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Version: v2.0.4

Docker

Use dfget daemon as HTTP proxy for docker daemon

Currently, docker doesn't support private registries with registry-mirrors, in order to do so, we need to use HTTP proxy for docker daemon.

Quick Start​

Step 1: Generate CA certificate for HTTP proxy​

Generate a CA certificate private key.

openssl genrsa -out ca.key 2048

Open openssl config file openssl.conf. Note set basicConstraints to true, that you can modify the values.

[ req ]
#default_bits = 2048
#default_md = sha256
#default_keyfile = privkey.pem
distinguished_name = req_distinguished_name
attributes = req_attributes
extensions               = v3_ca
req_extensions           = v3_ca
[ req_distinguished_name ]
countryName = Country Name (2 letter code)
countryName_min = 2
countryName_max = 2
stateOrProvinceName = State or Province Name (full name)
localityName = Locality Name (eg, city)
0.organizationName = Organization Name (eg, company)
organizationalUnitName = Organizational Unit Name (eg, section)
commonName = Common Name (eg, fully qualified host name)
commonName_max = 64
emailAddress = Email Address
emailAddress_max = 64
[ req_attributes ]
challengePassword = A challenge password
challengePassword_min = 4
challengePassword_max = 20
[ v3_ca ]
basicConstraints         = CA:TRUE

Generate the CA certificate.

openssl req -new -key ca.key -nodes -out ca.csr -config openssl.conf
openssl x509 -req -days 36500 -extfile openssl.conf \
    -extensions v3_ca -in ca.csr -signkey ca.key -out ca.crt

Step 2: Configure dfget daemon​

To use dfget daemon as HTTP proxy, first you need to append a proxy rule in /etc/dragonfly/dfget.yaml, This will proxy your.private.registry's requests for image layers:

proxy:
  security:
    insecure: true
  tcpListen:
    listen: 0.0.0.0
    port: 65001
  proxies:
    - regx: blobs/sha256.*
  hijackHTTPS:
    # CA certificate's path used to hijack https requests
    cert: ca.crt
    key: ca.key
    hosts:
      - regx: your.private.registry

Step 3: Configure Docker daemon​

Add your private registry to insecure-registries in /etc/docker/daemon.json, in order to ignore the certificate error:

{
  "insecure-registries": ["your.private.registry"]
}

Step 4: Configure Docker daemon​

Set dfdaemon as HTTP_PROXY and HTTPS_PROXY for docker daemon in /etc/systemd/system/docker.service.d/http-proxy.conf:

[Service]
Environment="HTTP_PROXY=http://127.0.0.1:65001"
Environment="HTTPS_PROXY=http://127.0.0.1:65001"

Step 5: Pull images with proxy​

Through the above steps, we can start to validate if Dragonfly works as expected.

And you can pull the image as usual, for example:

docker pull your.private.registry/namespace/image:latest

Custom assets​

Registry uses a self-signed certificate​

If your registry uses a self-signed certificate, you can either choose to ignore the certificate error with:

proxy:
  security:
    insecure: true
  tcpListen:
    listen: 0.0.0.0
    port: 65001
  proxies:
    - regx: blobs/sha256.*
  hijackHTTPS:
    # CA certificate's path used to hijack https requests
    cert: ca.crt
    key: ca.key
    hosts:
      - regx: your.private.registry
        insecure: true

Or provide a certificate with:

proxy:
  security:
    insecure: true
  tcpListen:
    listen: 0.0.0.0
    port: 65001
  proxies:
    - regx: blobs/sha256.*
  hijackHTTPS:
    # CA certificate's path used to hijack https requests
    cert: ca.crt
    key: ca.key
    hosts:
      - regx: your.private.registry
        certs: ['server.crt']

You can get the certificate of your server with:

openssl x509 -in <(openssl s_client -showcerts \
    -servername your.domain.com -connect your.domain.com:443 -prexit 2>/dev/null)