Feature/detect docker range

packages/ytl-linux-digabi2-examnet/Makefile

@@ -1,5 +1,5 @@
 NAME := ytl-linux-digabi2-examnet
-VERSION := 0.0.19
+VERSION := 0.0.20
 
 DEPENDENCIES := \
 	--depends apt \

packages/ytl-linux-digabi2-examnet/README.md

@@ -4,31 +4,38 @@
 
 This is a proof-of-concept of a procedure which creates proper network settings
 for Abitti 2 exam server. The setup requires that the server has two network devices
- * A WAN device connected to the internet. At the moment this is used to get a
-   SSL certificate and DNS address for the server. According to the initial plans
-   it might be later used e.g. to download exam items and upload candidate data.
-   At the moment a wireless device is good enough for a WAN connection.
- * A LAN device connected to the closed local area network. This is an Abitti 1
-   style network without any external DHCP/DNS servers. After executing the script
-   the server starts working as a DHCP/DNS server for the LAN.
+
+- A WAN device connected to the internet. At the moment this is used to get a
+  SSL certificate and DNS address for the server. According to the initial plans
+  it might be later used e.g. to download exam items and upload candidate data.
+  At the moment a wireless device is good enough for a WAN connection.
+- A LAN device connected to the closed local area network. This is an Abitti 1
+  style network without any external DHCP/DNS servers. After executing the script
+  the server starts working as a DHCP/DNS server for the LAN.
 
 ## Usage
 
 The script is executed from command line:
 
-`$ sudo ytl-linux-digabi2-examnet`
+```bash
+sudo ytl-linux-digabi2-examnet
+```
 
 If executed without parameters, it asks the WAN and LAN devices as well as the
 server number. It is possible to run multiple servers in one LAN but they must have
 different server numbers.
 
 It is possible to supply the three parameters in command line:
 
-`ytl-linux-digabi2-examnet wan-device lan-device server-number`
+```bash
+ytl-linux-digabi2-examnet wan-device lan-device server-number`
+```
 
 Example:
 
-`$ sudo ytl-linux-digabi2-examnet wlo1 eth0 1`
+```bash
+sudo ytl-linux-digabi2-examnet wlo1 eth0 1
+```
 
 It is also possible to run the script in GUI mode (parameter `--gui`). In this case the
 parameters are asked with Zenity.
@@ -37,7 +44,9 @@ parameters are asked with Zenity.
 
 Following command should restore the system to pristine state:
 
-`$ sudo ytl-linux-digabi2-examnet --remove`
+```bash
+sudo ytl-linux-digabi2-examnet --remove
+```
 
 It removes the settings files created by this script. It also removes all NetworkManager
 connections which have a name starting with `yo-`. This is the prefix used by the
@@ -47,6 +56,27 @@ script to create the static connection for the local network.
 
 The debugging messages can be printed to a given file:
 
-`$ DEBUG=/tmp/whatta.log sudo ytl-linux-digabi2-examnet`
+```bash
+DEBUG=/tmp/whatta.log sudo ytl-linux-digabi2-examnet
+```
 
 The list of exit codes can be found in the script.
+
+## Building locally
+
+For macOS, install fpm e.g. with Ruby gem:
+
+```bash
+# Install Ruby and gem, set path
+brew install ruby
+echo 'export PATH="/opt/homebrew/opt/ruby/bin:$PATH"' >> ~/.zshrc
+echo 'export PATH="$(gem environment gemdir)/bin:$PATH"' >> ~/.zshrc
+# Install fpm
+gem install fpm
+```
+
+Then build the Debian package:
+
+```bash
+make deb
+```

packages/ytl-linux-digabi2-examnet/templates/docker-daemon.json.template

@@ -1,3 +1,7 @@
 {
-  "dns": ["${DOCKER_BRIDGE_NETWORK_DNS_RESOLVER_IP}"]
+  "dns": ["${DOCKER_NETWORK_DNS_RESOLVER_IP}"],
+  "default-address-pools":
+  [
+    {"base": "${DOCKER_NETWORK_POOL_BASE_IP}/16", "size":26}
+  ]
 }

packages/ytl-linux-digabi2-examnet/ytl-linux-digabi2-examnet

@@ -35,7 +35,6 @@ readonly PARAM_SERVER_NUMBER=$3
 readonly PARAM_SERVER_FRIENDLY_NAME=$4
 
 readonly NETWORK_DEVICE_FILTER_RE="^docker|^br|^veth|^lo$"
-readonly DOCKER_BRIDGE_NETWORK_DNS_RESOLVER_IP="172.17.0.1"
 
 readonly PATH_TEMPLATES=/etc/ytl-linux-digabi2-examnet/templates
 readonly PATH_RESOLVED=/etc/systemd/resolved.conf.d
@@ -283,14 +282,27 @@ function check_server_number() {
     fi
 }
 
-function get_lan_ip_prefix() {
-    _IP_WAN=$1
+function get_ip_prefix() {
+    echo "${1%.*.*}."
+}
 
-    if [[ "$_IP_WAN" =~ ^192\.168\. ]]; then
-        $BIN_ECHO "10.0."
-    else
-        $BIN_ECHO "192.168."
-    fi
+function get_available_ip_range() {
+    _ALLOWED_IP_RANGES=("10.0." "192.168." "172.17.")
+
+    for range in "${_ALLOWED_IP_RANGES[@]}"; do
+        _USED=false
+        for reserved in "$@"; do
+            if [[ $reserved == $range* ]]; then
+                _USED=true
+                break
+            fi
+        done
+        if [[ "$_USED" == false ]]; then
+            # return the first available
+            echo "$range"
+            return
+        fi
+    done
 }
 
 function write_file() {
@@ -674,10 +686,14 @@ export IP_WAN
 export IP_LAN
 export SERVER_NUMBER
 
-IP_LAN_PREFIX=$(get_lan_ip_prefix "$IP_WAN")
+IP_LAN_PREFIX=$(get_ip_prefix "$IP_LAN")
 export IP_LAN_PREFIX
 
-export DOCKER_BRIDGE_NETWORK_DNS_RESOLVER_IP
+DOCKER_NETWORK_PREFIX=$(get_available_ip_range "$IP_WAN" "$IP_LAN")
+DOCKER_NETWORK_DNS_RESOLVER_IP="$DOCKER_NETWORK_PREFIX".0.1
+export DOCKER_NETWORK_DNS_RESOLVER_IP
+DOCKER_NETWORK_POOL_BASE_IP="$DOCKER_NETWORK_PREFIX".0.0
+export DOCKER_NETWORK_POOL_BASE_IP
 
 debug "SUBNETS_PER_SERVER: $CONST_SUBNETS_PER_SERVER"