[ClusterLabs] ocf scripts shell and local variables

Dejan Muhamedagic dejanmm at fastmail.fm
Tue Aug 30 06:20:19 EDT 2016


Hi,

On Mon, Aug 29, 2016 at 05:08:35PM +0200, Gabriele Bulfon wrote:
> Sure, infact I can change all shebang to point to /bin/bash and it's ok.
> The question is about current shebang /bin/sh which may go into trouble (as if one would point to a generic python but uses many specific features of a version of python).
> Also, the question is about bash being a good option for RAs, being much more heavy.

I'd really suggest installing a smaller shell such as /bin/dash
and using that as /bin/sh. Isn't there a Bourne shell in Solaris?
If you modify the RAs it could be trouble on subsequent updates.

Thanks,

Dejan

> Gabriele
> ----------------------------------------------------------------------------------------
> Sonicle S.r.l.
> :
> http://www.sonicle.com
> Music:
> http://www.gabrielebulfon.com
> Quantum Mechanics :
> http://www.cdbaby.com/cd/gabrielebulfon
> ----------------------------------------------------------------------------------
> Da: Dejan Muhamedagic
> A: kgaillot at redhat.com Cluster Labs - All topics related to open-source clustering welcomed
> Data: 29 agosto 2016 16.43.52 CEST
> Oggetto: Re: [ClusterLabs] ocf scripts shell and local variables
> Hi,
> On Mon, Aug 29, 2016 at 08:47:43AM -0500, Ken Gaillot wrote:
> On 08/29/2016 04:17 AM, Gabriele Bulfon wrote:
> Hi Ken,
> I have been talking with the illumos guys about the shell problem.
> They all agreed that ksh (and specially the ksh93 used in illumos) is
> absolutely Bourne-compatible, and that the "local" variables used in the
> ocf shells is not a Bourne syntax, but probably a bash specific.
> This means that pointing the scripts to "#!/bin/sh" is portable as long
> as the scripts are really Bourne-shell only syntax, as any Unix variant
> may link whatever Bourne-shell they like.
> In this case, it should point to "#!/bin/bash" or whatever shell the
> script was written for.
> Also, in this case, the starting point is not the ocf-* script, but the
> original RA (IPaddr, but almost all of them).
> What about making the code base of RA and ocf-* portable?
> It may be just by changing them to point to bash, or with some kind of
> configure modifier to be able to specify the shell to use.
> Meanwhile, changing the scripts by hands into #!/bin/bash worked like a
> charm, and I will start patching.
> Gabriele
> Interesting, I thought local was posix, but it's not. It seems everyone
> but solaris implemented it:
> http://stackoverflow.com/questions/18597697/posix-compliant-way-to-scope-variables-to-a-function-in-a-shell-script
> Please open an issue at:
> https://github.com/ClusterLabs/resource-agents/issues
> The simplest solution would be to require #!/bin/bash for all RAs that
> use local,
> This issue was raised many times, but note that /bin/bash is a
> shell not famous for being lean: it's great for interactive use,
> but not so great if you need to run a number of scripts. The
> complexity in bash, which is superfluous for our use case,
> doesn't go well with the basic principles of HA clusters.
> but I'm not sure that's fair to the distros that support
> local in a non-bash default shell. Another possibility would be to
> modify all RAs to avoid local entirely, by using unique variable
> prefixes per function.
> I doubt that we could do a moderately complex shell scripts
> without capability of limiting the variables' scope and retaining
> sanity at the same time.
> Or, it may be possible to guard every instance of
> local with a check for ksh, which would use typeset instead. Raising the
> issue will allow some discussion of the possibilities.
> Just to mention that this is the first time someone reported
> running a shell which doesn't support local. Perhaps there's an
> option that they install a shell which does.
> Thanks,
> Dejan
> ----------------------------------------------------------------------------------------
> *Sonicle S.r.l. *: http://www.sonicle.com
> *Music: *http://www.gabrielebulfon.com
> *Quantum Mechanics : *http://www.cdbaby.com/cd/gabrielebulfon
> ----------------------------------------------------------------------------------
> Da: Ken Gaillot
> A: gbulfon at sonicle.com Cluster Labs - All topics related to open-source
> clustering welcomed
> Data: 26 agosto 2016 15.56.02 CEST
> Oggetto: Re: ocf scripts shell and local variables
> On 08/26/2016 08:11 AM, Gabriele Bulfon wrote:
> I tried adding some debug in ocf-shellfuncs, showing env and ps
> -ef into
> the corosync.log
> I suspect it's always using ksh, because in the env output I
> produced I
> find this: KSH_VERSION=.sh.version
> This is normally not present in the environment, unless ksh is running
> the shell.
> The RAs typically start with #!/bin/sh, so whatever that points to on
> your system is what will be used.
> I also tried modifiying all ocf shells with "#!/usr/bin/bash" at the
> beginning, no way, same output.
> You'd have to change the RA that includes them.
> Any idea how can I change the used shell to support "local" variables?
> You can either edit the #!/bin/sh line at the top of each RA, or figure
> out how to point /bin/sh to a Bourne-compatible shell. ksh isn't
> Bourne-compatible, so I'd expect lots of #!/bin/sh scripts to fail with
> it as the default shell.
> Gabriele
> ----------------------------------------------------------------------------------------
> *Sonicle S.r.l. *: http://www.sonicle.com
> *Music: *http://www.gabrielebulfon.com
> *Quantum Mechanics : *http://www.cdbaby.com/cd/gabrielebulfon
> ------------------------------------------------------------------------
> *Da:* Gabriele Bulfon
> *A:* kgaillot at redhat.com Cluster Labs - All topics related to
> open-source clustering welcomed
> *Data:* 26 agosto 2016 10.12.13 CEST
> *Oggetto:* Re: [ClusterLabs] ocf::heartbeat:IPaddr
> I looked around what you suggested, inside ocf-binaris and
> ocf-shellfuncs etc.
> So I found also these logs in corosync.log :
> Aug 25 17:50:33 [2250] crmd: notice: process_lrm_event:
> xstorage1-xstorage2_wan2_IP_start_0:22 [
> /usr/lib/ocf/resource.d/heartbeat/IPaddr[71]: local: not found [No
> such file or
> directory]\n/usr/lib/ocf/resource.d/heartbeat/IPaddr[354]: local:
> not found [No such file or
> directory]\n/usr/lib/ocf/resource.d/heartbeat/IPaddr[355]: local:
> not found [No such file or
> directory]\n/usr/lib/ocf/resource.d/heartbeat/IPaddr[356]: local:
> not found [No such file or directory]\nocf-exit-reason:Setup
> problem: coul
> Aug 25 17:50:33 [2246] lrmd: notice: operation_finished:
> xstorage2_wan2_IP_start_0:3613:stderr [
> /usr/lib/ocf/resource.d/heartbeat/IPaddr[71]: local: not found [No
> such file or directory] ]
> Looks like the shell is not happy with the "local" variable
> definition.
> I tried running ocf-shellfuncs manually with sh and bash and they
> all run without errors.
> How can I see what shell is running these scripts?
> ----------------------------------------------------------------------------------------
> *Sonicle S.r.l. *: http://www.sonicle.com
> *Music: *http://www.gabrielebulfon.com
> *Quantum Mechanics : *http://www.cdbaby.com/cd/gabrielebulfon
> ----------------------------------------------------------------------------------
> Da: Ken Gaillot
> A: users at clusterlabs.org
> Data: 25 agosto 2016 18.07.42 CEST
> Oggetto: Re: [ClusterLabs] ocf::heartbeat:IPaddr
> On 08/25/2016 10:51 AM, Gabriele Bulfon wrote:
> Hi,
> I'm advancing with this monster cluster on XStreamOS/illumos ;)
> In the previous older tests I used heartbeat, and I had these
> lines to
> take care of the swapping public IP addresses:
> primitive xstorage1_wan1_IP ocf:heartbeat:IPaddr params
> ip="1.2.3.4"
> cidr_netmask="255.255.255.0" nic="e1000g1"
> primitive xstorage2_wan2_IP ocf:heartbeat:IPaddr params
> ip="1.2.3.5"
> cidr_netmask="255.255.255.0" nic="e1000g1"
> location xstorage1_wan1_IP_pref xstorage1_wan1_IP 100: xstorage1
> location xstorage2_wan2_IP_pref xstorage2_wan2_IP 100: xstorage2
> They get configured, but then I get this in crm status:
> xstorage1_wan1_IP (ocf::heartbeat:IPaddr): Stopped
> xstorage2_wan2_IP (ocf::heartbeat:IPaddr): Stopped
> Failed Actions:
> * xstorage1_wan1_IP_start_0 on xstorage1 'not installed' (5):
> call=20,
> status=complete, exitreason='Setup problem: couldn't find command:
> /usr/bin/gawk',
> last-rc-change='Thu Aug 25 17:50:32 2016', queued=1ms, exec=158ms
> * xstorage2_wan2_IP_start_0 on xstorage1 'not installed' (5):
> call=22,
> status=complete, exitreason='Setup problem: couldn't find command:
> /usr/bin/gawk',
> last-rc-change='Thu Aug 25 17:50:33 2016', queued=1ms, exec=29ms
> * xstorage1_wan1_IP_start_0 on xstorage2 'not installed' (5):
> call=22,
> status=complete, exitreason='Setup problem: couldn't find command:
> /usr/bin/gawk',
> last-rc-change='Thu Aug 25 17:50:30 2016', queued=1ms, exec=36ms
> * xstorage2_wan2_IP_start_0 on xstorage2 'not installed' (5):
> call=20,
> status=complete, exitreason='Setup problem: couldn't find command:
> /usr/bin/gawk',
> last-rc-change='Thu Aug 25 17:50:29 2016', queued=0ms, exec=150ms
> The crm configure process already checked of the presence of the
> required IPaddr shell, and it was ok.
> Now looks like it's looking for "/usr/bin/gawk", and that is
> actually there!
> Is there any known incompatibility with the mixed heartbeat
> ocf ? Should
> I use corosync specific ocf files or something else?
> "heartbeat" in this case is just an OCF provider name, and has
> nothing
> to do with the heartbeat messaging layer, other than having its
> origin
> in the same project. There actually has been a recent proposal
> to rename
> the provider to "clusterlabs" to better reflect the current reality.
> The "couldn't find command" message comes from the ocf-binaries
> shell
> functions. If you look at have_binary() there, it uses sed and
> which,
> and I'm guessing that fails on your OS somehow. You may need to
> patch it.
> Thanks again!
> Gabriele
> ----------------------------------------------------------------------------------------
> *Sonicle S.r.l. *: http://www.sonicle.com
> *Music: *http://www.gabrielebulfon.com
> *Quantum Mechanics : *http://www.cdbaby.com/cd/gabrielebulfon
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