If you are using the Omnibus GitLab built in [Let's Encrypt integration](https://docs.gitlab.com/omnibus/settings/ssl.html#lets-encrypt-integration), as of GitLab 12.5, the Container Registry will be automatically enabled on port 5050 of the default domain.
If you would like to use a separate domain, all you have to do is configure the domain name under which the Container
| `enabled` | `true` or `false`. Enables the Registry in GitLab. By default this is `false`. |
| `host` | The host URL under which the Registry will run and the users will be able to use. |
| `port` | The port under which the external Registry domain will listen on. |
| `api_url` | The internal API URL under which the Registry is exposed to. It defaults to `http://localhost:5000`. |
| `key` | The private key location that is a pair of Registry's `rootcertbundle`. Read the [token auth configuration documentation](https://docs.docker.com/registry/configuration/#token). |
| `path` | This should be the same directory like specified in Registry's `rootdirectory`. Read the [storage configuration documentation](https://docs.docker.com/registry/configuration/#storage). This path needs to be readable by the GitLab user, the web-server user and the Registry user. Read more in [#container-registry-storage-path](#container-registry-storage-path). |
| `issuer` | This should be the same value as configured in Registry's `issuer`. Read the [token auth configuration documentation](https://docs.docker.com/registry/configuration/#token). |
NOTE: **Note:**
A Registry init file is not shipped with GitLab if you install it from source.
Hence, [restarting GitLab](../restart_gitlab.md#installations-from-source) will not restart the Registry should
you modify its settings. Read the upstream documentation on how to achieve that.
At the **absolute** minimum, make sure your [Registry configuration](https://docs.docker.com/registry/configuration/#auth)
has `container_registry` as the service and `https://gitlab.example.com/jwt/auth`
as the realm:
```yaml
auth:
token:
realm: https://gitlab.example.com/jwt/auth
service: container_registry
issuer: gitlab-issuer
rootcertbundle: /root/certs/certbundle
```
CAUTION: **Caution:**
If `auth` is not set up, users will be able to pull docker images without authentication.
## Container Registry domain configuration
There are two ways you can configure the Registry's external domain. Either:
- [Use the existing GitLab domain](#configure-container-registry-under-an-existing-gitlab-domain) where in that case
the Registry will have to listen on a port and reuse GitLab's TLS certificate,
- [Use a completely separate domain](#configure-container-registry-under-its-own-domain) with a new TLS certificate
for that domain.
Since the container Registry requires a TLS certificate, in the end it all boils
down to how easy or pricey is to get a new one.
Please take this into consideration before configuring the Container Registry
for the first time.
### Configure Container Registry under an existing GitLab domain
If the Registry is configured to use the existing GitLab domain, you can
expose the Registry on a port so that you can reuse the existing GitLab TLS
certificate.
Assuming that the GitLab domain is `https://gitlab.example.com` and the port the
Registry is exposed to the outside world is `4567`, here is what you need to set
in `gitlab.rb` or `gitlab.yml` if you are using Omnibus GitLab or installed
GitLab from source respectively.
NOTE: **Note:**
Be careful to choose a port different than the one that Registry listens to (`5000` by default),
otherwise you will run into conflicts.
**Omnibus GitLab installations**
1. Your `/etc/gitlab/gitlab.rb` should contain the Registry URL as well as the
path to the existing TLS certificate and key used by GitLab:
In that case, you must use an address that resolves and is accessible outside GitLab server. The Docker client will continue to authenticate via GitLab but data transfer will be direct to and from the storage backend.
| s3 | Amazon Simple Storage Service. Be sure to configure your storage bucket with the correct [S3 Permission Scopes](https://docs.docker.com/registry/storage-drivers/s3/#s3-permission-scopes). |
### AWS S3 with the GitLab registry error when pushing large images
When using AWS S3 with the GitLab registry, an error may occur when pushing
large images. Look in the Registry log for the following error:
```
level=error msg="response completed with error" err.code=unknown err.detail="unexpected EOF" err.message="unknown error"
```
To resolve the error specify a `chunksize` value in the Registry configuration.
Start with a value between `25000000` (25MB) and `50000000` (50MB).
**For Omnibus installations**
1. Edit `/etc/gitlab/gitlab.rb`:
```ruby
registry['storage'] = {
's3' => {
'accesskey' => 'AKIAKIAKI',
'secretkey' => 'secret123',
'bucket' => 'gitlab-registry-bucket-AKIAKIAKI',
'chunksize' => 25000000
}
}
```
1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect.
**For installations from source**
1. Edit `config/gitlab.yml`:
```yaml
storage:
s3:
accesskey: 'AKIAKIAKI'
secretkey: 'secret123'
bucket: 'gitlab-registry-bucket-AKIAKIAKI'
chunksize: 25000000
```
1. Save the file and [restart GitLab](../restart_gitlab.md#installations-from-source) for the changes to take effect.
### Supporting older Docker clients
As of GitLab 11.9, we began shipping version 2.7.1 of the Docker container registry, which disables the schema1 manifest by default. If you are still using older Docker clients (1.9 or older), you may experience an error pushing images. See [omnibus-4145](https://gitlab.com/gitlab-org/omnibus-gitlab/issues/4145) for more details.
You can add a configuration option for backwards compatibility.
**For Omnibus installations**
1. Edit `/etc/gitlab/gitlab.rb`:
```ruby
registry['compatibility_schema1_enabled'] = true
```
1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect.
**For installations from source**
1. Edit the YML configuration file you created when you [deployed the registry](https://docs.docker.com/registry/deploying/). Add the following snippet:
```yaml
compatibility:
schema1:
enabled: true
```
1. Restart the registry for the changes to take affect.
### Docker connection error
A Docker connection error can occur when there are special characters in either the group,
project or branch name. Special characters can include:
- Leading underscore
- Trailing hyphen/dash
- Double hyphen/dash
To get around this, you can [change the group path](../../user/group/index.md#changing-a-groups-path),
[change the project path](../../user/project/settings/index.md#renaming-a-repository) or change the
branch name. Another option is to create a [push rule](../../push_rules/push_rules.html) to prevent
this at the instance level.
### Image push errors
When getting errors or "retrying" loops in an attempt to push an image but `docker login` works fine,
there is likely an issue with the headers forwarded to the registry by NGINX. The default recommended
NGINX configurations should handle this, but it might occur in custom setups where the SSL is
offloaded to a third party reverse proxy.
This problem was discussed in a [docker project issue](https://github.com/docker/distribution/issues/970)
and a simple solution would be to enable relative URLs in the Registry.
**For Omnibus installations**
1. Edit `/etc/gitlab/gitlab.rb`:
```ruby
registry['env'] = {
"REGISTRY_HTTP_RELATIVEURLS" => true
}
```
1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect.
**For installations from source**
1. Edit the YML configuration file you created when you [deployed the registry](https://docs.docker.com/registry/deploying/). Add the following snippet:
```yaml
http:
relativeurls: true
```
1. Save the file and [restart GitLab](../restart_gitlab.md#installations-from-source) for the changes to take effect.
### Enable the Registry debug server
The optional debug server can be enabled by setting the registry debug address
in your `gitlab.rb` configuration.
```ruby
registry['debug_addr'] = "localhost:5001"
```
After adding the setting, [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) to apply the change.
Use curl to request debug output from the debug server:
```bash
curl localhost:5001/debug/health
curl localhost:5001/debug/vars
```
### Advanced Troubleshooting
NOTE: **Note:**
The following section is only recommended for experts.
Sometimes it's not obvious what is wrong, and you may need to dive deeper into
the communication between the Docker client and the Registry to find out
what's wrong. We will use a concrete example in the past to illustrate how to
diagnose a problem with the S3 setup.
#### Unexpected 403 error during push
A user attempted to enable an S3-backed Registry. The `docker login` step went
fine. However, when pushing an image, the output showed:
```text
The push refers to a repository [s3-testing.myregistry.com:4567/root/docker-test/docker-image]
