Alicloud Storage Oss Ossutil

SKILL.md

---
name: alicloud-storage-oss-ossutil
description: Alibaba Cloud OSS CLI (ossutil 2.0) skill. Install, configure, and operate OSS from the command line based on the official ossutil overview.
version: 1.0.0
---

Category: tool

# OSS (ossutil 2.0) CLI Skill

## Validation

```bash
python skills/storage/oss/alicloud-storage-oss-ossutil/scripts/check_ossutil.py --output output/alicloud-storage-oss-ossutil/validate.txt
```

Pass criteria: command exits 0 and `output/alicloud-storage-oss-ossutil/validate.txt` is generated.

## Output And Evidence

- Save command outputs, object listings, and sync logs under `output/alicloud-storage-oss-ossutil/`.
- Keep at least one upload or listing result as evidence.

## Goals

- Use ossutil 2.0 to manage OSS: upload, download, sync, and resource management.
- Provide a unified CLI flow for install, config, credentials, and region/endpoint handling.

## Quick Start Flow

1. Install ossutil 2.0.
2. Configure AK/SK and default region (`ossutil config` or config file).
3. Run `ossutil ls` to list buckets, then list objects using the bucket region.
4. Execute upload/download/sync or API-level commands.

## Install ossutil 2.0

- See `references/install.md` for platform-specific install steps.

## Configure ossutil

- Interactive configuration:

```bash
ossutil config
```

- Default config file paths:
  - Linux/macOS：`~/.ossutilconfig`
  - Windows：`C:\Users\issuser\.ossutilconfig`

Main configuration fields include:
- `AccessKey ID`
- `AccessKey Secret`
- `Region`（example default `cn-hangzhou`; ask the user if the best region is unclear）
- `Endpoint`（optional; auto-derived from region if omitted）

## AccessKey configuration notes

Use RAM users/roles with least privilege and avoid passing AK in plain text on command line.

Recommended method (environment variables):

```bash
export ALICLOUD_ACCESS_KEY_ID="<your-ak>"
export ALICLOUD_ACCESS_KEY_SECRET="<your-sk>"
export ALICLOUD_REGION_ID="cn-beijing"
```

`ALICLOUD_REGION_ID` can be used as default region; if unset choose the most reasonable region, ask user if unclear.

Or use the standard shared credentials file:

`~/.alibabacloud/credentials`

```ini
[default]
type = access_key
access_key_id = <your-ak>
access_key_secret = <your-sk>
```


## Command structure (2.0)

- High-level command example:`ossutil config`
- API-level command example:`ossutil api put-bucket-acl`

## Common command examples

```bash
ossutil ls
ossutil ls oss://your-bucket -r --short-format --region cn-shanghai -e https://oss-cn-shanghai.aliyuncs.com
ossutil cp ./local.txt oss://your-bucket/path/local.txt
ossutil cp oss://your-bucket/path/remote.txt ./remote.txt
ossutil sync ./local-dir oss://your-bucket/path/ --delete
```

## Recommended execution flow (list buckets first, then objects)

1) List all buckets

```bash
ossutil ls
```

2) Get target bucket region from output (e.g. `oss-cn-shanghai`) and convert it to `--region` format (`cn-shanghai`).

3) When listing objects, explicitly set `--region` and `-e` to avoid cross-region signature/endpoint errors.

```bash
ossutil ls oss://your-bucket \
  -r --short-format \
  --region cn-shanghai \
  -e https://oss-cn-shanghai.aliyuncs.com
```

4) For very large buckets, limit output size first.

```bash
ossutil ls oss://your-bucket --limited-num 100
ossutil ls oss://your-bucket/some-prefix/ -r --short-format --region cn-shanghai -e https://oss-cn-shanghai.aliyuncs.com
```

## Common errors and handling

- `Error: region must be set in sign version 4.`
  - Cause: missing region configuration.
  - Fix: add `region` in config file, or pass `--region cn-xxx`.

- `The bucket you are attempting to access must be addressed using the specified endpoint`
  - Cause: request endpoint does not match bucket region.
  - Fix: use endpoint of the bucket region, e.g. `-e https://oss-cn-hongkong.aliyuncs.com`.

- `Invalid signing region in Authorization header`
  - Cause: signature region does not match bucket region.
  - Fix: correct both `--region` and `-e`; both must match bucket region.

## Credential and security guidance

- Prefer RAM user AK for access control.
- CLI options can override config file, but passing secrets on command line has leakage risk.
- In production, manage secrets via config files or environment variables.

## Clarifying questions (ask when uncertain)

1. Is your target a Bucket or an Object?
2. Do you need upload/download/sync, or management actions like ACL/lifecycle/CORS?
3. What are the target region and endpoint?
4. Are you accessing OSS from ECS in the same region (intranet endpoint may be preferred)?

## References

- OSSUTIL 2.0 overview and install/config:
  - https://help.aliyun.com/zh/oss/developer-reference/ossutil-overview

- Official source list:`references/sources.md`

## Prerequisites

- Configure least-privilege Alibaba Cloud credentials before execution.
- Prefer environment variables: `ALICLOUD_ACCESS_KEY_ID`, `ALICLOUD_ACCESS_KEY_SECRET`, optional `ALICLOUD_REGION_ID`.
- If region is unclear, ask the user before running mutating operations.

## Workflow

1) Confirm user intent, region, identifiers, and whether the operation is read-only or mutating.
2) Run one minimal read-only query first to verify connectivity and permissions.
3) Execute the target operation with explicit parameters and bounded scope.
4) Verify results and save output/evidence files.