crazy-max_diun/docs/faq.md

FAQ

Timezone

By default, all interpretation and scheduling is done with your local timezone (TZ environment variable).

Cron schedule may also override the timezone to be interpreted in by providing an additional space-separated field at the beginning of the cron spec, of the form CRON_TZ=<timezone>:

watch:
  schedule: "CRON_TZ=Asia/Tokyo 0 */6 * * *"

Test notifications

Through the command line with:

diun --config ./diun.yml --test-notif

Or within a container:

docker-compose exec diun diun --test-notif

field docker|swarm uses unsupported type: invalid

If you have the error failed to decode configuration from file: field docker uses unsupported type: invalid that's because your docker, swarm or kubernetes provider is not initialized in your configuration:

!!! failure yaml providers: docker:

should be:

!!! success yaml providers: docker: {}

No image found in manifest list for architecture, variant, OS

If you encounter this kind of warning, you are probably using the file provider containing an image with an erroneous or empty platform. If the platform is not filled in, it will be deduced automatically from the information of your operating system on which Diun is running.

In the example below, Diun is running (diun_x.x.x_windows_i386.zip) on Windows 10 and tries to analyze the crazymax/cloudflared image with the detected platform (windows/386):

- name: crazymax/cloudflared:2020.2.1
  watch_repo: true

But this platform is not supported by this image as you can see on DockerHub:

!!! warning Fri, 27 Mar 2020 01:20:03 UTC WRN Cannot get remote manifest error="Cannot create image closer: Error choosing image instance: no image found in manifest list for architecture 386, variant \"\", OS windows" image=docker.io/image=crazymax/cloudflared:2020.2.1 provider=file

You have to force the platform for this image if you are not on a supported platform:

- name: crazymax/cloudflared:2020.2.1
  watch_repo: true
  platform:
    os: linux
    arch: amd64

!!! success Fri, 27 Mar 2020 01:24:33 UTC INF New image found image=docker.io/crazymax/cloudflared:2020.2.1 provider=file

Too many requests to registry

The error Cannot create image closer: too many requests to registry is returned when the HTTP status code returned by the registry is 429.

This can happen on the DockerHub registry because of the rate-limited anonymous pulls.

To solve this you must first be authenticated against the registry through the regopts settings:

regopts:
  - name: "docker.io"
    selector: image
    username: foo
    password: bar

If this is not enough, tweak the schedule setting with something like 0 */6 * * * (every 6 hours).

Docker Hub rate limits

Docker is now enforcing Docker Hub pull rate limits. This means you can make 100 pull image requests per six hours for anonymous usage, and 200 pull image requests per six hours for free Docker accounts. But this rate limit is not necessarily an indicator on the number of times an image has actually been downloaded. In fact, their pulls counter/metric is actually a representation of the number of times a manifest for a particular image has been retrieved.

As you probably know, Diun downloads the manifest of an image from its registry through a GET request to be able to retrieve its inside metadata. Fortunately Diun doesn't perform a GET request at each scan but only when an image has been updated or added on the registry. This allows us not to exceed this rate limit in our situation, but it also strongly depends on the number of images you scan. To increase your pull rate limits you can upgrade your account to a Docker Pro or Team subscription and authenticate against the registry through the regopts settings:

regopts:
  - name: "docker.io"
    selector: image
    username: foo
    password: bar

Or you can tweak the schedule setting with something like 0 */6 * * * (every 6 hours).

Profiling

Diun provides a simple way to manage runtime/pprof profiling through --profiler-path and --profiler flags:

version: "3.5"

services:
  diun:
    image: crazymax/diun:latest
    volumes:
      - "./data:/data"
      - "./profiler:/profiler"
      - "/var/run/docker.sock:/var/run/docker.sock"
    environment:
      - "TZ=Europe/Paris"
      - "LOG_LEVEL=info"
      - "PROFILER_PATH=/profiler"
      - "PROFILER=mem"
      - "DIUN_PROVIDERS_DOCKER=true"
    restart: always

Following profilers are available:

• cpu enables cpu profiling
• mem enables memory profiling
• alloc enables memory profiling and changes which type of memory to profile allocations
• heap enables memory profiling and changes which type of memory profiling to profile the heap
• routines enables goroutine profiling
• mutex enables mutex profiling
• threads enables thread creation profiling
• block enables block (contention) profiling