[Kimchi-devel] [PATCH v2 2/4] Implement the package manager monitor backend

[Aline Manera]

On 04/10/2015 17:44, Jose Ricardo Ziviani wrote:
>   - The client will be able to know if there is a package manager instance
>      running and to follow the package manager logfiles to know what is
>      happening within.
>
> Signed-off-by: Jose Ricardo Ziviani <joserz at linux.vnet.ibm.com>
> ---
>   src/wok/plugins/kimchi/control/host.py |  1 +
>   src/wok/plugins/kimchi/model/host.py   | 10 +++++++
>   src/wok/plugins/kimchi/swupdate.py     | 53 ++++++++++++++++++++++++++++++++++
>   3 files changed, 64 insertions(+)
>
> diff --git a/src/wok/plugins/kimchi/control/host.py b/src/wok/plugins/kimchi/control/host.py
> index 0a40f1b..6c2ed43 100644
> --- a/src/wok/plugins/kimchi/control/host.py
> +++ b/src/wok/plugins/kimchi/control/host.py
> @@ -39,6 +39,7 @@ class Host(Resource):
>           self.packagesupdate = PackagesUpdate(self.model)
>           self.repositories = Repositories(self.model)
>           self.swupdate = self.generate_action_handler_task('swupdate')
> +        self.taillogs = self.generate_action_handler_task('taillogs')

That way we will create a POST API which is not the case here.
The POST method is to change a resource in some way. And this operation 
is to return the logs from a started operation. So it looks more like a 
GET request.

Also it is related to software update, so I'd say the API should be 
something like: GET /host/swupdateprogress

So we'd have the following APIs:

POST /host/swupdate (to update all packages)

GET /host/swupdateprogress                                      (to 
return the update progress)

>           self.cpuinfo = CPUInfo(self.model)
>
>       @property
> diff --git a/src/wok/plugins/kimchi/model/host.py b/src/wok/plugins/kimchi/model/host.py
> index ddfbf0f..c850669 100644
> --- a/src/wok/plugins/kimchi/model/host.py
> +++ b/src/wok/plugins/kimchi/model/host.py
> @@ -128,6 +128,16 @@ class HostModel(object):
>               self.host_info['memory'] = psutil.virtual_memory().total
>           return self.host_info
>
> +    def taillogs(self, *name):
> +        try:
> +            swupdate = SoftwareUpdate()
> +        except:
> +            raise OperationFailed('KCHPKGUPD0004E')
> +
> +        taskid = add_task('/plugins/kimchi/host/taillogs',
> +                          swupdate.tailUpdateLogs, self.objstore, None)
> +        return self.task.lookup(taskid)
> +
>       def swupdate(self, *name):
>           try:
>               swupdate = SoftwareUpdate()
> diff --git a/src/wok/plugins/kimchi/swupdate.py b/src/wok/plugins/kimchi/swupdate.py
> index f86c12e..687d3f5 100644
> --- a/src/wok/plugins/kimchi/swupdate.py
> +++ b/src/wok/plugins/kimchi/swupdate.py
> @@ -122,6 +122,59 @@ class SoftwareUpdate(object):
>           os.setsid()
>           signal.signal(signal.SIGTERM, signal.SIG_IGN)
>
> +    def tailUpdateLogs(self, cb, params):
> +        """
> +        When the package manager is already running (started outside kimchi or
> +        if wokd is restarted) we can only know what's happening by reading the
> +        logfiles. This method acts like a 'tail -f' on the default package
> +        manager logfile. If the logfile is not found, a simple '*' is
> +        displayed to track progress. This will be until the process finishes.
> +        """
> +        if not self._pkg_mnger.isRunning():
> +            return
> +
> +        fd = None
> +        try:
> +            fd = os.open(self._pkg_mnger.logfile, os.O_RDONLY)
> +
> +        # cannot open logfile, print something to let users know that the
> +        # system is being upgrading until the package manager finishes its
> +        # job
> +        except (TypeError, OSError):
> +            msgs = []
> +            while self._pkg_mnger.isRunning():
> +                msgs.append('*')
> +                cb(''.join(msgs))
> +                time.sleep(1)
> +            msgs.append('\n')
> +            cb(''.join(msgs), True)
> +            return
> +
> +        # go to the end of logfile and starts reading, if nothing is read or
> +        # a pattern is not found in the message just wait and retry until
> +        # the package manager finishes
> +        os.lseek(fd, 0, os.SEEK_END)
> +        msgs = []
> +        progress = []
> +        while True:
> +            read = os.read(fd, 1024)
> +            if not read:
> +                if not self._pkg_mnger.isRunning():
> +                    break
> +
> +                if not msgs:
> +                    progress.append('*')
> +                    cb(''.join(progress))
> +
> +                time.sleep(1)
> +                continue
> +
> +            msgs.append(read)
> +            cb(''.join(msgs))
> +
> +        os.close(fd)
> +        return cb(''.join(msgs), True)
> +
>       def doUpdate(self, cb, params):
>           """
>           Execute the update