`Cannot connect to the Docker daemon` when calling `docker run` inside a local action

[jameshounshell]

Bug report info

act version:            0.2.75
GOOS:                   darwin
GOARCH:                 arm64
NumCPU:                 12
Docker host:            unix:///Users/jameshounshell/.config/colima/default/docker.sock
Sockets found:
Config files:
        /Users/jameshounshell/.config/act/actrc:
                -P ubuntu-latest=catthehacker/ubuntu:act-latest
                -P ubuntu-22.04=catthehacker/ubuntu:act-22.04
                -P ubuntu-20.04=catthehacker/ubuntu:act-20.04
                -P ubuntu-18.04=catthehacker/ubuntu:act-18.04
Build info:
        Go version:            go1.24.0
        Module path:           command-line-arguments
        Main version:
        Main path:
        Main checksum:
        Build settings:
                -buildmode:           exe
                -compiler:            gc
                -ldflags:             -X main.version=0.2.75
                DefaultGODEBUG:       gotestjsonbuildtext=1,multipathtcp=0,randseednop=0,rsa1024min=0,tlsmlkem=0,x509rsacrt=0,x509usepolicies=0
                CGO_ENABLED:          1
                CGO_CFLAGS:
                CGO_CPPFLAGS:
                CGO_CXXFLAGS:
                CGO_LDFLAGS:
                GOARCH:               arm64
                GOOS:                 darwin
                GOARM64:              v8.0
Docker Engine:
        Engine version:        27.4.0
        Engine runtime:        runc
        Cgroup version:        2
        Cgroup driver:         cgroupfs
        Storage driver:        overlay2
        Registry URI:          https://index.docker.io/v1/
        OS:                    Ubuntu 24.04.1 LTS
        OS type:               linux
        OS version:            24.04
        OS arch:               x86_64
        OS kernel:             6.8.0-50-generic
        OS CPU:                2
        OS memory:             1963 MB
        Security options:
                name=apparmor
                name=seccomp,profile=builtin
                name=cgroupns

Command used with act

act \
workflow_dispatch \
-W ./.github/workflows/_test_local.yaml \
-P self-hosted=catthehacker/ubuntu:act-latest  # works with `-self-hosted` on m2 mac

Describe issue

We use an action (composite type, not docker type) to run a little bit of shell then execute a docker run ... command. It appears that the act-latest docker-in-docker is not available to code running inside an action. This is allowed in real Github actions.

Interestingly (but maybe obviously/expectedly?) docker run within the action works fine if I use the -P self-hosted=-self-hosted to run on the mac directly. Also I do set DOCKER_HOST already and even if I try to export it inside the action itself, the socket is not actually there.

I know this is an edge case because you'd probably expect a docker type action with the container that has my dependencies. (for reference the actual image used is registry.k8s.io/kustomize/kustomize:v5.4.2 which I was too lazy to build a custom image for.)

Here's the setup: .github/workflows/_test_local.yaml --calls--> ./.github/actions/my-action --runs--> docker run ...

.github/workflows/_test_local.yaml

name: local testing
on:
  workflow_dispatch:

jobs:
  main:
    runs-on: self-hosted
    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          path: "."  # for local development with ACT you must do this!!!
      - name: update
        uses: ./.github/actions/my-action
        with:
          name: James

./.github/actions/my-action/action.yaml

name: 'hello'
description: 'hello'
inputs:
  name:
    required: true
    type: string
    description: 'your name'
runs:
  using: "composite"
  steps:
    - id: hello
      shell: bash
      run: |
          docker run \
            -v $(pwd):/tmp \
            --workdir /tmp/
            alpine "echo hello ${{inputs.name}}"

Link to GitHub repository

No response

Workflow content

# see description for workflow content

Relevant log output

docker run \
  -v $(pwd):/tmp \
  --workdir /tmp/
  alpine "echo hello James"

[local testing/step1]   🐳  docker exec cmd=[bash --noprofile --norc -e -o pipefail /var/run/act/workflow/1-composite-hello.sh] user= workdir=
| docker host:
| docker: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
|
| Run 'docker run --help' for more information