Merge pull request #117 from arulrajnet/env-support

[feature] Support for environmental substitution in config.json

Author: timothymiller

README.md

@@ -258,6 +258,20 @@ If you have multiple IP addresses and want to load balance between them, you can
 }
 ```
 
+### Docker environment variable support
+
+Define environmental variables starts with `CF_DDNS_` and use it in config.json
+
+For ex:
+
+```json
+{
+  "cloudflare": [
+    {
+      "authentication": {
+        "api_token": "${CF_DDNS_API_TOKEN}",
+```
+
 ### 🧹 Optional features
 
 `purgeUnknownRecords` removes stale DNS records from Cloudflare. This is useful if you have a dynamic DNS record that you no longer want to use. If you have a dynamic DNS record that you no longer want to use, you can set `purgeUnknownRecords` to `true` and the script will remove the stale DNS record from Cloudflare.

cloudflare-ddns.py

@@ -8,6 +8,8 @@
 
 __version__ = "1.0.2"
 
+from string import Template
+
 import json
 import os
 import signal
@@ -17,7 +19,8 @@
 import requests
 
 CONFIG_PATH = os.environ.get('CONFIG_PATH', os.getcwd())
-
+# Read in all environment variables that have the correct prefix
+ENV_VARS = {key: value for (key, value) in os.environ.items() if key.startswith('CF_DDNS_')}
 
 class GracefulExit:
     def __init__(self):
@@ -260,7 +263,10 @@ def updateIPs(ips):
     config = None
     try:
         with open(os.path.join(CONFIG_PATH, "config.json")) as config_file:
-            config = json.loads(config_file.read())
+            if len(ENV_VARS) != 0:
+                config = json.loads(Template(config_file.read()).safe_substitute(ENV_VARS))
+            else:
+                config = json.loads(config_file.read())
     except:
         print("😡 Error reading config.json")
         # wait 10 seconds to prevent excessive logging on docker auto restart

scripts/docker-build-all.sh

@@ -1,3 +1,4 @@
 #!/bin/bash
-docker buildx build --platform  linux/ppc64le,linux/s390x,linux/386,linux/arm/v6,linux/arm/v7,linux/arm64/v8,linux/amd64 --tag timothyjmiller/cloudflare-ddns:latest ../
+BASH_DIR=$(dirname $(realpath "${BASH_SOURCE}"))
+docker buildx build --platform  linux/ppc64le,linux/s390x,linux/386,linux/arm/v6,linux/arm/v7,linux/arm64/v8,linux/amd64 --tag timothyjmiller/cloudflare-ddns:latest ${BASH_DIR}/../
 # TODO: Support linux/riscv64

scripts/docker-build.sh

@@ -1,2 +1,3 @@
 #!/bin/bash
-docker build --platform linux/amd64 --tag timothyjmiller/cloudflare-ddns:latest ../
+BASH_DIR=$(dirname $(realpath "${BASH_SOURCE}"))
+docker build --platform linux/amd64 --tag timothyjmiller/cloudflare-ddns:latest ${BASH_DIR}/../

scripts/docker-publish.sh

@@ -1,2 +1,3 @@
 #!/bin/bash
-docker buildx build --platform linux/ppc64le,linux/s390x,linux/386,linux/arm/v6,linux/arm/v7,linux/arm64/v8,linux/amd64 --tag timothyjmiller/cloudflare-ddns:latest --push ../
+BASH_DIR=$(dirname $(realpath "${BASH_SOURCE}"))
+docker buildx build --platform linux/ppc64le,linux/s390x,linux/386,linux/arm/v6,linux/arm/v7,linux/arm64/v8,linux/amd64 --tag timothyjmiller/cloudflare-ddns:latest --push ${BASH_DIR}/../