Error map
unhealthy Docker container is unhealthy (health check failing)
Docker · layer 6, Platform & cloud
Centre: this error. First ring: errors it is linked with (12). Outer ring: what those are linked with. Colours show the layer of a request each error belongs to. Click any dot to re-centre the map on it; hover to follow its connections. The centre dot opens the error page.
Directly related (12)
Error response from daemon: Pool overlaps with other one on this address space
Docker tried to create a network whose subnet clashes with an existing Docker network (or a VPN/host route).
docker-compose: command not found / 'compose' is not a docker command
Your system has only one of the two Compose flavours: the old docker-compose (v1) binary or the newer docker compose (v2) plugin.
docker compose: services.x Additional property y is not allowed / yaml: line N: mapping values are not allowed
The compose file is invalid YAML or uses a key Compose doesn’t recognise at that level (usually an indentation mistake).
Error response from daemon: Container X is not running
You tried to exec into or interact with a container that has stopped.
Liveness probe failed ... Container will be restarted (also Startup probe failed)
The kubelet’s liveness (or startup) check failed enough times that it killed and restarted the container.
Readiness probe failed: HTTP probe failed with statuscode: 503 / connect: connection refused
The container is running, but its readiness check fails, so the pod is marked not ready and removed from Service endpoints.
Cloud Run: The user-provided container failed to start and listen on the port defined provided by the PORT=8080 environment variable
Cloud Run started your container, but nothing listened on $PORT within the startup timeout — the app crashed, listens on another…
service "web" depends on undefined service "db": invalid compose project
A service lists depends_on (or links/networks) for a service name that isn’t defined in the Compose file(s) being used.
Azure Container Registry: unauthorized: authentication required, visit https://aka.ms/acr/authorization (AKS ErrImagePull 401)
Pulling/pushing to ACR wasn’t authenticated — Docker not logged in, or AKS/App Service lacks AcrPull on the registry.
Conflict. The container name "/x" is already in use by container …
A container (running or stopped) already has that name; Docker won’t create a second one with the same name.
WARN: the attribute `version` is obsolete, it will be ignored
A harmless Compose v2 warning: the top-level version: line in docker-compose.yml is no longer used.
ALB target unhealthy: Health checks failed with these codes: [404] / Request timed out
The load balancer’s health checks to your targets fail, so it stops sending traffic (and returns 502/503 if no targets are health…
Two steps away (36)
Error response from daemon: network X not found
The container or Compose project refers to a Docker network that doesn’t exist (any more).
driver failed programming external connectivity on endpoint: iptables: No chain/target/match by that name
Docker’s iptables rules were wiped (firewalld/ufw reload, iptables flush) while Docker was running, so it can’t publish ports.
android.os.NetworkOnMainThreadException
The app made a network call on the main (UI) thread, which Android forbids.
fatal: not a git repository (or any of the parent directories): .git
You ran a Git command outside a Git working tree.
bash: command not found
The shell can’t find an executable with that name in any directory on your PATH.
ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
Build tools (Gradle, Maven, Android tools) can’t find a JDK.
IndentationError: unexpected indent / expected an indented block
Python’s block structure is broken — inconsistent indentation or mixed tabs and spaces.
COPY failed: file not found in build context / "/app/x": not found
The Dockerfile COPY refers to a path outside the build context, excluded by .dockerignore, or relative to the wrong directory.
error converting YAML to JSON: yaml: line 12: did not find expected key
The manifest isn’t valid YAML — usually indentation, a tab character, or an unquoted special character.
Docker: Bind for 0.0.0.0:80 failed: port is already allocated
Another container or host process already publishes that host port.
ECS task stopped: CannotPullContainerError: pull image manifest has been retried ... / ref pull has been retried
The ECS task couldn’t pull its image — no network route to the registry, missing ECR permissions, or a wrong image tag.
ECS: Essential container in task exited (task keeps stopping)
The main (essential) container stopped, so ECS stopped the whole task and the service keeps replacing it.
Kubernetes: CrashLoopBackOff
The container starts, crashes (or exits), and Kubernetes keeps restarting it with increasing back-off delays.
Kubernetes: OOMKilled (exit code 137)
The container used more memory than its limit, and the kernel killed it.
Error from server (BadRequest): container "x" in pod "y" is waiting to start: ContainerCreating
kubectl logs has nothing to show yet — the container hasn’t started (still creating, pulling, or blocked).
Service has no endpoints (no endpoints available for service / Endpoints: <none>)
The Service’s selector matches no ready pods, so traffic to it is refused or returns 503.
deployment "x" exceeded its progress deadline (ProgressDeadlineExceeded)
A rollout didn’t make progress within progressDeadlineSeconds (default 600) — new pods never became ready.
Error from server: admission webhook "validate.nginx.ingress.kubernetes.io" denied the request
A validating admission webhook (ingress-nginx, Gatekeeper/OPA, Kyverno) inspected your object and rejected it; the reason follows…
exec /usr/local/bin/docker-entrypoint.sh: exec format error
The container tried to run a binary built for a different CPU architecture (arm64 vs amd64) — or a script with a broken shebang /…
npm ERR! code EROFS — EROFS: read-only file system
npm tried to write to a read-only location (read-only container filesystem, mounted volume, or system path).
OCI runtime create failed: exec: "x": executable file not found in $PATH
The command you asked the container to run doesn’t exist inside the image — wrong command name, a shell that isn’t installed (bas…
strict decoding error: unknown field "spec.template.spec.containers[0].ports[0].protocl"
The manifest contains a field the API schema doesn’t know — a typo, wrong indentation, or a field from another API version.
GitLab CI: Found errors in your .gitlab-ci.yml: jobs:build config contains unknown keys: scripts
GitLab rejected the pipeline configuration, so no pipeline was created — the message names the job and the problem.
CircleCI: Error calling workflow: 'build'. Cannot find a definition for job named test / Config does not conform to schema
CircleCI could not compile `.circleci/config.yml` — a workflow refers to a missing job, a key is invalid, or the YAML is malforme…
Kubernetes: ImagePullBackOff / ErrImagePull
The node can’t pull the container image — wrong name/tag, missing registry credentials, or registry unreachable.
denied: Your authorization token has expired. Reauthenticate and try again. (Amazon ECR)
Docker’s login to Amazon ECR has expired — ECR tokens last 12 hours, so pushes and pulls fail until you log in again.
unauthorized: authentication required (docker push / pull)
The registry needs credentials for this operation and the request had none or had expired ones.
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
The docker CLI can’t talk to the Docker engine — it isn’t running, or your user can’t access the socket.
exec /docker-entrypoint.sh: no such file or directory (CRLF line endings / missing interpreter)
The entrypoint file exists, but the kernel can’t run it — almost always Windows CRLF line endings in the script, or a shebang poi…
Docker container exits immediately (Exited (0) / Exited (1) right after start)
The container started and its main process finished at once, so the container stopped — Docker containers only live as long as PI…
DeprecationWarning: Buffer() is deprecated due to security and usability issues (DEP0005)
Code (yours or a dependency) uses the deprecated new Buffer() constructor.
DeprecationWarning: The `punycode` module is deprecated (DEP0040)
A dependency imports Node’s built-in punycode module, deprecated since Node 21.
npm WARN deprecated package@1.2.3: This package is no longer supported.
A dependency (often a transitive one) is deprecated by its author.
HTTP 502 Bad Gateway
A proxy or gateway (Nginx, load balancer, CDN) got an invalid response — or no response — from the upstream server behind it.
HTTP 503 Service Unavailable
The server is temporarily unable to handle the request — overloaded, in maintenance, or has no healthy backends.
AccessDeniedException: User: arn:aws:iam::... is not authorized to perform: service:Action on resource: ...
The IAM user or role making the call has no permission for that action on that resource — the message names both.
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