Docker-in-docker: Updates docker-init with "pkill" (#711)

* Docker-in-docker: Updates docker-init with "pkill"

* pkill only if container didn't start at first

* pkill with condition

* add back sudo_if

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

 {
     "id": "docker-in-docker",
-    "version": "2.5.0",
+    "version": "2.6.0",
     "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.",

src/docker-in-docker/install.sh

@@ -362,8 +362,9 @@ 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'
+    # Stop dockerd and containerd in case they are already running
+    docker info > /dev/null 2>&1 && pkill dockerd && pkill containerd
     # 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 || :
     find /run /var/run -iname 'container*.pid' -delete || :
 
@@ -444,6 +445,16 @@ dockerd_start="AZURE_DNS_AUTO_DETECTION=${AZURE_DNS_AUTO_DETECTION} DOCKER_DEFAU
 INNEREOF
 )"
 
+sudo_if() {
+    COMMAND="$*"
+
+    if [ "$(id -u)" -ne 0 ]; then
+        sudo $COMMAND
+    else
+        $COMMAND
+    fi
+}
+
 retry_docker_start_count=0
 docker_ok="false"
 
@@ -469,6 +480,8 @@ do
     
     if [ "${docker_ok}" != "true" ]; then
         echo "(*) Failed to start docker, retrying..."
+        sudo_if pkill dockerd
+        sudo_if pkill containerd
     fi
     
     retry_docker_start_count=`expr $retry_docker_start_count + 1`