90 lines
3.7 KiB
Markdown
90 lines
3.7 KiB
Markdown
<!--[metadata]>
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+++
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title = "Testing an insecure registry"
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description = "Deploying a Registry in an insecure fashion"
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keywords = ["registry, on-prem, images, tags, repository, distribution, insecure"]
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+++
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<![end-metadata]-->
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# Insecure Registry
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While it's highly recommended to secure your registry using a TLS certificate issued by a known CA, you may alternatively decide to use self-signed 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 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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1. edit the file `/etc/default/docker` so that there is a line that reads: `DOCKER_OPTS="--insecure-registry myregistrydomain.com:5000"` (or add that to existing `DOCKER_OPTS`)
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2. restart your Docker daemon: on ubuntu, this is usually `service docker stop && service docker start`
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**Pros:**
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- relatively easy to configure
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**Cons:**
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- this is **very** insecure: you are basically exposing yourself to trivial MITM, and this solution should only be used for isolated testing or in a tightly controlled, air-gapped environment
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- you have to configure every docker daemon 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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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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Be sure to use the name `myregistrydomain.com` as a CN.
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Use the result to [start your registry with TLS enabled](https://github.com/docker/distribution/blob/master/docs/deploying.md#get-a-certificate)
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Then you have to instruct every docker daemon to trust that certificate. This is done by copying the `domain.crt` file to `/etc/docker/certs.d/myregistrydomain.com:5000/ca.crt`.
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Don't forget to restart docker after doing so.
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**Pros:**
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- more secure than the insecure registry solution
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**Cons:**
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- you have to configure every docker daemon that wants to access your registry
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## Failing...
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Failing to configure docker and trying to pull from a registry that is not using TLS will result 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.
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Usually, on Ubuntu this is done with:
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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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... and on Red Hat (and its derivatives) with:
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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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... On some distributions, e.g. Oracle Linux 6, the Shared System Certificates feature needs to be manually enabled:
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update-ca-trust enable
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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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