114 lines
4.1 KiB
Markdown
114 lines
4.1 KiB
Markdown
---
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description: Deploying a Registry in an insecure fashion
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keywords:
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- registry, on-prem, images, tags, repository, distribution, insecure
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menu:
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main:
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parent: smn_registry_ref
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weight: 5
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title: Testing an insecure registry
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---
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# Insecure Registry
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While it's highly recommended to secure your registry using a TLS certificate
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issued by a known CA, you may alternatively decide to use self-signed
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certificates, or even use your registry over plain http.
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You have to understand the downsides in doing so, and the extra burden in
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configuration.
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## Deploying a plain HTTP registry
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> **Warning**: it's not possible to use an insecure registry with basic authentication.
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This basically tells Docker to entirely disregard security for your registry.
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While this is relatively easy to configure the daemon in this way, it is
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**very** insecure. It does expose your registry to trivial MITM. Only use this
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solution for isolated testing or in a tightly controlled, air-gapped
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environment.
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1. Open the `/etc/default/docker` file or `/etc/sysconfig/docker` for editing.
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Depending on your operating system, your Engine daemon start options.
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2. Edit (or add) the `DOCKER_OPTS` line and add the `--insecure-registry` flag.
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This flag takes the URL of your registry, for example.
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`DOCKER_OPTS="--insecure-registry myregistrydomain.com:5000"`
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3. Close and save the configuration file.
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4. Restart your Docker daemon
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The command you use to restart the daemon depends on your operating system.
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For example, on Ubuntu, this is usually the `service docker stop` and `service
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docker start` command.
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5. Repeat this configuration on every Engine host that wants to access your registry.
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## Using self-signed certificates
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> **Warning**: using this along with basic authentication requires to **also** trust the certificate into the OS cert store for some versions of docker (see below)
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This is more secure than the insecure registry solution. You must configure every docker daemon that wants to access your registry
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1. Generate your own certificate:
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mkdir -p certs && openssl req \
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-newkey rsa:4096 -nodes -sha256 -keyout certs/domain.key \
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-x509 -days 365 -out certs/domain.crt
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2. Be sure to use the name `myregistrydomain.com` as a CN.
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3. Use the result to [start your registry with TLS enabled](./deploying.md#get-a-certificate)
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4. Instruct every docker daemon to trust that certificate.
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This is done by copying the `domain.crt` file to `/etc/docker/certs.d/myregistrydomain.com:5000/ca.crt`.
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5. Don't forget to restart the Engine daemon.
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## Troubleshooting insecure registry
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This sections lists some common failures and how to recover from them.
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### Failing...
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Failing to configure the Engine daemon and trying to pull from a registry that is not using
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TLS will results in the following message:
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```
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FATA[0000] Error response from daemon: v1 ping attempt failed with error:
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Get https://myregistrydomain.com:5000/v1/_ping: tls: oversized record received with length 20527.
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If this private registry supports only HTTP or HTTPS with an unknown CA certificate,please add
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`--insecure-registry myregistrydomain.com:5000` to the daemon's arguments.
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In the case of HTTPS, if you have access to the registry's CA certificate, no need for the flag;
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simply place the CA certificate at /etc/docker/certs.d/myregistrydomain.com:5000/ca.crt
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```
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### Docker still complains about the certificate when using authentication?
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When using authentication, some versions of docker also require you to trust the certificate at the OS level. Usually, on Ubuntu this is done with:
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```bash
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$ cp certs/domain.crt /usr/local/share/ca-certificates/myregistrydomain.com.crt
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update-ca-certificates
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```
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... and on Red Hat (and its derivatives) with:
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```bash
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cp certs/domain.crt /etc/pki/ca-trust/source/anchors/myregistrydomain.com.crt
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update-ca-trust
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```
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... On some distributions, e.g. Oracle Linux 6, the Shared System Certificates feature needs to be manually enabled:
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```bash
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$ update-ca-trust enable
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```
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Now restart docker (`service docker stop && service docker start`, or any other way you use to restart docker).
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