README: add better documentation

README.md

@@ -1,3 +1,45 @@
 # mysqladm-rs
 
 Work in progress rewrite of https://git.pvv.ntnu.no/Projects/mysql-admutils
+
+## Installation
+
+The resulting binary will probably need to be marked as either SUID or SGID to work in a multi-user environment.
+The UID/GID of the binary should have access to the config file, which contains secrets to log in to an admin-like MySQL user.
+Preferrably, this UID/GID should not be root, in order to minimize the potential damage that can be done in case of security vulnerabilities in the program.
+
+## Development and testing
+
+Ensure you have a [rust toolchain](https://www.rust-lang.org/tools/install) installed.
+
+In order to set up a test instance of mariadb in a docker container, run the following command:
+
+```bash
+docker run --rm --name mariadb -e MYSQL_ROOT_PASSWORD=secret -d mariadb:latest
+```
+
+You should then create a config file, and adjust the hostname to the IP address of the docker container.
+
+```bash
+cp ./example-config.toml ./config.toml
+DOCKER_IP_ADDRESS="$(docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' mariadb)"
+sed -i "s/host = \"localhost\"/host = \"${DOCKER_IP_ADDRESS}\"/" ./config.toml
+```
+
+You should now be able to connect to the mariadb instance, after building the program and using arguments to specify the config file.
+
+```bash
+cargo run -- --config-file ./config.toml <args>
+
+# example usage
+cargo run -- --config-file ./config.toml db create "${USER}_testdb"
+cargo run -- --config-file ./config.toml user create "${USER}_testuser"
+cargo run -- --config-file ./config.toml db edit-perm -p "${USER}_testdb:${USER}_testuser:A"
+cargo run -- --config-file ./config.toml db show-perm
+```
+
+To stop and remove the container, run the following command:
+
+```bash
+docker stop mariadb
+```