## Description
---
This pull request introduces a new custom tool kind `mssql-list-tables`
that allows users to list tables within a SQL server database.
### Example Configuration
```yaml
tools:
list_tables:
kind: mssql-list-tables
source: mssql-source
description: Use this tool to retrieve schema information for all or specified tables. Output format can be simple (only table names) or detailed.
```
### Example Request
```
curl -X POST http://127.0.0.1:5000/api/tool/list_tables/invoke \
-H "Content-Type: application/json" \
-d '{
"table_names": "users",
"output_format": "simple"
}'
```
## PR Checklist
---
> Thank you for opening a Pull Request! Before submitting your PR, there
are a
> few things you can do to make sure it goes smoothly:
- [x] Make sure you reviewed
[CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md)
- [ ] Make sure to open an issue as a
[bug/issue](https://github.com/googleapis/genai-toolbox/issues/new/choose)
before writing your code! That way we can discuss the change, evaluate
designs, and agree on the general idea
- [x] Ensure the tests and linter pass
- [x] Code coverage does not decrease (if any source code was changed)
- [x] Appropriate docs were updated (if necessary)
- [x] Make sure to add `!` if this involve a breaking change
🛠️ Fixes #<issue_number_goes_here>
---------
Co-authored-by: Averi Kitsch <akitsch@google.com>
## 1. Why do we need to support the `encrypt` parameter?
MSSQL databases that `genai-toolbox` attempts to connect to may have
their encryption levels set differently. For example, a testing/demo
purpose MSSQL database may not require encryption at all. However,
`genai-toolbox` currently uses the default encryption parameter
(`encrypt=false`) to connect to this type of database and will throw an
error:
```
ERROR "toolbox failed to initialize: unable to initialize configs: unable to initialize source "my-mssql-source": unable to connect successfully: TLS Handshake failed: cannot read handshake packet: EOF"
```
> In this case, the encryption parameter should be set to
`encrypt=disable`.
## 2. Is this a necessary feature?
`genai-toolbox` uses the `github.com/microsoft/go-mssqldb` package as a
dependency to connect to MSSQL databases. According to the
[README](https://github.com/microsoft/go-mssqldb?tab=readme-ov-file#common-parameters)
of the `github.com/microsoft/go-mssqldb` package, `encrypt` is one of
the common parameters. Therefore, I believe supporting the `encrypt`
parameter in `genai-toolbox` is necessary.
## 3. How to replicate the error mentioned above?
### 3.1 Use this `docker-compose.yaml` file to start a demo MSSQL
instance
```
services:
demo-mssql-database:
image: mcr.microsoft.com/mssql/server:2017-CU1-ubuntu
ports:
- "20256:1433"
environment:
ACCEPT_EULA: "Y"
MSSQL_SA_PASSWORD: "hellopassword!"
restart: unless-stopped
healthcheck:
test: ["CMD", "/opt/mssql-tools/bin/sqlcmd", "-S", "localhost", "-U", "sa", "-P", "hellopassword!", "-Q", "SELECT 1"]
interval: 5s
retries: 10
demo-mssql-database-init:
image: mcr.microsoft.com/mssql/server:2017-CU1-ubuntu
network_mode: service:demo-mssql-database
command: >
/bin/bash -c "/opt/mssql-tools/bin/sqlcmd -S localhost -U sa -P hellopassword! -d master -Q 'CREATE DATABASE DemoDatabase;'"
depends_on:
demo-mssql-database:
condition: service_healthy
```
### 3.2 Use `genai-toolbox` to connect to the above demo MSSQL database
with this `tools.yaml` configuration file:
```
sources:
my-mssql-source:
kind: mssql
host: localhost
port: 20256
database: master
user: sa
password: 'hellopassword!'
```
### 3.3 We shall see the error:
```
ERROR "toolbox failed to initialize: unable to initialize configs: unable to initialize source "my-mssql-source": unable to connect successfully: TLS Handshake failed: cannot read handshake packet: EOF"
```
---------
Co-authored-by: Yuan Teoh <45984206+Yuan325@users.noreply.github.com>
Environment variable replacement is needed so that users don't have to
hardcode their secrets in configuring `tools.yaml`.
Both formats `$ENV_NAME` and `${ENV_NAME}` are standard ways to declare
an environment variable.
However, some database statement placeholders that are already using the
`$ENV_NAME` format.
Therefore, we only support env var declaration using `${ENV_NAME}` to
disambiguate it from other usages.
Fixes issue: https://github.com/googleapis/genai-toolbox/issues/431
