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https://github.com/jeremyxu2010/cni-ipam-etcd

IPAM CNI plugin with etcd backend. Plugin could be used for IP allocation in container networks.
https://github.com/jeremyxu2010/cni-ipam-etcd

Last synced: 2 months ago
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IPAM CNI plugin with etcd backend. Plugin could be used for IP allocation in container networks.

Host: GitHub
URL: https://github.com/jeremyxu2010/cni-ipam-etcd
Owner: jeremyxu2010
Created: 2019-07-01T09:55:05.000Z (almost 5 years ago)
Default Branch: master
Last Pushed: 2023-03-06T23:19:31.000Z (over 1 year ago)
Last Synced: 2024-01-20T21:51:05.251Z (5 months ago)
Language: Go
Size: 27.3 KB
Stars: 39
Watchers: 1
Forks: 32
Open Issues: 3
Metadata Files:
- Readme: README.md

Lists

awesome-cloud-native - cni-ipam-etcd - IPAM CNI plugin with etcd backend. (NetWork)

README

# etcd IP address management plugin

Inspired by [host-local](https://github.com/containernetworking/plugins/tree/master/plugins/ipam/host-local) and [cni-ipam-consul](https://github.com/logingood/cni-ipam-consul) cni plugins. The etcd IPAM allocates IPv4 and IPv6 addresses out of a specified address range. Optionally,
it can include a DNS configuration from a `resolv.conf` file on the host.

## Overview

etcd IPAM plugin allocates ip addresses out of a set of address ranges.
It stores the state locally on the remote etcd, therefore ensuring uniqueness of IP addresses in a cluster.

The allocator can allocate multiple ranges, and supports sets of multiple (disjoint)
subnets. The allocation strategy is loosely round-robin within each range set.

## Example configurations

Note that the key `ranges` is a list of range sets. That is to say, the length
of the top-level array is the number of addresses returned. The second-level
array is a set of subnets to use as a pool of possible addresses.

This example configuration returns 2 IP addresses.

```json
{
"ipam": {
"name": "myetcd-ipam",
"type": "etcd",
"etcdConfig": {
"etcdURL": "https://127.0.0.1:2379",
"etcdCertFile": "/tmp/etcd.pem",
"etcdKeyFile": "/tmp/etcd-key.pem",
"etcdTrustedCAFileFile": "/tmp/ca.pem"
},
"ranges": [
[
{
"subnet": "10.10.0.0/16",
"rangeStart": "10.10.1.20",
"rangeEnd": "10.10.3.50",
"gateway": "10.10.0.254"
},
{
"subnet": "172.16.5.0/24"
}
],
[
{
"subnet": "3ffe:ffff:0:01ff::/64",
"rangeStart": "3ffe:ffff:0:01ff::0010",
"rangeEnd": "3ffe:ffff:0:01ff::0020"
}
]
],
"routes": [
{ "dst": "0.0.0.0/0" },
{ "dst": "192.168.0.0/16", "gw": "10.10.5.1" },
{ "dst": "3ffe:ffff:0:01ff::1/64" }
]
}
}
```

Previous versions of the `etcd` allocator did not support the `ranges`
property, and instead expected a single range on the top level. This is
deprecated but still supported.
```json
{
"ipam": {
"name": "myetcd-ipam",
"type": "etcd",
"etcdConfig": {
"etcdURL": "https://127.0.0.1:2379",
"etcdCertFile": "/tmp/etcd.pem",
"etcdKeyFile": "/tmp/etcd-key.pem",
"etcdTrustedCAFileFile": "/tmp/ca.pem"
},
"subnet": "3ffe:ffff:0:01ff::/64",
"rangeStart": "3ffe:ffff:0:01ff::0010",
"rangeEnd": "3ffe:ffff:0:01ff::0020",
"routes": [
{ "dst": "3ffe:ffff:0:01ff::1/64" }
],
"resolvConf": "/etc/resolv.conf"
}
}
```

We can test it out on the command-line:

```bash
# Test add operation
$ echo '{ "cniVersion": "0.3.1", "name": "examplenet", "ipam": { "name": "myetcd-ipam", "type": "etcd", "etcdConfig": { "etcdURL": "https://127.0.0.1:2379", "etcdCertFile": "etcdKeyFile": "/tmp/etcd-key.pem", "etcdTrustedCAFileFile": "/tmp/ca.pem" }, "ranges": [ [{"subnet": "203.0.113.0/24"}], [{"subnet": "2001:db8:1::/64"}]] } }' | CNI_COMMAND=ADD CNI_CONTAINERID=example CNI_NETNS=/dev/null CNI_IFNAME=dummy0 CNI_PATH=. ./etcd

# Test del operation
$ echo '{ "cniVersion": "0.3.1", "name": "examplenet", "ipam": { "name": "myetcd-ipam", "type": "etcd", "etcdConfig": { "etcdURL": "https://127.0.0.1:2379", "etcdCertFile": "etcdKeyFile": "/tmp/etcd-key.pem", "etcdTrustedCAFileFile": "/tmp/ca.pem" }, "ranges": [ [{"subnet": "203.0.113.0/24"}], [{"subnet": "2001:db8:1::/64"}]] } }' | CNI_COMMAND=DEL CNI_CONTAINERID=example CNI_NETNS=/dev/null CNI_IFNAME=dummy0 CNI_PATH=. ./etcd

```

```json
{
"ips": [
{
"version": "4",
"address": "203.0.113.2/24",
"gateway": "203.0.113.1"
},
{
"version": "6",
"address": "2001:db8:1::2/64",
"gateway": "2001:db8:1::1"
}
],
"dns": {}
}
```

## Network configuration reference

* `type` (string, required): "etcd".
* `routes` (string, optional): list of routes to add to the container namespace. Each route is a dictionary with "dst" and optional "gw" fields. If "gw" is omitted, value of "gateway" will be used.
* `resolvConf` (string, optional): Path to a `resolv.conf` on the host to parse and return as the DNS configuration
* `ranges`, (array, required, nonempty) an array of arrays of range objects:
* `subnet` (string, required): CIDR block to allocate out of.
* `rangeStart` (string, optional): IP inside of "subnet" from which to start allocating addresses. Defaults to ".2" IP inside of the "subnet" block.
* `rangeEnd` (string, optional): IP inside of "subnet" with which to end allocating addresses. Defaults to ".254" IP inside of the "subnet" block for ipv4, ".255" for IPv6
* `gateway` (string, optional): IP inside of "subnet" to designate as the gateway. Defaults to ".1" IP inside of the "subnet" block.
* `etcdConfig`, an object of etcd address info
* `etcdURL` (string, required): The URL of etcd
* `etcdCertFile` (string, required): The cert file of etcd
* `etcdKeyFile` (string, required): The key file of etcd
* `etcdTrustedCAFileFile` (string, required): The ca file of etcd

Older versions of the `etcd` plugin did not support the `ranges` array. Instead,
all the properties in the `range` object were top-level. This is still supported but deprecated.

## Supported arguments
The following [CNI_ARGS](https://github.com/containernetworking/cni/blob/master/SPEC.md#parameters) are supported:

* `ip`: request a specific IP address from a subnet.

The following [args conventions](https://github.com/containernetworking/cni/blob/master/CONVENTIONS.md) are supported:

* `ips` (array of strings): A list of custom IPs to attempt to allocate

The following [Capability Args](https://github.com/containernetworking/cni/blob/master/CONVENTIONS.md) are supported:

* `ipRanges`: The exact same as the `ranges` array - a list of address pools

### Custom IP allocation
For every requested custom IP, the `etcd` allocator will request that IP
if it falls within one of the `range` objects. Thus it is possible to specify
multiple custom IPs and multiple ranges.

If any requested IPs cannot be reserved, either because they are already in use
or are not part of a specified range, the plugin will return an error.

## KVs

The kvs written by this cni plugin can query by the script:

```bash
$ ETCDCTL_API=3 etcdctl --endpoints='127.0.0.1:2379' --key=/tmp/etcd-key.pem --cert=/tmp/etcd.pem --cacert=/tmp/ca.pem get --prefix '/etcd-cni/networks/'
```