Added cron support

Dockerfile

@@ -14,7 +14,7 @@ USER deno
 # These steps will be re-run upon each file change in your working directory:
 ADD src/ .
 # Compile the main app so that it doesn't need to be compiled each startup/entry.
-RUN deno cache index.ts
+RUN deno cache index*.ts
 
 # "deno" is entrypoint, so all commands are arguments to deno
-CMD [ "run", "--allow-read", "--allow-write", "--allow-net", "--allow-env", "index.ts" ]
+CMD [ "run", "--allow-read", "--allow-run", "--allow-env", "index.docker.ts" ]

README.md

@@ -13,13 +13,20 @@ This project's purpose was mostly to test Deno and learn Typescript (I have a lo
 ## How to use
 [![Docker stats](https://dockeri.co/image/sherex/ddns-client)](https://hub.docker.com/r/sherex/ddns-client/)
 ### Docker Compose
+Use environment variable `DDNS_CRON` to schedule it.
+
 1. Create a `docker-compose.yml` file
 ```yml
 # docker-compose.yml
 version: "3.7"
 services:
   ddns_client:
     container_name: ddns-client
+    environment: 
+      - GD_KEY=YOUR_KEY_HERE
+      - GD_SECRET=YOUR_SECRET_HERE
+      - DDNS_CRON=1 */60 * * * *
+      - DDNS_LOGLEVEL=info
     image: sherex/ddns-client:latest
     volumes:
       - "./config:/app/config"
@@ -37,10 +44,11 @@ $ docker-compose up # -d # Add '-d' switch to run as daemon
 Check out [configuration](#Configuration) further down.
 
 ### Docker
+Use environment variable `DDNS_CRON` to schedule it.
 ```sh
 # Creates the config directory and places config.json inside
 # Replace $PWD with %cd% on Windows
-$ docker run -v $PWD/config:/app/config --name ddns-client sherex/ddns-client
+$ docker run -v $PWD/config:/app/config -d -e "DDNS_CRON=1 */60 * * * *" --name ddns-client sherex/ddns-client
 
 # Edit 'config/config.json' - I recommend VSCode to use the JSON schema.
 
@@ -86,6 +94,14 @@ It can be one of the values (case insensitive):
 
 The default is `info`.
 
+### Cron
+The `index.docker.ts` file starts `index.ts` as a subprocess and exits when it's done.  
+But if you set the environment variable `DDNS_CRON` to a cron string, it will stay running and start `index.ts` every time the cron string matches.
+
+The docker container on [Docker Hub](https://hub.docker.com/r/sherex/ddns-client/) uses this file.
+
+It uses [deno_cron](https://deno.land/x/deno_cron) for the cron jobs.
+
 ## TODO
 - [X] Move config from .env to config.json
   - [X] Use config.json

docker-compose.yml

@@ -2,6 +2,11 @@ version: "3.7"
 services:
   ddns_client:
     container_name: ddns-client
-    image: sherex/ddns-client:latest
+    environment: 
+      - GD_KEY=YOUR_KEY_HERE
+      - GD_SECRET=YOUR_SECRET_HERE
+      - DDNS_CRON=1 */60 * * * *
+      - DDNS_LOGLEVEL=INFO
+    build: ./
     volumes:
       - "./config:/app/config"

src/index.docker.ts

@@ -0,0 +1,46 @@
+import "https://deno.land/x/dotenv/load.ts";
+import { cron, stop, start } from 'https://deno.land/x/deno_cron/cron.ts'
+import { log } from './lib/logger.ts'
+import { exists } from './lib/exists.ts'
+
+let mainPath = "index.ts"
+
+if (exists("./index.ts") === 'file') mainPath = "./index.ts"
+else if (exists("./src/index.ts") === 'file') mainPath = "./src/index.ts"
+
+const cronString = Deno.env.get('DDNS_CRON')
+let timesFailed = 0
+
+if (cronString) {
+  log('info', ["index.docker", "start", "with cron", cronString])
+
+  stop()
+  await run() // Make sure it runs once when started
+  start()
+
+  cron(cronString, () => run())
+} else {
+  stop()
+  log('info', ["index.docker", "start", "single-run"])
+  await run()
+  Deno.exit(0)
+}
+
+async function run() {
+  const process = Deno.run({
+    cmd: ["deno", "run", "--allow-read", "--allow-write", "--allow-net", "--allow-env", mainPath],
+    env: Deno.env.toObject()
+  })
+  const status = await process.status()
+  if (status.code === 0) {
+    timesFailed = 0
+    log('info', ["index.docker", "success"])
+    return
+  } else if (timesFailed < 3) {
+    timesFailed++
+    log('error', ["index.docker", "failed", "total times failed", String(timesFailed)])
+  } else {
+    log("warn", ["index.docker", "too many failed attempts", String(timesFailed), "exiting"])
+    Deno.exit(1)
+  }
+}