statd: Add new README to describe statd

Whats required from your system and what to expect when you run it
outside Infix.

src/statd/README.md

@@ -0,0 +1,62 @@
+# Introduction
+Statd is designed to be integrated into Infix and supply the operational
+database with data. To do this it uses companion binaries written in
+python, these are located in the `python` directory.
+
+
+## Run outside Infix
+### Prerequisites
+There are some requirements set on your computer to run statd locally.
+
+ - An Ubuntu based system
+ - lldpd
+ - python3
+ - [libite](https://github.com/troglobit/libite)
+ - [libsrx](https://github.com/kernelkit/infix/tree/main/src/libsrx)
+ - python-poetry
+ - [sysrepo](https://github.com/sysrepo/sysrepo) (At least the same version as Infix)
+ - [libyang](https://github.com/CESNET/libyang) (At least the same version as Infix)
+
+
+### Install YANG modules in local sysrepo
+This requires that you first build Infix, since netopeer2 and sysrepo are responsible
+for installing their own YANG files.
+
+```bash
+user@host ~/infix$ export TARGET_DIR="output/target/"
+user@host ~/infix$ export NETOPEER2_SEARCHPATH=$TARGET_DIR/usr/share/yang/modules/netopeer2/
+user@host ~/infix$ export SYSREPO_SEARCHPATH=$TARGET_DIR/usr/share/yang/modules/sysrepo/
+user@host ~/infix$ export LIBNETCONF2_SEARCHPATH=$TARGET_DIR/usr/share/yang/modules/libnetconf2/
+user@host ~/infix$ export CONFD_SEARCHPATH=$TARGET_DIR/usr/share/yang/modules/confd/
+user@host ~/infix$ export TEST_MODE_SEARCHPATH=$TARGET_DIR/usr/share/yang/modules/test-mode/
+user@host ~/infix$ export ROUSETTE_SEARCHPATH=$TARGET_DIR/usr/share/yang/modules/rousette/
+user@host ~/infix$ export SEARCH_PATH="$NETOPEER2_SEARCHPATH $SYSREPO_SEARCHPATH $LIBNETCONF2_SEARCHPATH $CONFD_SEARCHPATH $TEST_MODE_SEARCHPATH $ROUSETTE_SEARCHPATH"
+
+user@host ~/infix$ ./utils/srload src/confd/yang/sysrepo.inc
+user@host ~/infix$ ./utils/srload src/confd/yang/libnetconf2.inc
+user@host ~/infix$ ./utils/srload src/confd/yang/netopeer2.inc
+user@host ~/infix$ ./utils/srload src/confd/yang/confd.inc
+user@host ~/infix$ ./utils/srload src/confd/yang/rousette.inc
+user@host ~/infix$ ./utils/srload src/confd/yang/test-mode.inc
+```
+
+### Build and install python companion binaries
+```bash
+user@host ~/infix/src/statd/python$ ./local_install.sh
+```
+This will install the binaries in ~/.local/bin
+
+### Build and install statd
+
+```bash
+user@host ~/infix/src/statd$ ./configure --with-yanger-dir=$HOME/.local/bin
+user@host ~/infix/src/statd$ make
+user@host ~/infix/src/statd$ sudo make install
+```
+
+### Running statd
+Since the `yanger` binary, for example, reads the shadow database, you
+can expect different results if running `statd` as root or not.
+```bash
+user@host ~/infix/src/statd$ statd
+```