clixon/doc/DEVELOP.md

README for Clixon developers

• Code documentation
• How to work in git (how-to-work-in-git)
• How the meta-configure stuff works
• How to debug
• New release

Documentation

How to document the code

/*! This is a small comment on one line
 *
 * This is a detailed description
 * spanning several lines.
 *
 * Example usage:
 * @code
 *   fn(a, &b);
 * @endcode
 *
 * @param[in] src         This is a description of the first parameter
 * @param[in,out] dest    This is a description of the second parameter
 * @retval TRUE           This is a description of the return value
 * @retval FALSE          This is a description of another return value
 * @see                   See also this function
 */

How to work in git

Clixon uses semantic versioning (https://semver.org).

Try to keep a single master branch always working. Currently testing is made using Travis CI.

However, releases are made periodically (ca every 1 month) which is more tested.

A release branch can be made, eg release-4.0 where 4.0.0, 4.0.1 are tagged

Commit messages: https://chris.beams.io/posts/git-commit/

How the autotools stuff works

configure.ac --.
                    |   .------> autoconf* -----> configure
     [aclocal.m4] --+---+
                    |   `-----> [autoheader*] --> [config.h.in]
     [acsite.m4] ---'

                           .-------------> [config.cache]
     configure* ------------+-------------> config.log
                            |
     [config.h.in] -.       v            .-> [config.h] -.
                    +--> config.status* -+               +--> make*
     Makefile.in ---'                    `-> Makefile ---'

Note: remember to run autoheader sometimes (when?) And when you do note (https://github.com/clicon/cligen/issues/17) which states that cligen_custom.h should be in quote.

Get config.sub and config.guess:

$ wget -O config.guess 'https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.guess;hb=HEAD'
$ wget -O config.sub 'https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub;hb=HEAD'

Or generate:

libtoolize --force
aclocal
autoheader
automake --force-missing --add-missing

Debug

How to debug

Configure in debug mode

   ./configure --enable-debug

Send debug level in run-time to backend:

  echo "<rpc username=\"root\" xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\"><debug xmlns=\"http://clicon.org/lib\"><level>1</level></debug></rpc>]]>]]>" | clixon_netconf -q -o CLICON_NETCONF_HELLO_OPTIONAL=true

Set backend debug

Using netconf:

<rpc xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"><debug xmlns="http://clicon.org/lib"><level>1</level></debug></rpc>

Using curl:

curl -Ssik -X POST -H "Content-Type: application/yang-data+json" http://localhost/restconf/operations/clixon-lib:debug -d '{"clixon-lib:input":{"level":1}}'

Set restconf debug

All three must be true:

1. clixon-restconf.yang is used (so that debug config can be set)
2. AND the XML is in running db not in clixon-config (so that restconf reads the new config from backend) 3 CLICON_BACKEND_RESTCONF_PROCESS is true (so that backend restarts restconf)

Otherwise you need to restart clixon_restconf manually

Using netconf:

clixon_netconf -q -o CLICON_NETCONF_HELLO_OPTIONAL=true <<EOF
<rpc xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"><edit-config><target><candidate/></target><config><restconf xmlns="http://clicon.org/restconf"><debug>1</debug></restconf></config></edit-config></rpc>]]>]]>
<rpc xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"><commit/></rpc>]]>]]>
EOF

Using restconf/curl

curl -Ssik -X PUT -H "Content-Type: application/yang-data+json" http://localhost/restconf/data/clixon-restconf:restconf/debug -d '{"clixon-restconf:debug":1}' 

Get restconf daemon status:

curl -Ssik -X POST -H "Content-Type: application/yang-data+json" http://localhost/restconf/operations/clixon-lib:process-control -d '{"clixon-lib:input":{"name":"restconf","operation":"status"}}'

Make your own simplified yang and configuration file.

cat <<EOF > /tmp/my.yang
module mymodule{
   container x {
    list y {
      key "a";
      leaf a {
        type string;
      }
    }
  }
}
EOF
cat <<EOF > /tmp/myconf.xml
<config>
  <CLICON_CONFIGFILE>/tmp/myconf.xml</CLICON_CONFIGFILE>
  <CLICON_YANG_DIR>/usr/local/share/example/yang</CLICON_YANG_DIR>
  <CLICON_YANG_MODULE_MAIN>example</CLICON_YANG_MODULE_MAIN>
  <CLICON_SOCK>/usr/local/var/example/example.sock</CLICON_SOCK>
  <CLICON_BACKEND_PIDFILE>/usr/local/var/example/example.pidfile</CLICON_BACKEND_PIDFILE>
  <CLICON_XMLDB_DIR>/usr/local/var/example</CLICON_XMLDB_DIR>
</config>
EOF
 sudo clixon_backend -F -s init -f /tmp/myconf.xml -y /tmp/my.yang

Run valgrind and callgrind

 valgrind --leak-check=full --show-leak-kinds=all clixon_netconf -qf /tmp/myconf.xml -y /tmp/my.yang
 LD_BIND_NOW=y valgrind --tool=callgrind clixon_netconf -qf /tmp/myconf.xml -y /tmp/my.yang
 sudo kcachegrind
 valgrind --tool=massif clixon_netconf -qf /tmp/myconf.xml -y /tmp/my.yang
 massif-visualizer

To turn callgrind off/on:

 valgrind --tool=callgrind --instr-atstart=no clixon_netconf -qf /tmp/myconf.xml -y /tmp/my.yang
 ...
 callgrind_control -i on

valgrind and gdb

valgrind --vgdb=yes --vgdb-error=0 clixon_cli

gdb clixon_cli
(gdb) target remote | /usr/lib/valgrind/../../bin/vgdb --pid=1311 # see output from valgrind
(gdb) cont

New release

What to think about when doing a new release.

• Ensure all tests run OK
• review CHANGELOG, write one-liner
• review README.md wording about latest release
• New yang/clicon/clixon-config@XXX.yang revision?
• In configure.ac, for minor releases change CLIXON_VERSION in configure.ac to eg: (minor should have been bumped):

  CLIXON_VERSION="\"${CLIXON_VERSION_MAJOR}.${CLIXON_VERSION_MINOR}.${CLIXON_VERSION_PATCH}\""

• For patch releases change CLIXON_VERSION_PATCH
• Run autoconf
• Git stuff:

  git tag -a <version>
  git push origin <version>

• Add a github "release" and copy release info from CHANGELOG

After release:

• Bump minor version and add a "PRE":

  CLIXON_VERSION_MINOR="10" ++
  CLIXON_VERSION="\"${CLIXON_VERSION_MAJOR}.${CLIXON_VERSION_MINOR}.${CLIXON_VERSION_PATCH}.PRE\""

• Run autoconf

Create release branch:

  git checkout -b release-4.2 4.2.0
  git push origin release-4.2

Merge a branch back:

  git merge --no-ff release-4.2

Use of constants etc

Use MAXPATHLEN (not PATH_MAX) in sys/param.h

Emulating a serial console

socat PTY,link=/tmp/clixon-tty,rawer EXEC:"/usr/local/bin/clixon_cli -f /usr/local/etc/example.xml",pty,stderr & screen /tmp/clixon-tty

Coverage

LDFLAGS=-coverage LINKAGE=static CFLAGS="-O2 -Wall -coverage" ./configure
bash <(curl -s https://codecov.io/bash) -t <token>

Static analysis

sudo apt install clang-tools # on ubuntu
scan-build ./configure --enable-debug
scan-build make
scan-view /tmp/scan-build-2022-02-03-100113-27646-1 # example