[docker-in-docker] - method 2 - daemon.json creation - #1023

src/docker-in-docker/devcontainer-feature.json

@@ -55,6 +55,11 @@
             "type": "boolean",
             "default": true,
             "description": "Install Compose Switch (provided docker compose is available) which is a replacement to the Compose V1 docker-compose (python) executable. It translates the command line into Compose V2 docker compose then runs the latter."
+        },
+        "ip6tables": {
+            "type": "boolean",
+            "default": true,
+            "description": "Disable ip6tables"
         }
     },
     "entrypoint": "/usr/local/share/docker-init.sh",

src/docker-in-docker/install.sh

@@ -20,6 +20,7 @@ INSTALL_DOCKER_COMPOSE_SWITCH="${INSTALLDOCKERCOMPOSESWITCH:-"true"}"
 MICROSOFT_GPG_KEYS_URI="https://packages.microsoft.com/keys/microsoft.asc"
 DOCKER_MOBY_ARCHIVE_VERSION_CODENAMES="bookworm buster bullseye bionic focal jammy noble"
 DOCKER_LICENSED_ARCHIVE_VERSION_CODENAMES="bookworm buster bullseye bionic focal hirsute impish jammy noble"
+IP6_TABLES="${IP6TABLES:-true}"
 
 # Default: Exit on any failure.
 set -e
@@ -480,11 +481,12 @@ set -e
 
 AZURE_DNS_AUTO_DETECTION=${AZURE_DNS_AUTO_DETECTION}
 DOCKER_DEFAULT_ADDRESS_POOL=${DOCKER_DEFAULT_ADDRESS_POOL}
+DOCKER_DEFAULT_IP6_TABLES=${IP6_TABLES}
 EOF
 
 tee -a /usr/local/share/docker-init.sh > /dev/null \
 << 'EOF'
-dockerd_start="AZURE_DNS_AUTO_DETECTION=${AZURE_DNS_AUTO_DETECTION} DOCKER_DEFAULT_ADDRESS_POOL=${DOCKER_DEFAULT_ADDRESS_POOL} $(cat << 'INNEREOF'
+dockerd_start="AZURE_DNS_AUTO_DETECTION=${AZURE_DNS_AUTO_DETECTION} DOCKER_DEFAULT_ADDRESS_POOL=${DOCKER_DEFAULT_ADDRESS_POOL} DOCKER_DEFAULT_IP6_TABLES=${DOCKER_DEFAULT_IP6_TABLES} $(cat << 'INNEREOF'
     # explicitly remove dockerd and containerd PID file to ensure that it can start properly if it was stopped uncleanly
     find /run /var/run -iname 'docker*.pid' -delete || :
     find /run /var/run -iname 'container*.pid' -delete || :
@@ -561,6 +563,13 @@ dockerd_start="AZURE_DNS_AUTO_DETECTION=${AZURE_DNS_AUTO_DETECTION} DOCKER_DEFAU
         DEFAULT_ADDRESS_POOL="--default-address-pool $DOCKER_DEFAULT_ADDRESS_POOL"
     fi
 
+    # Create the daemon.json file with the provided value
+    cat <<JSON_EOF > /etc/docker/daemon.json
+{
+    "ip6tables": $DOCKER_DEFAULT_IP6_TABLES
+}
+JSON_EOF
+
     # Start docker/moby engine
     ( dockerd $CUSTOMDNS $DEFAULT_ADDRESS_POOL > /tmp/dockerd.log 2>&1 ) &
 INNEREOF

test/docker-in-docker/dockerIp6tablesDisabledTest.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+set -e
+
+# Optional: Import test library
+source dev-container-features-test-lib
+
+ip6tablesCheck() {
+    if command -v ip6tables > /dev/null 2>&1; then
+        if ip6tables -L > /dev/null 2>&1; then
+            echo "✔️ ip6tables is enabled."
+        else
+            echo "❌ ip6tables is disabled."
+        fi
+    else
+        echo "❕ip6tables command not found. ❕"
+    fi
+}
+
+check "ip6tables" ip6tablesCheck
+
+reportResults

test/docker-in-docker/dockerIp6tablesEnabledTest.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+set -e
+
+# Optional: Import test library
+source dev-container-features-test-lib
+
+ip6tablesCheck() {
+    if command -v ip6tables > /dev/null 2>&1; then
+        if ip6tables -L > /dev/null 2>&1; then
+            echo "✔️ ip6tables is enabled."
+        else
+            echo "❌ ip6tables is disabled."
+        fi
+    else
+        echo "❕ip6tables command not found. ❕"
+    fi
+}
+
+check "ip6tables" ip6tablesCheck
+
+reportResults

test/docker-in-docker/scenarios.json

@@ -8,6 +8,22 @@
             }
         }
     },
+    "dockerIp6tablesDisabledTest": {
+        "image": "ubuntu:focal",
+        "features": {
+            "docker-in-docker": {
+                "ip6tables": false
+            }
+        }
+    },
+    "dockerIp6tablesEnabledTest": {
+        "image": "ubuntu:focal",
+        "features": {
+            "docker-in-docker": {
+                "ip6tables": true
+            }
+        }
+    },
     "dockerDefaultAddressPool": {
         "image": "mcr.microsoft.com/vscode/devcontainers/javascript-node:0-18",
         "remoteUser": "node",