split README into registry-specific sections; add GitLab example (fixes #27 thanks @bephinix); some rewording

pull/51/head
Ricardo Pardini 2020-10-06 11:06:42 +02:00
parent a2c0afcbc4
commit f2254685f8
1 changed files with 61 additions and 19 deletions

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@ -2,14 +2,15 @@
### TL,DR
A caching proxy for Docker; allows centralised management of registries and their authentication; caches images from *any* registry.
A caching proxy for Docker; allows centralised management of (multiple) registries and their authentication; caches images from *any* registry.
### What?
Created as an evolution and simplification of [docker-caching-proxy-multiple-private](https://github.com/rpardini/docker-caching-proxy-multiple-private)
using the `HTTPS_PROXY` mechanism and injected CA root certificates instead of `/etc/hosts` hacks and `--insecure-registry`
Essentially, it's a [man in the middle](https://en.wikipedia.org/wiki/Man-in-the-middle_attack): an intercepting proxy based on `nginx`, to which all docker traffic is directed using the `HTTPS_PROXY` mechanism and injected CA root certificates.
Main feature is Docker layer/image caching, even from S3, Google Storage, etc. As a bonus it allows for centralized management of Docker registry credentials.
The main feature is Docker layer/image caching, including layers served from S3, Google Storage, etc.
As a bonus it allows for centralized management of Docker registry credentials, which can in itself be the main feature, eg in Kubernetes environments.
You configure the Docker clients (_err... Kubernetes Nodes?_) once, and then all configuration is done on the proxy --
for this to work it requires inserting a root CA certificate into system trusted root certs.
@ -17,24 +18,26 @@ for this to work it requires inserting a root CA certificate into system trusted
### master is unstable/beta
- `master` (and `:latest` Docker tag) is unstable
- Currently stable version is `0.3.0`, see [0.3.0 tag on Github](https://github.com/rpardini/docker-registry-proxy/tree/0.3.0)
- Currently, stable version is `0.3.0`, see [0.3.0 tag on Github](https://github.com/rpardini/docker-registry-proxy/tree/0.3.0)
### Usage
- Run the proxy on a host close to the Docker clients
- Run the proxy on a host close (network-wise: high bandwidth, same-VPC, etc) to the Docker clients
- Expose port 3128 to the network
- Map volume `/docker_mirror_cache` for up to 32gb of cached images from all registries
- Map volume `/ca`, the proxy will store the CA certificate here across restarts
- Map volume `/docker_mirror_cache` for up to `CACHE_MAX_SIZE` (32gb by default) of cached images across all cached registries
- Map volume `/ca`, the proxy will store the CA certificate here across restarts. **Important** this is security sensitive.
- Env `CACHE_MAX_SIZE` (default `32g`): set the max size to be used for caching local Docker image layers. Use [Nginx sizes](http://nginx.org/en/docs/syntax.html).
- Env `REGISTRIES`: space separated list of registries to cache; no need to include Docker Hub, its already there.
- Env `AUTH_REGISTRIES`: space separated list of `hostname:username:password` authentication info.
- `hostname`s listed here should be listed in the REGISTRIES environment as well, so they can be intercepted.
- For Docker Hub authentication, `hostname` should be `auth.docker.io`, username should NOT be an email, use the regular username.
- For regular registry auth (HTTP Basic), `hostname` here should be the same... unless your registry uses a different auth server. This should work for quay.io also, but I have no way to test.
- Env `AUTH_REGISTRIES_DELIMITER` to change the separator between authentication info. By default, a space: "` `". If you use keys that contain spaces (as with Google Cloud Registry), you should update this variable, e.g. setting it to `AUTH_REGISTRIES_DELIMITER=";;;"`. In that case, `AUTH_REGISTRIES` could contain something like `registry1.com:user1:pass1;;;registry2.com:user2:pass2`.
- Env `AUTH_REGISTRY_DELIMITER` to change the separator between authentication info *parts*. By default, a colon: "`:`". If you use keys that contain single colons, you should update this variable, e.g. setting it to `AUTH_REGISTRIES_DELIMITER=":::"`. In that case, `AUTH_REGISTRIES` could contain something like `registry1.com:::user1:::pass1 registry2.com:::user2:::pass2`.
- For Google Container Registry (GCR), username should be `_json_key` and the password should be the contents of the service account JSON. Check out [GCR docs](https://cloud.google.com/container-registry/docs/advanced-authentication#json_key_file). The service account key is in JSON format, it contains spaces ("` `") and colons ("`:`"). To be able to use GCR you should set `AUTH_REGISTRIES_DELIMITER` to something different than space (e.g. `AUTH_REGISTRIES_DELIMITER=";;;"`) and `AUTH_REGISTRY_DELIMITER` to something different than a single colon (e.g. `AUTH_REGISTRY_DELIMITER=":::"`).
- Env `AUTH_REGISTRIES_DELIMITER` to change the separator between authentication info. By default, a space: "` `". If you use keys that contain spaces (as with Google Cloud Registry), you should update this variable, e.g. setting it to `AUTH_REGISTRIES_DELIMITER=";;;"`. In that case, `AUTH_REGISTRIES` could contain something like `registry1.com:user1:pass1;;;registry2.com:user2:pass2`.
- Env `AUTH_REGISTRY_DELIMITER` to change the separator between authentication info *parts*. By default, a colon: "`:`". If you use keys that contain single colons, you should update this variable, e.g. setting it to `AUTH_REGISTRIES_DELIMITER=":::"`. In that case, `AUTH_REGISTRIES` could contain something like `registry1.com:::user1:::pass1 registry2.com:::user2:::pass2`.
#### DockerHub specifics
For Docker Hub authentication:
- `hostname` should be `auth.docker.io`
- `username` should NOT be an email, use the regular username
```bash
docker run --rm --name docker_registry_proxy -it \
@ -46,6 +49,43 @@ docker run --rm --name docker_registry_proxy -it \
rpardini/docker-registry-proxy:0.3.0
```
#### Simple registries (HTTP Basic auth)
For regular registry auth (HTTP Basic), the `hostname` should be the registry itself... unless your registry uses a different auth server.
See the example above for DockerHub, adapt the `your.own.registry` parts (in both ENVs).
This should work for quay.io also, but I have no way to test.
#### GitLab specifics
GitLab may use a different/separate domain to handle the authentication procedure.
Just like DockerHub uses `auth.docker.io`, GitLab uses its primary (git) domain for the authentication.
If you run GitLab on `git.example.com` and its registry on `reg.example.com`, you need to include both in `REGISTRIES` and use the primary domain for `AUTH_REGISTRIES`.
For GitLab.com itself the authentication domain should be `gitlab.com`.
```bash
docker run --rm --name docker_registry_proxy -it \
-p 0.0.0.0:3128:3128 \
-v $(pwd)/docker_mirror_cache:/docker_mirror_cache \
-v $(pwd)/docker_mirror_certs:/ca \
-e REGISTRIES="reg.example.com git.example.com" \
-e AUTH_REGISTRIES="git.example.com:USER:PASSWORD" \
rpardini/docker-registry-proxy:0.3.0
```
#### Google Container Registry (GCR) specifics
For Google Container Registry (GCR), username should be `_json_key` and the password should be the contents of the service account JSON.
Check out [GCR docs](https://cloud.google.com/container-registry/docs/advanced-authentication#json_key_file).
The service account key is in JSON format, it contains spaces ("` `") and colons ("`:`").
To be able to use GCR you should set `AUTH_REGISTRIES_DELIMITER` to something different than space (e.g. `AUTH_REGISTRIES_DELIMITER=";;;"`) and `AUTH_REGISTRY_DELIMITER` to something different than a single colon (e.g. `AUTH_REGISTRY_DELIMITER=":::"`).
Example with GCR using credentials from a service account from a key file `servicekey.json`:
```bash
@ -60,9 +100,9 @@ docker run --rm --name docker_registry_proxy -it \
rpardini/docker-registry-proxy:0.3.0
```
Let's say you did this on host `192.168.66.72`, you can then `curl http://192.168.66.72:3128/ca.crt` and get the proxy CA certificate.
### Configuring the Docker clients / Kubernetes nodes
#### Configuring the Docker clients / Kubernetes nodes
Let's say you setup the proxy on host `192.168.66.72`, you can then `curl http://192.168.66.72:3128/ca.crt` and get the proxy CA certificate.
On each Docker host that is to use the cache:
@ -108,9 +148,11 @@ Test your own registry caching and authentication the same way; you don't need `
### Gotchas
- If you authenticate to a private registry and pull through the proxy, those images will be served to any client that can reach the proxy, even without authentication. *beware*
- Repeat, this will make your private images very public if you're not careful.
- Repeat, **this will make your private images very public if you're not careful**.
- **Currently you cannot push images while using the proxy** which is a shame. PRs welcome.
- Setting this on Linux is relatively easy. On Mac and Windows the CA-certificate part will be very different but should work in principle.
- Setting this on Linux is relatively easy.
- On Mac and Windows the CA-certificate part will be very different but should work in principle.
- Please send PRs with instructions for Windows and Mac if you succeed!
#### Why not use Docker's own registry, which has a mirror feature?
@ -133,6 +175,6 @@ Yeah. Docker Inc should do it. So should NPM, Inc. Wonder why they don't. 😼
- Allow using multiple credentials for DockerHub; this is possible since the `/token` request includes the wanted repo as a query string parameter.
- Test and make auth work with quay.io, unfortunately I don't have access to it (_hint, hint, quay_)
- Hide the mitmproxy building code under a Docker build ARG.
- Hide the mitmproxy building code under a Docker build ARG. [DONE]
- I hope that in the future this can also be used as a "Developer Office" proxy, where many developers on a fast local network
share a proxy for bandwidth and speed savings; work is ongoing in this direction.