Bryan Boreham
3cd1a17c23
Using the Ring CRDT and Weave gossip, provides an interface for the weave script to allocate IP addresses in `weave run`, `weave start` and `weave expose`. See docs/ipam.md for implementation details, and site/features.md for user-visible changes.
76 lines
2.0 KiB
Go
76 lines
2.0 KiB
Go
package ipam
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import (
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"fmt"
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"github.com/weaveworks/weave/ipam/address"
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"github.com/weaveworks/weave/router"
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)
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type claim struct {
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resultChan chan<- error
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hasBeenCancelled func() bool
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ident string
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addr address.Address
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}
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// Try returns true for success (or failure), false if we need to try again later
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func (c *claim) Try(alloc *Allocator) bool {
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if (c.hasBeenCancelled)() {
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c.Cancel()
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return true
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}
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if !alloc.ring.Contains(c.addr) {
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// Address not within our universe; assume user knows what they are doing
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alloc.infof("Ignored address %s claimed by %s - not in our universe\n", c.addr, c.ident)
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c.resultChan <- nil
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return true
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}
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// If our ring doesn't know, it must be empty. We will have initiated the
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// bootstrap of the ring, so wait until we find some owner for this
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// range (might be us).
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owner := alloc.ring.Owner(c.addr)
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if owner == router.UnknownPeerName {
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alloc.infof("Ring is empty; will try later.\n", c.addr, owner)
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return false
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}
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if owner != alloc.ourName {
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c.resultChan <- fmt.Errorf("Address %s is owned by other peer %s", c.addr.String(), owner)
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return true
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}
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// We are the owner, check we haven't given it to another container
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existingIdent := alloc.findOwner(c.addr)
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if existingIdent == c.ident {
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// same identifier is claiming same address; that's OK
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c.resultChan <- nil
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return true
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}
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if existingIdent == "" {
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err := alloc.space.Claim(c.addr)
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if err != nil {
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c.resultChan <- err
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return true
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}
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alloc.addOwned(c.ident, c.addr)
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c.resultChan <- nil
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return true
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}
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// Addr already owned by container on this machine
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c.resultChan <- fmt.Errorf("Claimed address %s is already owned by %s", c.addr.String(), existingIdent)
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return true
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}
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func (c *claim) Cancel() {
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c.resultChan <- fmt.Errorf("Operation cancelled.")
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}
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func (c *claim) String() string {
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return fmt.Sprintf("Claim %s -> %s", c.ident, c.addr.String())
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}
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func (c *claim) ForContainer(ident string) bool {
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return c.ident == ident
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}
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