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Move sources to `src` directory Fix `isLeader` method Fix autoscale loop, when none services for autoscale enabled
AMEST · Jan 4, 2022 · 136ccdd · 136ccdd
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diff --git a/Dockerfile b/Dockerfile
@@ -1,5 +1,5 @@
 FROM python:3.9-alpine
 RUN pip install flask requests docker
-COPY *.py /app/
+COPY src/*.py /app/
 WORKDIR /app
 ENTRYPOINT ["python","main.py"]
diff --git a/README.md b/README.md
@@ -1,9 +1,15 @@
 [![Autoscaller Build](https://github.com/AMEST/swarm-autoscaler/actions/workflows/main.yml/badge.svg?branch=master)](https://github.com/AMEST/swarm-autoscaler/actions/workflows/main.yml)
 ![hub.docker.com](https://img.shields.io/docker/pulls/eluki/swarm-service-autoscaler.svg)
 ![GitHub release (latest by date)](https://img.shields.io/github/v/release/amest/swarm-autoscaler)
+![GitHub](https://img.shields.io/github/license/amest/swarm-autoscaler)
 
 # Swarm Service Autoscaler
 
+## Links  
+* **[Docker hub](https://hub.docker.com/r/eluki/swarm-service-autoscaler)**
+
+***
+
 ## Description
 
 The project is an application that implements the ability to dynamically change the number of service instances under high load. The application receives all services that have the `swarm.autoscaler` label enabled, calculates the average value of the CPU utilization and, based on this, either increases the number of instances or decreases it.
@@ -13,16 +19,46 @@ But the minimum and maximum values of CPU utilization can be changed throu
 
 Also, for each service, you can set the maximum and minimum number of replicas to prevent a situation with an uncontrolled increase in the number of replicas (or too much decrease)
 
+## Usage
+
+1. Deploy Swarm Autoscaler using [`swarm-deploy.yml`](swarm-deploy.yml) from this repository
+2. Add label `swarm.autoscaler=true` for services you want to autoscale. 
+
+```yml
+deploy:
+  labels:
+    - "swarm.autoscaler=true"
+```
+
+For better resource management, it is recommended to add resource constraints to your service. Then it will definitely not eat more resources than necessary, and auto-scaling will work much better and will save resources in idle time.
+
+```yml
+deploy:
+  resources:
+    limits:
+      cpus: '0.50'
+```
+
 ## Configuration
 
-Service configure wia environment variable
+### Swarm Autoscaler configuration
 
-* `MIN_PERCENTAGE` - minimum service cpu utilization value in percent (0.0-100.0) for decrease service
-* `MAX_PERCENTAGE` - maximum service cpu utilization value in percent (0.0-100.0) for increase service
-* `DISCOVERY_DNSNAME` - swarm service name for in stack communication
-* `CHECK_INTERVAL` - interval between checks
-* `DRY_RUN` - noop mode for check service functional without enable inc or dec service replicas count
+_**The application is configured through environment variables**_
 
+| Setting                     | Default Value      | Description                                                                             |
+| --------------------------- | ------------------ | --------------------------------------------------------------------------------------- |
+| `AUTOSCALER_MIN_PERCENTAGE` | 25.0               | minimum service cpu utilization value in percent (0.0-100.0) for decrease service       |
+| `AUTOSCALER_MAX_PERCENTAGE` | 85.0               | maximum service cpu utilization value in percent (0.0-100.0) for increase service       |
+| `AUTOSCALER_DNSNAME`        | `tasks.autoscaler` | swarm service name for in stack communication                                           |
+| `AUTOSCALER_INTERVAL`       | 300                | interval between checks in seconds                                                      |
+| `AUTOSCALER_DRYRUN`         | false              | noop mode for check service functional without enable inc or dec service replicas count |
 
-## Usage
-...
+### Services configuration
+
+_**Services in docker swarm are configured via labels**_
+
+| Setting                | Value   | Description                                                                                                                |
+| ---------------------- | ------- | -------------------------------------------------------------------------------------------------------------------------- |
+| `swarm.autoscaler`     | `true`  | Required. This enables autoscaling for a service. Anything other than `true` will not enable it                            |
+| `swarm.autoscaler.min` | Integer | Optional. This is the minimum number of replicas wanted for a service. The autoscaler will not downscale below this number |
+| `swarm.autoscaler.max` | Integer | Optional. This is the maximum number of replicas wanted for a service. The autoscaler will not scale up past this number   |
diff --git a/container_controller.py → src/container_controller.py b/container_controller.py → src/container_controller.py
diff --git a/discovery.py → src/discovery.py b/discovery.py → src/discovery.py
diff --git a/docker_service.py → src/docker_service.py b/docker_service.py → src/docker_service.py
@@ -23,7 +23,7 @@ def isManager(self):
     def isLeader(self):
         if(not self.isManager()):
             return False
-        nodeList = self.dockerClient.nodes.list()
+        nodeList = self.dockerClient.nodes.list(filters={'role': 'manager'})
         nodeAddr = self.nodeInfo['Swarm']['NodeAddr']
         managerLeader = list(x for x in nodeList if x.attrs['ManagerStatus']['Leader'])[0]
         return managerLeader.attrs['ManagerStatus']['Addr'].startswith(nodeAddr)

diff --git a/main.py → src/main.py b/main.py → src/main.py
@@ -38,6 +38,7 @@ def autoscallerLoop():
                 time.sleep(60*10) # Wait 10 minute
                 continue
             services = SwarmService.getAutoscaleServices()
+            services = services if services != None else []
             logging.debug("Services len: %s", len(services))
             for service in services:
                 cpuLimit = SwarmService.getServiceCpuLimitPercent(service)