Detailed description of the scenario's application and purpose.
Diagnose network connectivity, upload/download bandwidth, download time, and local symlink anomalies between the local workstation and OSS using
integrated with the Alibaba Cloud CLI.
Architecture: Local Workstation + Alibaba Cloud CLI 3.3.3+ +
+ OSS Bucket + Optional target object or presigned URL + Optional probe domain
| Scenario | Recommended Command | Output |
|---|
| Upload connectivity probe | aliyun ... ossutil probe --upload
| Upload duration, object name, log file |
| Download connectivity probe | aliyun ... ossutil probe --download
| Download duration, local file path, log file |
| Upload bandwidth suggestion | aliyun ... ossutil probe --probe-item upload-speed
| Suggested concurrency value |
| Download bandwidth suggestion | aliyun ... ossutil probe --probe-item download-speed
| Suggested concurrency value |
| Download time measurement | aliyun ... ossutil probe --probe-item download-time
| Concurrency/part-size/duration statistics |
| Symlink anomaly check | aliyun ... ossutil probe --probe-item cycle-symlink
| Whether abnormal symlinks exist |
Important implementation boundary
- is a composite client-side diagnostic command provided by ; there is no equivalent .
- can only detect abnormal symlinks — it cannot safely auto-fix target paths.
- Probe output can locate symptoms and suggest concurrency, but cannot guarantee an automatic precise root cause for all network anomalies.
- requires a real existing object, and the official recommendation is objects larger than 5 MiB. If no suitable object exists, the user must first confirm an existing object path, or confirm a local file to upload via before probing.
Installation
Pre-check: Aliyun CLI >= 3.3.3 required
Run
to verify >= 3.3.3. If not installed or version too low,
see
references/cli-installation-guide.md
for installation instructions.
Then run the credential gate
.
Only after shows a valid profile, run
aliyun configure set --auto-plugin-install true
and
.
Run the version and credential gate first:
bash
aliyun version
aliyun configure list
Only after
confirms a valid profile, proceed:
bash
aliyun configure set --auto-plugin-install true
aliyun configure ai-mode enable
aliyun ossutil version
AI safety mode:
activates the CLI's built-in safety guard, which blocks dangerous operations (e.g. deleting critical resources) at the CLI level. This must be enabled before executing any ossutil commands.
Environment Variables
| Environment Variable | Required/Optional | Description | Default Value |
|---|
| Optional | Specify which CLI profile to use | Current default profile |
| Optional | HTTP proxy address in proxied environments | None |
| Optional | HTTPS proxy address in proxied environments | None |
| Optional | Proxy bypass list | None |
Parameter Confirmation
IMPORTANT: Parameter Confirmation — Before executing any command or API call,
ALL user-customizable parameters (e.g., RegionId, instance names, CIDR blocks,
passwords, domain names, resource specifications, etc.) MUST be confirmed with the
user. Do NOT assume or use default values without explicit user approval.
| Parameter Name | Required/Optional | Description | Default Value |
|---|
| Optional | CLI profile to use | Current default profile |
| Optional | Region where the bucket is located; use when auto-detection is unreliable or explicit specification is needed | None |
| Required for bucket-based probes | Target bucket name | None |
| Required for and ; optional for other bucket-based probes | Full object path, e.g. ; for , objects larger than 5 MiB are recommended for stable results | None |
| Optional | Local upload file path, symlink scan directory, or download save path | None |
| Required for URL-based download probe | Public-read URL or signed private URL | None |
| Optional | Use only when the user explicitly provides it or the error message clearly points to a specific endpoint | None |
| Optional | Domain for network connectivity check | only if user explicitly accepts |
| Optional | Upload probe mode | |
| Optional | Max runtime in seconds for / | CLI default |
| Optional | Single-file concurrency for | |
| Optional | Part size in bytes for | CLI auto/default |
Authentication
Pre-check: Alibaba Cloud Credentials Required
Security Rules:
- NEVER read, echo, or print AK/SK values (e.g.,
echo $ALIBABA_CLOUD_ACCESS_KEY_ID
is FORBIDDEN)
- NEVER ask the user to input AK/SK directly in the conversation or command line
- NEVER use with literal credential values
- NEVER read credential files such as , or dump environment variables to inspect credentials
- NEVER write a full presigned URL with query-string signature parameters into logs or final output; if you must mention it, redact everything after
- ONLY use to check credential status
Check the output for a valid profile (AK, STS, or OAuth identity).
If no valid profile exists, STOP here.
- Obtain credentials from Alibaba Cloud Console
- Configure credentials outside of this session (via in terminal or environment variables in shell profile)
- Return and re-run after shows a valid profile
If multiple profiles exist, explicitly add
in subsequent commands, placed after
and before
, e.g.
aliyun --profile <profile> ossutil version
.
RAM Policy
The minimum OSS permissions required by this skill depend on the probe mode. Refer to
references/ram-polices.md
for per-scenario permission tables and policy examples.
- Upload probes, upload bandwidth probes, temporary object probes: require at least , ,
- Download probes, download bandwidth probes, download time probes: require at least
- If using to pre-upload a test object: requires
- If using to clean up an explicitly specified test object: requires
Core Workflow
1. Validate the CLI environment
Execute in the following order — do not skip steps:
- Check CLI version first:
- Then check credentials/profile:
- If does not show a valid profile, or reports a missing config file, STOP immediately.
- Do NOT proceed with
configure set --auto-plugin-install true
- Do NOT proceed with
- Do NOT fabricate bucket, object, profile, region, or probe success results
- Only after the profile is valid, proceed to prepare the plugin, enable AI safety mode, and verify :
bash
aliyun configure set --auto-plugin-install true
aliyun configure ai-mode enable
aliyun ossutil version
1.1 Log file naming and command substitution
- When saving execution logs, use static strings for filenames (e.g. ). Do not use , , or backtick shell command substitutions in filenames, because different execution environments have inconsistent shell interpolation support, which can easily cause syntax errors.
- Some execution environments block command substitution entirely. When you need to capture command output into a variable (e.g. for presigned URLs), use the file+script pattern: redirect output to a temporary file, then create a shell script that reads the file and uses the value. See §B for a concrete example.
2. Choose the probe mode
A. Upload connectivity probe
- If the user only wants network/upload connectivity diagnostics without keeping the object, omit and and let use a temporary file that is auto-cleaned after completion.
- If the user wants to verify a specific real file's upload path, confirm .
- If the upload probe returns , quote the error as-is and explain that at least , , are required; do not enumerate buckets, regions, or fall back to legacy command forms.
bash
aliyun ossutil probe \
--upload "<LOCAL_PATH_IF_ANY>" \
--bucket "<BUCKET_NAME>" \
--object "<OBJECT_NAME_IF_USER_WANTS_TO_KEEP_IT>" \
--addr "<ADDR_IF_CONFIRMED>" \
--upmode "<UPMODE_IF_CONFIRMED>" \
--region "<REGION_ID_IF_NEEDED>" \
--user-agent AlibabaCloud-Agent-Skills
When
is not provided, remove that positional parameter entirely — do not pass an empty string.
B. Download probe via URL
- Public-read objects: have the user confirm a directly accessible URL.
- Private objects: generate a presigned URL first, then run .
Generate a presigned URL, save it to a temporary file, then run the probe via a shell script. This two-step approach avoids exposing the full URL in command history and works in environments where
command substitution is blocked.
Step 1 — Generate the presigned URL and redirect output to a temporary file:
bash
aliyun ossutil presign \
"oss://<BUCKET_NAME>/<OBJECT_NAME>" \
--expires-duration 1h \
--region "<REGION_ID_IF_NEEDED>" \
--user-agent AlibabaCloud-Agent-Skills > /tmp/_presign_url.txt
Step 2 — Create a probe script that reads the URL from the file and runs the download probe:
bash
cat > /tmp/_run_presign_probe.sh << 'PROBE_SCRIPT'
#!/bin/bash
PRESIGN_URL=$(cat /tmp/_presign_url.txt)
aliyun ossutil probe \
--download \
--url "$PRESIGN_URL" \
"<LOCAL_PATH_IF_USER_WANTS_TO_RENAME>" \
--user-agent AlibabaCloud-Agent-Skills
PROBE_SCRIPT
bash /tmp/_run_presign_probe.sh
Important — you MUST use with the presigned URL:
- Never copy-paste the full presigned URL directly into the parameter — use the file+script pattern above so the URL is never exposed in command history or execution logs.
- If is not writable, use the current workspace directory for the temporary file and script instead.
only accepts HTTP/HTTPS URLs — it cannot take
.
- A successful only means the signed URL was generated; it does not guarantee the bucket or object exists, nor that the subsequent download will succeed.
- If you need to log the execution, do not persist the full presigned URL; at most keep the object address without the query string, or redact all signature parameters after .
- If returns 404/403, quote the raw HTTP error first; if the bucket/object was already confirmed input, you may do one validation with the same . Do not try to "guess" the root cause by listing buckets, trying random regions, or reading local credential files.
C. Download probe via Bucket/Object
- If the user confirmed , the command will download that object directly.
- If the user does not provide , will create a temporary object, download it, and delete the temporary object after completion.
bash
aliyun ossutil probe \
--download \
--bucket "<BUCKET_NAME>" \
--object "<OBJECT_NAME_IF_ANY>" \
--addr "<ADDR_IF_CONFIRMED>" \
"<LOCAL_PATH_IF_USER_WANTS_TO_RENAME>" \
--region "<REGION_ID_IF_NEEDED>" \
--user-agent AlibabaCloud-Agent-Skills
- If the command reports , , or other object-level errors, prefer running
ossutil stat "oss://<BUCKET_NAME>/<OBJECT_NAME>" --region "<REGION_ID_IF_NEEDED>"
for same-target validation.
- Do not list all buckets, try unconfirmed regions, or switch to / or other commands outside this skill's scope to confirm whether the object exists.
D. Local symlink anomaly probe
This mode only checks local directory/file paths — it does not access OSS.
bash
aliyun ossutil probe \
--probe-item cycle-symlink \
"<LOCAL_DIRECTORY_OR_FILE>" \
--user-agent AlibabaCloud-Agent-Skills
-
If the command returns
stat <path>: no such file or directory
, explicitly state that the local path does not exist in the current execution environment; this is still a local-only flow with no OSS access.
-
When the local path does not exist, you must NEVER:
- Interpret it as "this is a containerized/sandbox environment limitation"
- Automatically rewrite it as "the user should run on another machine/production environment"
- Generate a script file saying "run this command in the correct environment"
- Check the parent directory with and then give up
Correct approach: Quote the raw error
stat <path>: no such file or directory
, explicitly tell the user the path does not exist in the current environment, and ask whether they provided the correct path. Unless the user proactively states the current session is not on the target machine, do not make that judgment for them.
When reporting results of this probe, include at minimum:
- This is a local-only flow — no OSS access occurred
- Which symlinks are abnormal and which link chains were directly verified; if only partial chains can be verified, clearly distinguish "confirmed chain segments" from "anomaly points proven by probe errors", e.g. , and resolving reports
too many levels of symbolic links
- If the probe output contains raw errors, quote at least one key error, e.g.
too many levels of symbolic links
- Minimum fix prerequisites, e.g. break one of the cyclic links or re-point the abnormal link to a real target before retrying
If you need to clarify the abnormal link chain, you may perform read-only local forensics on the same path (e.g.
,
). Only write precise chains when these supplementary results are actually readable; if the supplementary forensics itself fails, report only verified segments — do not fabricate a complete cycle.
If the output lists abnormal symlinks, the user or a local script must fix them according to business semantics; this skill does not auto-rewrite symlink targets.
E. Upload bandwidth probe with suggested concurrency
Basic command:
bash
aliyun ossutil probe \
--probe-item upload-speed \
--bucket "<BUCKET_NAME>" \
--region "<REGION_ID_IF_NEEDED>" \
--user-agent AlibabaCloud-Agent-Skills
To limit runtime, add:
bash
aliyun ossutil probe \
--probe-item upload-speed \
--bucket "<BUCKET_NAME>" \
--runtime "<RUNTIME_IF_CONFIRMED>" \
--region "<REGION_ID_IF_NEEDED>" \
--user-agent AlibabaCloud-Agent-Skills
Successful output will contain
.
F. Download bandwidth probe with suggested concurrency
- is required.
- Official recommendation: target object should be larger than 5 MiB.
- If the user has no suitable object, first confirm a local file path, then upload a cleanable test object via .
Optional preparation step:
bash
aliyun ossutil cp \
"<LOCAL_FILE_TO_UPLOAD>" \
"oss://<BUCKET_NAME>/<OBJECT_NAME>" \
--region "<REGION_ID_IF_NEEDED>" \
--user-agent AlibabaCloud-Agent-Skills
Run download bandwidth probe:
bash
aliyun ossutil probe \
--probe-item download-speed \
--bucket "<BUCKET_NAME>" \
--object "<OBJECT_NAME>" \
--runtime "<RUNTIME_IF_CONFIRMED>" \
--region "<REGION_ID_IF_NEEDED>" \
--user-agent AlibabaCloud-Agent-Skills
G. Download time probe
Basic command:
bash
aliyun ossutil probe \
--probe-item download-time \
--bucket "<BUCKET_NAME>" \
--object "<OBJECT_NAME>" \
--region "<REGION_ID_IF_NEEDED>" \
--user-agent AlibabaCloud-Agent-Skills
To explicitly control concurrency and part size, add:
bash
aliyun ossutil probe \
--probe-item download-time \
--bucket "<BUCKET_NAME>" \
--object "<OBJECT_NAME>" \
--parallel "<PARALLEL_IF_CONFIRMED>" \
--part-size "<PART_SIZE_IF_CONFIRMED>" \
--region "<REGION_ID_IF_NEEDED>" \
--user-agent AlibabaCloud-Agent-Skills
and
are only meaningful in the
scenario; do not misuse them with
.
3. Interpret the output
- When upload/download probes succeed, the output will contain or
- When bandwidth probes succeed, the output will contain multiple statistics and
- When download time probes succeed, the output will contain , ,
- All probe modes typically generate a local log file; after probe execution, you must check whether was generated in the current directory and report the log path in the final answer
- If a real command returns an error or has no success marker, the final conclusion must explicitly state failure/blocked and quote the raw error message — do not write "task completed successfully" or describe a failure as successful verification
- When a command fails, the final answer must explicitly state the termination reason (e.g. "stopped due to AccessDenied", "stopped due to path not found") — do not end silently
- For errors like
The bucket you are attempting to access must be addressed using the specified endpoint
, this only means the current access endpoint does not match the bucket's requirements; stop immediately, ask the user to confirm the correct region/endpoint — do not infer or try other region/endpoints on your own
See
references/verification-method.md
for more detailed verification steps.
Success Verification Method
Follow the steps in
references/verification-method.md
to confirm each item:
- CLI version and profile are valid
- Probe output contains success markers or suggested concurrency
- You must run to check whether log files were generated locally, and report the log path in the final answer; if no log files were generated, it means the probe may not have reached the actual probing stage
- If an explicit test object was used, confirm whether it should be retained or enter the cleanup step
- If any of the above steps fail, the final answer must explicitly state failure and quote the raw error with termination reason
Cleanup
- Upload/download connectivity probes without an explicit will auto-clean temporary objects
- If you explicitly uploaded a test object in the preparation step, decide whether to delete it based on user confirmation after probing
Delete an OSS test object:
bash
aliyun ossutil rm \
"oss://<BUCKET_NAME>/<OBJECT_NAME>" \
--user-agent AlibabaCloud-Agent-Skills
If a temporary test file was downloaded locally, it should also be deleted or retained based on user confirmation.
After all probe and cleanup steps are finished, disable AI safety mode:
bash
aliyun configure ai-mode disable
API and Command Tables
For all commands, underlying OSS capability mappings, and which steps are local client-side logic only, see
references/related-apis.md
.
Best Practices
- Always use — do not fabricate non-existent commands like
- Confirm all user-variable parameters before execution, especially , , ,
- Only retain probe objects when the user explicitly confirms; otherwise prefer temporary objects or explicit cleanup
- For , choose a real object larger than 5 MiB for more stable results
- In proxy, dedicated line, or custom domain scenarios, explicitly confirm , ,
- Use as an empirical baseline, then do small-scale validation combined with actual business concurrency
- For , only diagnose — do not auto-fix
- After command failure, prefer same-target validation (e.g. ) — do not expand into listing buckets, guessing regions, trying unsupported flags, or reading local credential files
- Do not expose AK/SK, STS tokens, or full presigned URL query strings in logs or final results
- A successful presign, resolvable DNS, or reachable ping/traceroute does not guarantee the object exists or that the probe will succeed; conclusions must be based on actual probe/validation results
Reference Links
| Reference | Purpose |
|---|
references/cli-installation-guide.md
| Installing and upgrading Aliyun CLI |
references/verification-method.md
| Checking success by probe mode |
references/related-apis.md
| Command to underlying OSS capability/permission mapping |
references/ram-polices.md
| RAM permission checklist and policy examples |
references/acceptance-criteria.md
| Skill acceptance criteria and counter-examples |
references/implementation-boundaries.md
| Boundaries that cannot be fully automated via CLI or code |