1,4 +1,4 @@
 .env
-/node_modules
+node_modules
 npm-debug.log
 .DS_Store

api-server/Dockerfile

@@ -5,9 +5,11 @@ WORKDIR /usr/src/app
 # optimization to only rebuild npm modules iff package[-lock].json changes
 COPY src/package*.json ./
 
+# TODO: only install nodemon if some arg is set to 'dev'
+RUN npm install -g nodemon
 # For production `RUN npm install --only=production`
 RUN npm install
 
 COPY src .
 
-CMD ["npm", "start"]
+CMD ["node", "."]

api-server/example.env

@@ -1 +1 @@
-PORT=
+# TODO

api-server/src/app.js

@@ -1,19 +1,17 @@
-// const dotenv = require('dotenv')
-// if (process.env.NODE_ENV !== 'production') {
-// 	const result = dotenv.config()
-// 	if (result.error) {
-// 		throw result.error
-// 	}
-// }
-
 const app = require('express')()
 const uuid = require('uuid/v1')
 
 app.use('/api/v1/tokens', (req, res) => {
 	console.log(`Handling request for token`)
 	res.json({token: uuid()})
 })
-
-const server = app.listen(process.env.PORT, () => {
+app.use('/api/v1/whereami', (req, res) => {
+	// TODO: get geolocation info from IP address
+	// TODO: get weather info from geolocation
+	// TODO: return everything
+	let data = {'info': null}
+	res.json(data)
+})
+const server = app.listen(process.env.PORT || 3000, () => {
 	console.log(`Listening on ${ server.address().address }:${ server.address().port }`)
 })