EC
Exit Code 127
DockerERRORCriticalStartupHIGH confidence

Contained command not found

What this means

Exit code 127 indicates that the command specified as the container's CMD or ENTRYPOINT could not be found within the container's PATH. This is a common error caused by a missing dependency, a typo in a command, or an incorrect PATH environment variable.

Why it happens
  1. 1The specified command is not installed in the base image.
  2. 2There is a typo in the CMD or ENTRYPOINT instruction in the Dockerfile.
  3. 3The command is located in a directory that is not included in the system's PATH variable.
  4. 4The script is using Windows-style line endings (CRLF) which confuses Linux shells.
How to reproduce

A Dockerfile's ENTRYPOINT refers to 'node' but the base image is 'alpine', which does not include Node.js by default.

trigger — this will error
trigger — this will error
# Dockerfile
FROM alpine:latest
WORKDIR /app
COPY . .
# 'node' command does not exist in the 'alpine' base image
ENTRYPOINT ["node", "app.js"]

expected output

OCI runtime create failed: container_linux.go:380: starting container process caused: exec: "node": executable file not found in $PATH: unknown

Fix 1

Install the Missing Dependency

WHEN The command is a required package that isn't in the base image.

Install the Missing Dependency
# Dockerfile for Debian/Ubuntu
FROM ubuntu
RUN apt-get update && apt-get install -y nodejs
...

# Dockerfile for Alpine
FROM alpine
RUN apk add --no-cache nodejs
...

Why this works

This adds a layer to the image that downloads and installs the required program, making it available in the PATH.

Fix 2

Use an Official Base Image

WHEN You are building an image for a standard application like Node.js, Python, etc.

Use an Official Base Image
# Use the official Node.js image instead of a generic one
FROM node:18-alpine
WORKDIR /app
COPY . .
CMD ["node", "app.js"]

Why this works

Official images come pre-configured with the necessary runtime, dependencies, and PATH settings, which is more reliable and efficient than building it yourself.

Fix 3

Correct the Command or Path

WHEN The command is misspelled or located in a non-standard directory.

Correct the Command or Path
# If command is at /opt/my-app/run.sh
ENTRYPOINT ["/opt/my-app/run.sh"]

Why this works

Using an absolute path to the executable ensures it can be found regardless of the PATH environment variable's configuration.

What not to do

✕ Copy binaries from your host machine directly into the image.

This often leads to glibc/musl incompatibilities and missing linked libraries. Always install dependencies using the image's native package manager.

Sources
Official documentation ↗

Bash Manual - Exit Status

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