I've been evaluating Snyk for container vulnerability scanning as part of our CI pipeline pre-deployment checks. The GUI-based scanning via the Snyk UI works, but we need to integrate this into our automated, air-gapped build system, which means relying on the CLI. This is where things are falling apart, and the failure mode is utterly useless: silent exits with a zero code, producing no output and no scan results.
Here is the exact command sequence I'm running, following the official documentation. We're using the latest `snyk` CLI version 1.1252.0.
```bash
# First, authenticate with a service account token (sensitive part redacted)
snyk auth
# Confirmation: Authentication successful.
# Load a locally built image tagged as myapp:test
docker load -i myapp.tar
# Attempt to scan the local image
snyk container test myapp:test --file=Dockerfile.prod
```
The command executes, appears to think for a moment, and then simply returns to the prompt. No success message, no vulnerability report, no error. Exit code is 0. This is worse than a clear failure because it's passing in our automation scripts, giving a false sense of security. I've tried several permutations:
* `snyk container test myapp:test` (without `--file`)
* `snyk test --docker myapp:test` (the older syntax)
* Using the `--debug` flag, which adds some logs but stops short of revealing the root cause. The last debug lines show HTTP activity, then nothing.
* Increasing verbosity with `-d`. No additional clues.
My environment is a hardened RHEL 8 build server. The image is based on `redhat/ubi8:8.9`. I suspect the issue may be one of the following, but the CLI's behavior makes diagnosis impossible:
1. A network egress issue to Snyk's APIs, even though the image is local and we have a vendor-approved internet proxy. The `--debug` output shows successful API calls for authentication and policy lookup.
2. A permissions problem with the local Docker daemon or the image layers.
3. Some incompatibility with the specific base image or a non-standard filesystem layout inside the container.
What I need is a way to force the CLI to actually tell me what's wrong. Has anyone else hit this wall of silence with local image scanning? Specifically:
* Are there known issues with scanning UBI-based images or images built without a visible `FROM` layer in the history?
* Is there a hidden log file or a more granular debug level than `--debug`?
* Has anyone crafted a working command sequence for a truly offline-first scan, where the CLI only needs the internet for the initial auth and policy fetch?
The documentation assumes everything works. It doesn't. I need the operational reality. If the CLI cannot reliably scan a local image and report actionable errors, then it's a non-starter for our pipeline, regardless of the quality of the vulnerability database.
Ah, the classic silent exit with a zero. I've seen that ghost before, and it usually means the CLI is hitting some internal timeout or a missing dependency it just won't admit to. The fact that the GUI scan works suggests the API's fine, so the problem's likely local.
Have you tried running it with `--debug` or `-d`? Sometimes that pries loose a log that points at a missing Docker socket permission or a network proxy it's trying to use for some reason, even for a local image. Also, check if your `myapp:test` image has any weird, multi-platform manifests that might confuse its layer analysis.
Data over dogma.
That silent exit with a zero is maddening - been there with other CLI tools. One thing to double-check: is your Snyk CLI configured for the correct organization? It can auth successfully but then try to report to an org it can't reach, especially in an air-gapped setup, and just... give up quietly.
Also, have you tried running it without the `--file` flag at all? Sometimes that flag introduces a different parsing path that can choke and exit cleanly when it hits something unexpected in your Dockerfile, like a multi-stage build where the final image tag isn't obvious. The GUI might handle that gracefully where the CLI doesn't.
That's a really good point about the org configuration. I hadn't considered that auth success doesn't mean the CLI knows where to send results in an air-gapped environment.
> is your Snyk CLI configured for the correct organization?
How would you even check that from the CLI? Is there a `snyk config` command or an env var it uses? If it defaults to some global org and can't reach it, the silent exit makes a bit more sense, even if it's unhelpful.
The multi-stage build angle is interesting too. Our Dockerfile does have multiple stages. The GUI scan probably just analyzes the final image, but maybe the CLI with `--file` gets lost trying to trace the build steps. I'll try the scan without the flag first and see what happens. Thanks for the ideas!
You can check the configured organization with `snyk config get org`. The CLI uses that stored value for all subsequent commands. In an air-gapped context, if that org endpoint is unreachable, a silent failure is plausible.
Regarding multi-stage builds, scanning without the `--file` flag is the correct first step. However, there's a nuance: the CLI might still fail silently if the final stage doesn't have an explicit `LABEL` or if it uses a non-standard base image the scanner can't resolve locally. The GUI often has more forgiving fallback logic for parsing the image metadata.
Migrate slow, validate fast.