6 files changed, 85 insertions, 4 deletions
diff --git a/src/docker-in-docker/devcontainer-feature.json b/src/docker-in-docker/devcontainer-feature.json
index a8022cf..95a6a2c 100644
--- a/src/docker-in-docker/devcontainer-feature.json
+++ b/src/docker-in-docker/devcontainer-feature.json
@@ -1,6 +1,6 @@
 {
     "id": "docker-in-docker",
-    "version": "1.0.7",
+    "version": "1.0.8",
     "name": "Docker (Docker-in-Docker)",
     "documentationURL": "https://github.com/devcontainers/features/tree/main/src/docker-in-docker",
     "description": "Create child containers *inside* a container, independent from the host's docker instance. Installs Docker extension in the container along with needed CLIs.",
@@ -33,6 +33,12 @@
             "type": "boolean",
             "default": true,
             "description": "Allow automatically setting the dockerd DNS server when the installation script detects it is running in Azure"
+        },
+        "dockerDefaultAddressPool": {
+            "type": "string",
+            "default": "",
+            "proposals": [],
+            "description": "Define default address pools for Docker networks. e.g. base=192.168.0.0/16,size=24"
         }
     },
     "entrypoint": "/usr/local/share/docker-init.sh",
diff --git a/src/docker-in-docker/install.sh b/src/docker-in-docker/install.sh
index c51e57c..fe4692f 100755
--- a/src/docker-in-docker/install.sh
+++ b/src/docker-in-docker/install.sh
@@ -12,6 +12,7 @@ DOCKER_VERSION=${VERSION:-"latest"} # The Docker/Moby Engine + CLI should match
 USE_MOBY=${MOBY:-"true"}
 DOCKER_DASH_COMPOSE_VERSION=${DOCKERDASHCOMPOSEVERSION:-"v1"} # v1 or v2
 AZURE_DNS_AUTO_DETECTION=${AZUREDNSAUTODETECTION:-"true"}
+DOCKER_DEFAULT_ADDRESS_POOL=${DOCKERDEFAULTADDRESSPOOL}
 
 ENABLE_NONROOT_DOCKER=${ENABLE_NONROOT_DOCKER:-"true"}
 USERNAME=${USERNAME:-"automatic"}
@@ -325,12 +326,13 @@ tee /usr/local/share/docker-init.sh > /dev/null \
 
 set -e
 
-AZURE_DNS_AUTO_DETECTION=$AZURE_DNS_AUTO_DETECTION
+AZURE_DNS_AUTO_DETECTION=${AZURE_DNS_AUTO_DETECTION}
+DOCKER_DEFAULT_ADDRESS_POOL=${DOCKER_DEFAULT_ADDRESS_POOL}
 EOF
 
 tee -a /usr/local/share/docker-init.sh > /dev/null \
 << 'EOF'
-dockerd_start="$(cat << 'INNEREOF'
+dockerd_start="AZURE_DNS_AUTO_DETECTION=${AZURE_DNS_AUTO_DETECTION} DOCKER_DEFAULT_ADDRESS_POOL=${DOCKER_DEFAULT_ADDRESS_POOL} $(cat << 'INNEREOF'
     # explicitly remove dockerd and containerd PID file to ensure that it can start properly if it was stopped uncleanly
     # ie: docker kill <ID>
     find /run /var/run -iname 'docker*.pid' -delete || :
@@ -377,10 +379,18 @@ dockerd_start="$(cat << 'INNEREOF'
         echo "Not setting dockerd DNS manually."
         CUSTOMDNS=""
     fi
+
     set -e
 
+    if [ -z "$DOCKER_DEFAULT_ADDRESS_POOL" ]
+    then
+        DEFAULT_ADDRESS_POOL=""
+    else
+        DEFAULT_ADDRESS_POOL="--default-address-pool $DOCKER_DEFAULT_ADDRESS_POOL"
+    fi
+
     # Start docker/moby engine
-    ( dockerd $CUSTOMDNS > /tmp/dockerd.log 2>&1 ) &
+    ( dockerd $CUSTOMDNS $DEFAULT_ADDRESS_POOL > /tmp/dockerd.log 2>&1 ) &
 INNEREOF
 )"
 
diff --git a/test/docker-in-docker/azureDnsAutoDetectionDisabled.sh b/test/docker-in-docker/azureDnsAutoDetectionDisabled.sh
new file mode 100644
index 0000000..d3f4159
--- /dev/null
+++ b/test/docker-in-docker/azureDnsAutoDetectionDisabled.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+
+set -e
+
+# Optional: Import test library
+source dev-container-features-test-lib
+
+# Definition specific tests
+check "dns flag should not be present" test ! "$(ps -ax | grep -E 'dockerd.+\-\-dns')"
+
+# Report result
+reportResults
+\ No newline at end of file
diff --git a/test/docker-in-docker/azureDnsAutoDetectionEnabled.sh b/test/docker-in-docker/azureDnsAutoDetectionEnabled.sh
new file mode 100644
index 0000000..e63a1f3
--- /dev/null
+++ b/test/docker-in-docker/azureDnsAutoDetectionEnabled.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+
+set -e
+
+# Optional: Import test library
+source dev-container-features-test-lib
+
+# Definition specific tests
+check "dns flag should be present" ps -ax | grep -E "dockerd.+\-\-dns"
+
+# Report result
+reportResults
+\ No newline at end of file
diff --git a/test/docker-in-docker/dockerDefaultAddressPool.sh b/test/docker-in-docker/dockerDefaultAddressPool.sh
new file mode 100644
index 0000000..8345357
--- /dev/null
+++ b/test/docker-in-docker/dockerDefaultAddressPool.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+
+set -e
+
+# Optional: Import test library
+source dev-container-features-test-lib
+
+# Definition specific tests
+check "default address pool setting set" ps -ax | grep -E "dockerd.+base=192.168.0.0/16,size=24"
+
+# Report result
+reportResults
+\ No newline at end of file
diff --git a/test/docker-in-docker/scenarios.json b/test/docker-in-docker/scenarios.json
new file mode 100644
index 0000000..d37053a
--- /dev/null
+++ b/test/docker-in-docker/scenarios.json
@@ -0,0 +1,29 @@
+{
+    "dockerDefaultAddressPool": {
+        "image": "mcr.microsoft.com/vscode/devcontainers/javascript-node:0-18",
+        "remoteUser": "node",
+        "features": {
+            "docker-in-docker": {
+                "dockerDefaultAddressPool": "base=192.168.0.0/16,size=24"
+            }
+        }
+    },
+    "azureDnsAutoDetectionEnabled": {
+        "image": "mcr.microsoft.com/vscode/devcontainers/javascript-node:0-18",
+        "remoteUser": "node",
+        "features": {
+            "docker-in-docker": {
+                "azureDnsAutoDetection": true
+            }
+        }
+    },
+    "azureDnsAutoDetectionDisabled": {
+        "image": "mcr.microsoft.com/vscode/devcontainers/javascript-node:0-18",
+        "remoteUser": "node",
+        "features": {
+            "docker-in-docker": {
+                "azureDnsAutoDetection": false
+            }
+        }
+    }
+}
+\ No newline at end of file