clixon/doc/DEVELOP.md

# README for Clixon developers

(See also CONTRIBUTING.md)

  * [How to work in git (how-to-work-in-git)](#how-to-work-in-git)
  * [How the meta-configure stuff works](#meta-configure)
  * [How to debug](#debug)
  * [New release](#new-release)

## 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](https://travis-ci.org/clicon/clixon).

However, releases are made periodically (ca every 3 months) which are tested more.

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 <restconf> 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"}}'
```

### Debug parsing

Yacc: Enable _PARSE_DEBUG macro in corresponding yacc file.
Lex: Add -d in Makefile for corresponding lex file.
Run program with -D parse -D detail

### 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 CI tests run OK
* Ensure all extended tests run OK: valgrind, vagrant, afl
* Review CHANGELOG, write one-liner
  * Draft a new release and review generated release notes and use info to update CHANGELOG
* Review README.md 
* Build packages: scripts/build_deb.sh
* New yang/clicon/clixon-config@XXX.yang revision?
* Run autoconf
* Git stuff:
```
  git tag -a <version>
  git push origin <version>
```
* Add a github release and copy release info from CHANGELOG
* Tag associated repos:
  * cligen
  * clixon-example
  * clixon-docs
  * clixon-controller
* Build and push docker releases

After release:
* Run autoconf

### Optional release branch

Create release branch:
```
  git checkout -b release-4.2 4.2.0
  git push origin release-4.2
```

* Add release branch to .github/workflows/ci.yml

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/clixon/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
```