General Troubleshooting Strategies¶
- Start by running
ddev poweroffto make sure all containers can start fresh.
- Temporarily disable firewalls, VPNs, network proxies, and virus checkers while you’re troubleshooting.
- Temporarily disable any proxies you’ve established in Docker’s settings.
ddev debug dockercheckand
ddev debug testto help sort out Docker problems.
- On macOS, check to make sure Docker Desktop or Colima are not out of disk space. In Settings (or Preferences) → Resources → Disk image size there should be ample space left; try not to let usage exceed 80% because the reported number can be unreliable. If it says zero used, something is wrong.
- If you have customizations like PHP overrides, nginx or Apache overrides, MySQL/PostgreSQL overrides, custom services, or
config.yamlchanges, please back them out while troubleshooting. It’s important to have the simplest possible environment while troubleshooting.
- Restart Docker. Consider a Docker factory reset in serious cases, which will destroy any databases you’ve loaded. See Docker Troubleshooting for more.
Try the simplest possible DDEV project (just as
ddev debug testdoes):
If that starts up fine, there may be an issue specifically with the project you’re trying to start.
Using DDEV with Other Development Environments
DDEV uses your system’s port 80 and 443 by default when projects are running. If you’re using another local development environment (like Lando or Docksal or a native setup), you can either stop the other environment or configure DDEV to use different ports. See troubleshooting for more detailed problem-solving. It’s easiest to stop the other environment when you want to use DDEV, and stop DDEV when you want to use the other environment.
Web Server Ports Already Occupied¶
DDEV may notify you about port conflicts with this message about port 80 or 443:
Failed to start yoursite: Unable to listen on required ports, localhost port 80 is in use
DDEV sometimes also has this error message that will alert you to port conflicts:
ERROR: for ddev-router Cannot start service ddev-router: Ports are not available: listen tcp 127.0.0.1:XX: bind: An attempt was made to access a socket in a way forbidden by its access permissions.
This means there’s another web server listening on the named port(s) and DDEV cannot access the port. The most common conflicts are on ports 80 and 443.
In some cases, the conflict could be over phpMyAdmin’s port 8036 or MailHog’s port 8025.
To resolve this conflict, choose one of three methods:
- If you’re using another local development environment (MAMP, WAMP, Lando, etc.) that uses these ports, consider stopping it.
- Fix port conflicts by configuring your project to use different ports.
- Fix port conflicts by stopping the competing application.
Method 1: Stop the conflicting application¶
lando poweroff for Lando, or
fin system stop for Docksal, or stop MAMP using GUI interface or
Method 2: Fix port conflicts by configuring your project to use different ports¶
To configure a project to use non-conflicting ports, edit the project’s
.ddev/config.yaml to add entries like
router_http_port: 8000 and
router_https_port: 8443 depending on your needs. Then, use
ddev start again.
For example, if there was a port conflict with a local Apache HTTP on port 80, add the following to the
ddev start. This changes the project’s HTTP URL to
http://yoursite.ddev.site:8080 and the HTTPS URL to
If the conflict is over port 8025, it’s normally a conflict over the default port for MailHog. You can add the following to
If the conflict is over port 8036, it’s normally about phpMyAdmin, and you can add the following to
Method 3: Fix port conflicts by stopping the competing application¶
Alternatively, stop the other application.
Probably the most common conflicting application is Apache running locally. It can often be stopped gracefully (but temporarily) with:
Common tools that use port 80 and port 443:
Here are some of the other common processes that could be using ports 80/443 and methods to stop them.
- MAMP (macOS): Stop MAMP.
- Apache: Temporarily stop with
sudo apachectl stop, permanent stop depends on your environment.
- nginx (macOS Homebrew):
sudo brew services stop nginxor
sudo launchctl stop homebrew.mxcl.nginx.
- nginx (Ubuntu):
sudo service nginx stop.
- Apache (many environments, often named “httpd”):
sudo apachectl stopor on Ubuntu
sudo service apache2 stop.
- VPNKit (macOS): You likely have a Docker container bound to port 80. Do you have containers up for Lando or another Docker-based development environment? If so, stop the other environment.
- Lando: If you’ve previously used Lando, try running
- IIS on Windows (can affect WSL2). You’ll have to disable it in the Windows settings.
To dig deeper, you can use a number of tools to find out what process is listening.
On macOS and Linux, try the
lsof tool on ports 80 or 443 or whatever port you’re having trouble with:
On Windows CMD, use sysinternals tcpview or try using
tasklist to find the process ID:
The resulting output displays which command is running and its PID. Choose the appropriate method to stop the other server.
You may also be able to find what’s using a port using
curl. On Linux, macOS, or in Git Bash on Windows,
curl -I localhost or
curl -I -k https://localhost:443. The result may give you a hint about which application is at fault.
We welcome your suggestions based on other issues you’ve run into and your troubleshooting technique.
Debugging Port Issues on WSL2¶
On WSL2 it’s harder to debug this because the port may be occupied either on the traditional Windows side, or within your WSL2 distro. This means you may have to debug it in both places, perhaps using both the Windows techniques shown above and the Linux techniques shown above. The ports are shared between Windows and WSL2, so they can be broken on either side.
Database Container Fails to Start¶
ddev logs -s db to see what’s wrong.
The most common cause of the database container not coming up is changing the database type or version in the project configuration, so the database server daemon is unable to start using an existing configuration for a different type or version.
To solve this:
- Change the configuration in
.ddev/config.yamlback to the original configuration.
- Export the database with
- Delete the project with
ddev delete, or stop the project and remove the database volume using
docker volume rm <project>-mariadbor
docker volume rm <project>-postgres.
.ddev/config.yamlto use the new database type or version.
- Start the project and import the database from your export.
“web service unhealthy” or “web service starting” or Exited¶
ddev logs to see what’s wrong.
The most common cause of the web container being unhealthy is a user-defined
.ddev/apache/apache-site.conf. Please rename these to
<xxx_site.conf> during testing. To figure out what’s wrong with it after you’ve identified that as the problem, use
ddev logs and review the error.
.ddev/apache/apache-site.conf take effect only when you do a
ddev restart or the equivalent.
No Input File Specified (404) or Forbidden (403)¶
If you get a 404 with “No input file specified” (nginx) or a 403 with “Forbidden” (Apache) when you visit your project, it usually means that no
index.html is being found in the docroot. This can result from:
- Misconfigured docroot: If the docroot isn’t where the web server thinks it is, then the web server won’t find
index.php. Look at your
.ddev/config.yamlto verify it has a docroot containing
index.php. It should be a relative path.
index.php: There may not be an
index.htmlin your project.
ddev start Fails and Logs Contain "failed (28: No space left on device)" - Docker File Space¶
ddev start fails, it’s most often because the
db container fails to start. In this case, the error message from
ddev start says something like “Failed to start
ddev logs -s db to find out what happened.
If you see any variant of “no space left on device” in the logs when using Docker Desktop, it means you have to increase or clean up Docker’s file space. Increase the “Disk image size” setting under “Resources” in Docker’s Preferences:
If you see “no space left on device” on Linux, it most likely means your filesystem is full.
ddev start Fails with "container failed to become ready"¶
A container fails to become ready when its health check is failing. This can happen to any of the containers, and you can usually find the issue with a
docker inspect command.
You may need to install jq for these examples (
brew install jq), or just remove the
| jq from the command and read the raw JSON output.
Don’t forget to check logs using
ddev logs for the
web container, and
ddev logs -s db for the
docker logs ddev-router and
docker logs ddev-ssh-agent.
ddev debug router-nginx-config to print the nginx configuration of the currently running
ddev start Fails with "Failed to start [project name]: No such container: ddev-router"¶
Deleting the images and re-pulling them generally solves this problem.
Try running the following commands from the host machine:
You should then be able to start your DDEV machine.
Trouble Building Dockerfiles¶
.ddev/web-build/Dockerfile capability in DDEV is wonderful, but it can be hard to figure out what to put in there.
The best approach for any significant Dockerfile is to
ddev ssh and
sudo -s and then one at a time, do the things that you plan to do with a
RUN command in the Dockerfile.
For example, if your Dockerfile were
You could test it with
sudo -s, and then
npm install --global forever.
The error messages you get will be more informative than messages that come when the Dockerfile is processed.
You can also see the full Docker build using
~/.ddev/bin/docker-compose -f .ddev/.ddev-docker-compose-full.yaml build --no-cache --progress=plain.
DDEV Starts but Browser Can’t Access URL¶
You may see one of two messages in your browser:
- [url] server IP address could not be found
- We can’t connect to the server at [url]
Most people use
*.ddev.site URLs, which work great most of the time but require internet access.
*.ddev.site is a wildcard DNS entry that always returns the IP address 127.0.0.1 (localhost). If you’re not connected to the internet, however, or if various other name resolution issues fail, this name resolution won’t work.
While DDEV can create a web server and a Docker network infrastructure for a project, it doesn’t have control of your computer’s name resolution, so its backup technique to make a hostname resolvable by the browser is to add an entry to the hosts file (
/etc/hosts on Linux and macOS,
C:\Windows\system32\drivers\etc\hosts on traditional Windows).
- If you’re not connected to the internet, your browser will not be able to look up
*.ddev.sitehostnames. DDEV works fine offline, but for your browser to look up names they’ll have to be resolved in a different way.
- DDEV assumes that hostnames can be resolved within 3 seconds. That assumption is not valid on all networks or computers, so you can increase the amount of time it waits for resolution. Increasing to 5 seconds, for example:
ddev config global --internet-detection-timeout-ms=5000.
- If DDEV detects that it can’t look up one of the hostnames assigned to your project for that or other reasons, it will try to add that to the hosts file on your computer, which requires administrative privileges (sudo or Windows UAC).
- This technique may not work on Windows WSL2, see below.
- Only 10 hosts are valid per line on some versions of traditional Windows, see below; beyond that hostnames are ignored.
DNS Rebinding Prohibited¶
You may see one of several messages:
- Cannot resolve
- unknown host
- No address associated with hostname
Some DNS servers prevent the use of DNS records that resolve to
localhost (127.0.0.1) because in uncontrolled environments this may be used as a form of attack called DNS Rebinding. Since
*.ddev.site resolves to 127.0.0.1, they may refuse to resolve, and your browser may be unable to look up a hostname, and give you messages like “
You verify this is your problem by running
ping dkkd.ddev.site. If you get “No address associated with hostname” or something of that type, your computer is unable to look up
In this case, you can take any one of the following approaches:
- Reconfigure your router to allow DNS Rebinding. Many Fritzbox routers have added default DNS Rebinding disallowal, and they can be reconfigured to allow it. See issue. If you have the local dnsmasq DNS server it may also be configured to disallow DNS rebinding, but it’s a simple change to a configuration directive to allow it.
- Most computers can use most relaxed DNS resolution if they are not on corporate intranets that have non-internet DNS. So for example, the computer can be set to use 126.96.36.199 (Google) or 188.8.131.52 (Cloudflare) for DNS name resolution.
- If you have control of the router, you can usually change its DHCP settings to choose a public, relaxed DNS server as in #2.
- You can live with DDEV trying to edit the
/etc/hostsfile, which it only has to do when a new name is added to a project.
Windows Hosts File May Be Limited to 10 Hosts Per Line¶
On some Windows systems, there is a limit to the number of hosts that can be placed in one line. But since all DDEV hosts are typically on the same IP address (typically 127.0.0.1, localhost), they can add up. As soon as you have more than 10 entries there, your browser won’t be able to resolve the addresses beyond the 10th entry.
There are two workarounds for this problem:
ddev stop --alland
sudo ddev hostname --remove-inactiveto prune the number of hosts. When you start a project, its hostname(s) will be re-added again.
- Manually edit the hosts file (typically
C:\Windows\System32\drivers\etc\hosts) and put some of your hosts on a separate line in the file.
Windows WSL2 Network Issues¶
If you’re using a browser on Windows, accessing a project in WSL2, you can end up with confusing results when your project is listening on a port inside WSL2 while a Windows process is listening on that same port. The way to sort this out is to stop your project inside WSL2, verify that nothing is listening on the port there, and then study the port on the Windows side by visiting it with a browser or using other tools as described above.
Limitations on Symbolic Links (symlinks)¶
Symbolic links are widely used but have specific limitations in many environments, not just in DDEV. Here are some of the ways those may affect you:
- Crossing mount boundaries: Symlinks may not generally cross between network mounts. In other words, if you have a relative symlink in the root of your project directory on the host that points to
../somefile.txt, that symlink will not be valid inside the container where
../is a completely different filesystem (and is typically not mounted).
- Symlinks to absolute paths: If you have an absolute symlink to something like
/Users/xxx/somefile.txton the host, it will not be resolvable inside the container because
/Usersis not mounted there. Some tools, especially on Magento 2, may create symlinks to rooted paths, with targets like
/var/www/html/path/to/something. These basically can’t make it to the host and may create errors.
- Windows restrictions on symlinks: Inside the Docker container on Windows, you may not be able to create a symlink that goes outside the container.
- Mutagen restrictions on Windows symlinks: On macOS and Linux (including WSL2) the default
posix-rawtype of symlink handling. (See mutagen docs). This basically means that any symlink created will try to sync, regardless of whether it’s valid in the other environment. However, Mutagen does not support posix-raw on traditional Windows, so DDEV uses the
portablesymlink mode. So on Windows with Mutagen, symlinks have to be strictly limited to relative links that are inside the Mutagen section of the project.
Delete and Re-Download Docker Images¶
In a few unusual cases, the actual downloaded Docker images can somehow get corrupted. Deleting the images will force them to be re-downloaded or rebuilt. This does no harm, as everything is just rebuilt, but a
ddev start will take longer while it downloads needed resources: