Red Hat Satellite Server – Fatal error in Python code occurred [[6]]

Posted on Leave a commentPosted in Deployment, Linux, Python, Red Hat Satelitte Server, RHEL 7, Spacewalk, System Administration, Systems Management

I have embraced Red Hat Satellite server in a big way over the past year and try to use it wherever possible though not for everything.

One of the features I started using to simply life whilst I look at other configuration management systems, was Configuration Channels.  These allow you to provide a central repository of files and binaries which can be deployed to a server during the initial kickstart server deployment process.

Some changes had been made a month or so ago, to ensure that a specific configuration channel would be included in future deployments by way of updating the Activation Key for that deployment type in Satellite server.  Seems innocent enough at this point.  It is worth noting that there were other configuration channels associated with this activation key.

At the same time I had also added a couple of packages to the software package list which were also required at time of deployment.

Now, I rely on scripts which have been deployed to a server to complete some post server build tasks.  The first thing I noticed after a test deployment, was a complete lack of any scripts where I expected them to be.  The configuration channels had created the required folder structure but had stopped completely and had gone no further.  The error the Satellite server reported back to me was… well not massively helpful;

Fatal error in Python code occurred [[6]]

Nothing more, nothing less.

At this point I started trying to remember what I had added (thankfully not to hard as I document things quite heavily 🙂 ).  Here is roughly the steps I took to confirm whether the issue resided;

  • Remove the additional packages I had specified for this particular build – made no difference
  • Remove what I the most recently added configuration channel – made no difference
  • Tested another Red Hat Enterprise Linux 7 build (not using this particular kickstart profile) – success, so the issue would appear to be limited to this one profile
  • Remove the other configuration channels that were added some time before the last one was added – failed, still the configuration channels would not deploy. But wait, there was light at the end of the tunnel!

But, following this last step, the error message changed, from something not very helpful to something quite helpful indeed!  The message stated that permissions could not be applied as per those stipulated against specific files in the configuration channel.

So it transpires that it was a permissions resolution issue. Well, more a group resolution issue really.  There were a couple of files which were set to be deployed with a specific group.  The group in question is served from a LDAP server and the newly built machine wasn’t configured at that point to talk to the LDAP server, for this particular deployment we didn’t want auto registration with the LDAP services.

So the lesson here is make small changes, test frequently and make sure you document what you have done.  Or use a configuration management system which is version controlled, so you can easily roll back.

Just so we are clear, I was running Red Hat Satellite Server 5.7 (full patched) on RHEL 6.8 and trying to deploy RHEL 7.3.  My adventure to upgrade Satellite server to version 6.2 will be coming to a blog post soon.

So, it would appear this story comes with a lesson attached (free of charge) that all should take note of – “Always make one change at a time and test or as near to one as you can”.

Featured image credit: Charly W Karl posted e.Deorbit closing on target satellite on Flickr.  Thanks very much.

GNS3 – Problems Compiling IOUYAP

Posted on Leave a commentPosted in C++, Fedora, Linux, Networks

Following the series of posts over recent months relating to the installation of GNS3; 1) Installing GNS3 on Fedora, CentOS and RHEL and 2) GNS3 Installation on Fedora 22 I have decided to put together a complete guide from start to finish chronicling my every step to ensure my GNS3 installation is correct and fully working.

It is at this point that I feel that I should not just share the normal story of “everything went fine… what problems?? I didn’t have a single issue installing the software!!!”  Well, for the most part I could have got away with a statement like that.  Unfortunately though when I reached the point of installing iouyap, things didn’t go quite as smoothly as one would hope.

As per my previous guides and the instructions that ship with iouyap (version 0.95) I ran the following;

$ bison --yacc -dv netmap_parse.y
$ flex netmap_scan.l
$ gcc -Wall -g *.c -o iouyap -liniparser -lpthread

I was the confronted with a wall of potential errors, and not knowing exactly what they meant, I thought it best to investigate…  The output from the last command line above was;

[toby@thebay iouyap-0.95]$ sudo gcc -Wall -g *.c -o iouyap -liniparser -lpthread
In file included from iouyap.c:49:0:
iouyap.c: In function ‘foreign_listener’:
iouyap.c:420:24: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘ssize_t {aka long int}’ [-Wformat=]
debug_log_fmt ("received %d bytes (sfd=%d)\n",
^
iouyap.h:103:28: note: in definition of macro ‘STMT’
#define STMT( code )  do { code } while (0)
^
iouyap.h:128:5: note: in expansion of macro ‘STMT’
STMT( log_prefix(); fprintf(stderr, fmt, ## __VA_ARGS__); )
^
iouyap.h:138:26: note: in expansion of macro ‘log_fmt’
STMT( if (DEBUG_LOG) log_fmt(fmt, ## __VA_ARGS__); )
^
iouyap.c:420:9: note: in expansion of macro ‘debug_log_fmt’
debug_log_fmt ("received %d bytes (sfd=%d)\n",
^
iouyap.c:458:28: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘ssize_t {aka long int}’ [-Wformat=]
log_fmt ("sendto() only sent %d of %d bytes!"
^
iouyap.h:103:28: note: in definition of macro ‘STMT’
#define STMT( code )  do { code } while (0)
^
iouyap.c:458:19: note: in expansion of macro ‘log_fmt’
log_fmt ("sendto() only sent %d of %d bytes!"
^
iouyap.c:458:28: warning: format ‘%d’ expects argument of type ‘int’, but argument 4 has type ‘ssize_t {aka long int}’ [-Wformat=]
log_fmt ("sendto() only sent %d of %d bytes!"
^
iouyap.h:103:28: note: in definition of macro ‘STMT’
#define STMT( code )  do { code } while (0)
^
iouyap.c:458:19: note: in expansion of macro ‘log_fmt’
log_fmt ("sendto() only sent %d of %d bytes!"
^
iouyap.c: In function ‘iou_listener’:
iouyap.c:536:24: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘ssize_t {aka long int}’ [-Wformat=]
debug_log_fmt ("received %d bytes for port %d (sfd=%d)\n",
^
iouyap.h:103:28: note: in definition of macro ‘STMT’
#define STMT( code )  do { code } while (0)
^
iouyap.h:128:5: note: in expansion of macro ‘STMT’
STMT( log_prefix(); fprintf(stderr, fmt, ## __VA_ARGS__); )
^
iouyap.h:138:26: note: in expansion of macro ‘log_fmt’
STMT( if (DEBUG_LOG) log_fmt(fmt, ## __VA_ARGS__); )
^
iouyap.c:536:9: note: in expansion of macro ‘debug_log_fmt’
debug_log_fmt ("received %d bytes for port %d (sfd=%d)\n",
^
iouyap.c:563:24: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘ssize_t {aka long int}’ [-Wformat=]
log_fmt ("write() only sent %d of %d bytes! (sfd=%d)\n",
^
iouyap.h:103:28: note: in definition of macro ‘STMT’
#define STMT( code )  do { code } while (0)
^
iouyap.c:563:15: note: in expansion of macro ‘log_fmt’
log_fmt ("write() only sent %d of %d bytes! (sfd=%d)\n",
^
iouyap.c:563:24: warning: format ‘%d’ expects argument of type ‘int’, but argument 4 has type ‘ssize_t {aka long int}’ [-Wformat=]
log_fmt ("write() only sent %d of %d bytes! (sfd=%d)\n",
^
iouyap.h:103:28: note: in definition of macro ‘STMT’
#define STMT( code )  do { code } while (0)
^
iouyap.c:563:15: note: in expansion of macro ‘log_fmt’
log_fmt ("write() only sent %d of %d bytes! (sfd=%d)\n",
^
In file included from netmap.c:34:0:
netmap.c: In function ‘dump_port_table’:
netmap.c:372:16: warning: format ‘%d’ expects argument of type ‘int’, but argument 6 has type ‘size_t {aka long unsigned int}’ [-Wformat=]
log_fmt ("%d:%d/%d talks to %d other node(s):\n", yap_appl_id,
^
iouyap.h:103:28: note: in definition of macro ‘STMT’
#define STMT( code )  do { code } while (0)
^
netmap.c:372:7: note: in expansion of macro ‘log_fmt’
log_fmt ("%d:%d/%d talks to %d other node(s):\n", yap_appl_id,
^

After some monkeying about, I reduced these errors to;

In file included from netmap.c:34:0:
netmap.c: In function ‘dump_port_table’:
netmap.c:372:16: warning: format ‘%d’ expects argument of type ‘int’, but argument 6 has type ‘size_t {aka long unsigned int}’ [-Wformat=]
log_fmt ("%d:%d/%d talks to %d other node(s):\n", yap_appl_id,
^
iouyap.h:103:28: note: in definition of macro ‘STMT’
#define STMT( code )  do { code } while (0)
^
netmap.c:372:7: note: in expansion of macro ‘log_fmt’
log_fmt ("%d:%d/%d talks to %d other node(s):\n", yap_appl_id,
^

the diff output is as follows;

diff iouyap.c ../../iouyap-0.95_original/iouyap-0.95/iouyap.c
383,384c383
<   /* ssize_t bytes_received, bytes_sent; */
<   int bytes_received, bytes_sent; --- >   ssize_t bytes_received, bytes_sent;
503,504c502
<   /* ssize_t bytes_received, bytes_sent; */
<   int bytes_received, bytes_sent; --- >   ssize_t bytes_received, bytes_sent;

Now I’m no C++ developer, not even close, and the last thing to resolve in netmap.c just didn’t make sense. So I paid the gns3 website a visit, and magically less than 24 hours after I had downloaded the 1.3.8 version there was a new release… 1.3.9.

Sadly the IOUYAP package there also contained the issue, in the end I resorted to good old fashioned tactics… I got hold of the source code from github and the issues I was facing were fixed in the version I checked out.  You can see the results below;

[toby@thebay GNS3-1.3.9]$ git clone https://github.com/GNS3/iouyap.git
Cloning into 'iouyap'...
remote: Counting objects: 78, done.
remote: Total 78 (delta 0), reused 0 (delta 0), pack-reused 78
Unpacking objects: 100% (78/78), done.
Checking connectivity... done.
[toby@thebay GNS3-1.3.9]$ ls
dynamips-0.2.14      gns3-gui-1.3.9      gns3-server-1.3.9      iouyap       iouyap-0.95.zip  ubridge-0.9.0.zip  vpcs-0.6.1.zip
dynamips-0.2.14.zip  gns3-gui-1.3.9.zip  gns3-server-1.3.9.zip  iouyap-0.95  ubridge-0.9.0    vpcs-0.6.1
[toby@thebay GNS3-1.3.9]$ cd iouyap
[toby@thebay iouyap]$ ls
config.c  dictionary.h  iouyap.c  iouyap.ini  Makefile  netmap.c  netmap_parse.y  README.rst
config.h  iniparser.h   iouyap.h  LICENSE     NETMAP    netmap.h  netmap_scan.l
[toby@thebay iouyap]$ make
gcc  -g -DDEBUG -Wall   -c -o iouyap.o iouyap.c
bison -y -d netmap_parse.y
mv -f y.tab.c netmap_parse.c
gcc  -g -DDEBUG -Wall   -c -o netmap_parse.o netmap_parse.c
flex  -t netmap_scan.l > netmap_scan.c
gcc  -g -DDEBUG -Wall   -c -o netmap_scan.o netmap_scan.c
gcc  -g -DDEBUG -Wall   -c -o netmap.o netmap.c
gcc  -g -DDEBUG -Wall   -c -o config.o config.c
gcc    iouyap.o netmap_parse.o netmap_scan.o netmap.o config.o  -liniparser -lpthread -o iouyap
rm netmap_scan.c netmap_parse.c
[toby@thebay iouyap]$ sudo make install
[sudo] password for toby:
chmod +x iouyap
sudo cp iouyap /usr/local/bin
sudo setcap cap_net_admin,cap_net_raw=ep iouyap

Taa Daa!