How to fix OCI runtime create failed: container_linux.go: starting container process caused: exec: "/bin/bash": stat /bin/bash: no such file or directory in Docker

# Instead of this (fails on Alpine/minimal images):
docker exec -it mycontainer /bin/bash

# Use this:
docker exec -it mycontainer /bin/sh

docker exec -it mycontainer /bin/ash

docker run --rm -it myimage ls -la /bin/*sh*

# Before (fails on Alpine):
CMD ["/bin/bash", "-c", "echo hello"]
ENTRYPOINT ["/bin/bash", "/entrypoint.sh"]

# After (works on all images with a shell):
CMD ["/bin/sh", "-c", "echo hello"]
ENTRYPOINT ["/bin/sh", "/entrypoint.sh"]

# Before:
#!/bin/bash

# After (POSIX-compatible):
#!/bin/sh

FROM alpine:latest

# Install bash
RUN apk add --no-cache bash

# Now you can use /bin/bash
CMD ["/bin/bash"]

# First, rebuild the image with bash installed
docker build -t myimage:with-bash .

# Then you can exec with bash
docker exec -it mycontainer /bin/bash

docker exec -it mycontainer /bin/sh -c "apk add --no-cache bash && /bin/bash"

# Google's distroless images have debug tags with busybox shell
docker run -it --entrypoint /busybox/sh gcr.io/distroless/base:debug

# Build stage
FROM golang:1.21 AS builder
WORKDIR /app
COPY . .
RUN CGO_ENABLED=0 go build -o myapp

# Runtime stage - no shell available
FROM scratch
COPY --from=builder /app/myapp /myapp
# Must use exec form (JSON array) - shell form won't work
ENTRYPOINT ["/myapp"]

# Copy files out for inspection
docker cp mycontainer:/app/logs ./logs

# Or use docker debug (Docker Desktop 4.27+)
docker debug mycontainer

# Shell form - requires /bin/sh to parse the command (will fail on scratch)
CMD echo "hello"
ENTRYPOINT /app/start.sh

# Exec form - runs directly without a shell (works on any image)
CMD ["echo", "hello"]
ENTRYPOINT ["/app/start.sh"]

# Runs: /app/myapp with arguments from CMD
ENTRYPOINT ["/app/myapp"]
CMD ["--config", "/etc/app/config.yaml"]

# List all shell-like binaries
docker run --rm myimage ls -la /bin/ 2>/dev/null | grep -E 'sh|bash|ash|zsh'

# Check if specific shell exists
docker run --rm myimage which sh
docker run --rm myimage which bash

# Inspect the image's default shell
docker inspect --format='{{.Config.Shell}}' myimage