Merge pull request #36 from dangeroustech/general-updates

General Best Practise Updates

.github/dependabot.yml

@@ -9,3 +9,12 @@ updates:
       - dependencies
       - github-actions
 
+  - package-ecosystem: docker
+    directory: /
+    schedule:
+      interval: weekly
+    open-pull-requests-limit: 10
+    labels:
+      - dependencies
+      - docker
+

.gitignore

@@ -0,0 +1,2 @@
+sbom.spdx.json
+results.sarif

Dockerfile

@@ -5,8 +5,17 @@ ARG VERSION=1.12.2
 RUN apt-get update -qq && apt-get install -qq --no-install-recommends -y \
     ca-certificates=20230311+deb12u1 \
     curl=7.88.1-10+deb12u14
-RUN ARCH_MAPPING=$([ "$TARGETARCH" = "amd64" ] && echo amd64 || ([ "$TARGETARCH" = "arm64" ] && echo arm64 || echo "$TARGETARCH")) \
-    && curl -sSL -o zerotier-one.deb "${PACKAGE_BASEURL}/zerotier-one_${VERSION}_${ARCH_MAPPING}.deb"
+RUN set -e; \
+    DETECTED_ARCH="${TARGETARCH:-}"; \
+    if [ -z "$DETECTED_ARCH" ]; then DETECTED_ARCH="$(dpkg --print-architecture)"; fi; \
+    case "$DETECTED_ARCH" in \
+      amd64|x86_64) ARCH_MAPPING=amd64 ;; \
+      arm64|aarch64) ARCH_MAPPING=arm64 ;; \
+      armhf|armv7*) ARCH_MAPPING=armhf ;; \
+      *) echo "Unsupported architecture: $DETECTED_ARCH" >&2; exit 1 ;; \
+    esac; \
+    echo "Downloading ZeroTier: arch=$ARCH_MAPPING version=$VERSION"; \
+    curl -fsSL -o zerotier-one.deb "${PACKAGE_BASEURL}/zerotier-one_${VERSION}_${ARCH_MAPPING}.deb"
 
 FROM debian:12.6
 ARG VERSION

README.md

@@ -20,21 +20,21 @@ You also need to add a static route into ZeroTier so that the traffic is routed
 
 ### Docker Compose
 
-**You need to edit the `ZT_NETWORKS` and `ARCH` variable in the `docker-compose.yml` file first to add your networks and make sure your acrhitecture is correct (see [this page](http://download.zerotier.com/debian/buster/pool/main/z/zerotier-one/) for examples, usually either amd64 or arm64)**
+Edit the `ZT_NETWORKS` variable in `docker-compose.yml` to add your networks. Multi-arch images are published automatically; no architecture changes are needed.
 
 Easiest way to bring up is via Docker Compose. Rename `docker-compose.yml.example` to `docker-compose.yml` and run `docker compose up -d`.
 
-If you want to disable bridging, set `ZT_BRIDGE=false`. This can be done after the initial networks have been joined (just change the environment variable in the `docker-compose.yml` file and run `), as the ZeroTier config persists but IPTables forwarding is done on each container startup.
+If you want to disable bridging, set `ZT_BRIDGE=false`. This can be done after the initial networks have been joined (just change the environment variable in the `docker-compose.yml` file and restart), as the ZeroTier config persists but IPTables forwarding is done on each container startup.
 
 ### OG Docker
 
 `docker build -t zerotierbridge .`
 
-`docker run --privileged -e ZT_NETWORKS=NETWORK_1 NETWORK_2 -e ZT_BRIDGE=true zerotierbridge:latest`
+`docker run --cap-add NET_ADMIN --cap-add NET_RAW --sysctl net.ipv4.ip_forward=1 -e ZT_NETWORKS="NETWORK_1 NETWORK_2" -e ZT_BRIDGE=true zerotierbridge:latest`
 
 Add your network ID(s) into the `ZT_NETWORKS` argument, space separated.
 
-Disable bridging by passing `ZT_BRIDGE=false`. This can be done after the initial networks have been joined (just rebuild the container), as the ZeroTier config persists but IPTables forwarding is done on each container startup.
+Disable bridging by passing `ZT_BRIDGE=false`. This can be done after the initial networks have been joined (just restart the container), as the ZeroTier config persists but IPTables forwarding is done on each container startup.
 
 #### Persistent Storage
 
@@ -42,8 +42,6 @@ If you would like the container to retain the same ZeroTier client ID on reboot,
 
 `docker run --privileged -e ZT_NETWORKS=NETWORK_ID_HERE ZT_BRIDGE=true -v zt_config:/var/lib/zerotier-one/ zerotierbridge:latest`
 
-#### Caveat: Architecture
+#### Notes
 
-If you need to run this on a device with different architecture (a raspberry pi, for instance), then just edit line 3 of the Dockerfile.
-
-If you were using a Raspberry Pi 4, you would change this to `ARCH=arm64` and the container will pull the correct ZeroTier installer.
+If your host requires additional privileges for networking, you may need to add device and capabilities in your runtime configuration. The provided Docker Compose example includes `cap_add: [NET_ADMIN, NET_RAW]` and `sysctls` for IP forwarding.

docker-compose.yml.example

@@ -5,11 +5,15 @@ services:
     container_name: zerotierbridge
     image: registry.dangerous.tech/dangeroustech/zerotierbridge
     restart: always
-    privileged: true
+    cap_add:
+      - NET_ADMIN
+      - NET_RAW
+    sysctls:
+      net.ipv4.ip_forward: "1"
     volumes:
       - zt_config:/var/lib/zerotier-one
     environment:
-      - ZT_NETWORKS=NETWORK_ID_1 NETWORK_ID_2 NETWORK_ID_3
-      - ZT_BRIDGE=true
+      ZT_NETWORKS: "NETWORK_ID_1 NETWORK_ID_2 NETWORK_ID_3"
+      ZT_BRIDGE: "true"
 volumes:
   zt_config:

entrypoint.sh

@@ -1,15 +1,22 @@
 #!/bin/sh
 
-grepzt() {
-  (find /proc -name exe | xargs -I{} readlink {}) 2>/dev/null | grep -q zerotier-one
-  return $?
+set -eu
+
+terminate() {
+  # Try to terminate zerotier-one gracefully
+  if [ -n "${ZT_PID:-}" ]; then
+    kill -TERM "$ZT_PID" 2>/dev/null || true
+    wait "$ZT_PID" 2>/dev/null || true
+  fi
 }
+trap terminate INT TERM
 
 echo "starting zerotier"
 setsid /usr/sbin/zerotier-one &
+ZT_PID=$!
 
-while ! grepzt
-do
+# Wait for zerotier to be responsive
+until zerotier-cli info >/dev/null 2>&1; do
   echo "zerotier hasn't started, waiting a second"
   sleep 1
 done
@@ -17,34 +24,34 @@ done
 # Set IPTables to allow NATting
 sysctl -w net.ipv4.ip_forward=1 > /dev/null
 
-echo "joining networks: $ZT_NETWORKS"
+echo "joining networks: ${ZT_NETWORKS:-}"
 
-for n in $ZT_NETWORKS
-do
+for n in ${ZT_NETWORKS:-}; do
   echo "joining $n"
 
-  while ! zerotier-cli join "$n"
-  do 
+  until zerotier-cli join "$n"; do
     echo "joining $n failed; trying again in 1s"
     sleep 1
   done
 
-  if [ "$ZT_BRIDGE" = "true" ]
-  then
-    echo "Configuring iptables on $(zerotier-cli get $n portDeviceName)"
-    PHY_IFACE=eth0; ZT_IFACE=$(zerotier-cli get $n portDeviceName)
+  if [ "${ZT_BRIDGE:-true}" = "true" ]; then
+    ZT_IFACE=$(zerotier-cli get "$n" portDeviceName)
+    PHY_IFACE=eth0
+    echo "Configuring iptables on ${ZT_IFACE}"
 
-    iptables -t nat -A POSTROUTING -o $PHY_IFACE -j MASQUERADE
-    iptables -t nat -A POSTROUTING -o $ZT_IFACE -j MASQUERADE
-    iptables -A FORWARD -i $PHY_IFACE -o $ZT_IFACE -j ACCEPT
-    iptables -A FORWARD -i $ZT_IFACE -o $PHY_IFACE -j ACCEPT
+    # idempotent rules
+    iptables -t nat -C POSTROUTING -o "$PHY_IFACE" -j MASQUERADE 2>/dev/null || iptables -t nat -A POSTROUTING -o "$PHY_IFACE" -j MASQUERADE
+    iptables -t nat -C POSTROUTING -o "$ZT_IFACE" -j MASQUERADE 2>/dev/null || iptables -t nat -A POSTROUTING -o "$ZT_IFACE" -j MASQUERADE
+    iptables -C FORWARD -i "$PHY_IFACE" -o "$ZT_IFACE" -j ACCEPT 2>/dev/null || iptables -A FORWARD -i "$PHY_IFACE" -o "$ZT_IFACE" -j ACCEPT
+    iptables -C FORWARD -i "$ZT_IFACE" -o "$PHY_IFACE" -j ACCEPT 2>/dev/null || iptables -A FORWARD -i "$ZT_IFACE" -o "$PHY_IFACE" -j ACCEPT
   fi
 done
 
-# Give ZT a second realise it's online
+# Give ZT a second to realise it's online
 sleep 10
 
 # Print Client Info
-echo "$(zerotier-cli info)"
+zerotier-cli info || true
 
-sleep infinity
+# Keep the container running while zerotier-one is alive
+wait "$ZT_PID"

results.sarif

@@ -1,16 +0,0 @@
-{
-  "version": "2.1.0",
-  "$schema": "https://json.schemastore.org/sarif-2.1.0-rtm.5.json",
-  "runs": [
-    {
-      "tool": {
-        "driver": {
-          "name": "Grype",
-          "version": "0.63.0",
-          "informationUri": "https://github.com/anchore/grype"
-        }
-      },
-      "results": []
-    }
-  ]
-}