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Do a soft reload of haproxy #212

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Do a soft reload of haproxy #212

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0555acf
Do a soft reload of haproxy
bnoon Feb 2, 2017
4c159a6
Log odd container states
bnoon Feb 2, 2017
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39 changes: 24 additions & 15 deletions ext/lb/haproxy/haproxy.go
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Original file line number Diff line number Diff line change
Expand Up @@ -64,25 +64,34 @@ func (p *HAProxyLoadBalancer) Template() string {
}

func (p *HAProxyLoadBalancer) Reload(proxyContainers []types.Container) error {
// drop SYN to allow for restarts
if err := p.dropSYN(); err != nil {
log().Warnf("error signaling clients to resend; you will notice dropped packets: %s", err)
}

// reload all interlock managed haproxy containers
for _, cnt := range proxyContainers {
// restart
log().Debugf("restarting proxy container: id=%s", cnt.ID)
d := time.Millisecond * 1000
if err := p.client.ContainerRestart(context.Background(), cnt.ID, &d); err != nil {
log().Errorf("error restarting container: id=%s err=%s", cnt.ID[:12], err)
// update the proxy container status
cInfo, err := p.client.ContainerInspect(context.Background(), cnt.ID)
if err != nil {
log().Errorf("unable to inspect proxy container: %s", err)
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@ehazlett ehazlett Feb 2, 2017

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This will fall through without a continue.

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@bnoon bnoon Feb 2, 2017

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The continue is there.

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@ehazlett ehazlett Feb 2, 2017

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Ah I didn't see it from the diff. 👍

continue
}
switch cInfo.State.Status {
case "exited":
log().Infof("restarting proxy container: id=%s", cnt.ID)
d := time.Millisecond * 1000
if err := p.client.ContainerRestart(context.Background(), cnt.ID, &d); err != nil {
log().Errorf("error restarting container: id=%s err=%s", cnt.ID[:12], err)
continue
}
case "running":
log().Debugf("reloading proxy container: id=%s", cnt.ID)
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@ehazlett ehazlett Feb 2, 2017

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This is needed to safely reload (see above comment).

if err := p.client.ContainerKill(context.Background(), cnt.ID, "HUP"); err != nil {
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@ehazlett ehazlett Feb 2, 2017

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Are you sure HAProxy handles this properly? I believe we've tried HUP before and found that it didn't always reload the config.

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@ehazlett ehazlett Feb 2, 2017

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That being said, if we can test it I would love to get rid of the TCP hacks. :)

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@bnoon bnoon Feb 2, 2017

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Pretty sure it is stable in v1.7.x. I have been using it (outside of interlock) for a while.

log().Errorf("error reloading container: id=%s err=%s", cnt.ID[:12], err)
continue
}
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@ehazlett ehazlett Feb 2, 2017

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Are you sure this catches all cases? A default with log probably wouldn't hurt.

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@bnoon bnoon Feb 2, 2017

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I will add it and update the PR.

default:
log().Infof("haproxy container id=%s name=%s in state %s", cnt.ID[:12], cnt.Names[0], cInfo.State.Status)
continue
}

log().Infof("restarted proxy container: id=%s name=%s", cnt.ID[:12], cnt.Names[0])
}

if err := p.resumeSYN(); err != nil {
log().Warnf("error signaling clients to resume; you will notice dropped packets: %s", err)
log().Infof("reloaded proxy container: id=%s name=%s", cnt.ID[:12], cnt.Names[0])
}

return nil
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