docker compose panics with volume override

[chrisbecke]

Description

When generating compose files for local, and cloud, deployments, different volume drivers need to be specified for the different cloud contexts. Using multiple --file directives to merge compose files seems a convenient way to support this scenario, however this causes docker compose up to throw a panic trying to merge the volume sections.

Steps to reproduce the issue:

docker-compose.yml

version: "3.9"
volumes:
  data:
services:
  cloud-test:
    image: nginx:latest
    volumes:
    - data:/data
    ports:
    - 80:80

docker-compose.azure.yml

version: "3.9"
volumes:
  data:
    driver: azure_file
    driver_opts:
      share_name: test-share
      storage_account_name: my-storage-account

1. This example requires an Azure account with a configured docker context and an azure storage account.
2. Save the above files in a folder and open a terminal there.
3. Execute docker --context azure compose up --file docker-compose.yml --file docker.compose.azure.yml where azure is the name of your azure context.

Describe the results you received:

panic: reflect: reflect.Value.Set using unaddressable value
goroutine 1 [running]:
reflect.flag.mustBeAssignableSlow(0x95)
        reflect/value.go:260 +0x138
reflect.flag.mustBeAssignable(...)
        reflect/value.go:247
reflect.Value.Set(0x2cc2ea0, 0xc000744b00, 0x95, 0x2cc2ea0, 0xc000743a40, 0x15)
        reflect/value.go:1558 +0x3b
github.com/imdario/mergo.deepMerge(0x2cc2ea0, 0xc000744b00, 0x95, 0x2cc2ea0, 0xc000744aa0, 0x95, 0xc00060ee60, 0x2, 0xc00074ae20, 0x0, ...)
        github.com/imdario/mergo@v0.3.11/merge.go:104 +0x1b97
github.com/imdario/mergo.deepMerge(0x2fd7060, 0xc000744ae0, 0x99, 0x2fd7060, 0xc000744a80, 0x99, 0xc00060ee60, 0x1, 0xc00074ae20, 0x0, ...)
        github.com/imdario/mergo@v0.3.11/merge.go:93 +0x2fb9
github.com/imdario/mergo.deepMerge(0x2cc0f80, 0xc00000f6c8, 0x195, 0x2cc0f80, 0xc00000f6d0, 0x195, 0xc00060ee60, 0x0, 0xc00074ae20, 0x195, ...)
        github.com/imdario/mergo@v0.3.11/merge.go:147 +0xa5b
github.com/imdario/mergo._map(0x2a42e60, 0xc00000f6c8, 0x2a42e60, 0xc00000f6d0, 0xc00060f090, 0x1, 0x1, 0x1, 0x1)
        github.com/imdario/mergo@v0.3.11/map.go:163 +0x43e
github.com/imdario/mergo.Map(...)
        github.com/imdario/mergo@v0.3.11/map.go:133
github.com/compose-spec/compose-go/loader.mergeVolumes(...)
        github.com/compose-spec/compose-go@v0.0.0-20210106202047-687be5e0e320/loader/merge.go:259
github.com/compose-spec/compose-go/loader.merge(0xc00074c730, 0x2, 0x2, 0x1, 0x2, 0xc00074c730)
        github.com/compose-spec/compose-go@v0.0.0-20210106202047-687be5e0e320/loader/merge.go:59 +0x20d
github.com/compose-spec/compose-go/loader.Load(0x0, 0x0, 0xc00029c8c0, 0x21, 0xc000509440, 0x2, 0x2, 0xc000508ea0, 0xc00000e078, 0x1, ...)
        github.com/compose-spec/compose-go@v0.0.0-20210106202047-687be5e0e320/loader/loader.go:176 +0x379
github.com/compose-spec/compose-go/cli.ProjectFromOptions(0xc0000b2f00, 0xc0000b2f00, 0x0, 0x0)
        github.com/compose-spec/compose-go@v0.0.0-20210106202047-687be5e0e320/cli/options.go:186 +0x31f
github.com/docker/compose-cli/cli/cmd/compose.setup(0x3640b80, 0xc00028ccf0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xc00000c660, 0x2, ...)
        github.com/docker/compose-cli/cli/cmd/compose/up.go:125 +0xb4
github.com/docker/compose-cli/cli/cmd/compose.runCreateStart(0x3640b80, 0xc00028ccf0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xc00000c660, 0x2, ...)
        github.com/docker/compose-cli/cli/cmd/compose/up.go:85 +0xad
github.com/docker/compose-cli/cli/cmd/compose.upCommand.func1(0xc0003ba580, 0xc000372500, 0x0, 0x4, 0x0, 0x0)
        github.com/docker/compose-cli/cli/cmd/compose/up.go:49 +0xf1
github.com/spf13/cobra.(*Command).execute(0xc0003ba580, 0xc0003724c0, 0x4, 0x4, 0xc0003ba580, 0xc0003724c0)
        github.com/spf13/cobra@v1.1.1/command.go:850 +0x47c
github.com/spf13/cobra.(*Command).ExecuteC(0xc00002d080, 0xc00028ccc0, 0x2cfdf80, 0x4831bd8)
        github.com/spf13/cobra@v1.1.1/command.go:958 +0x375
github.com/spf13/cobra.(*Command).Execute(...)
        github.com/spf13/cobra@v1.1.1/command.go:895
github.com/spf13/cobra.(*Command).ExecuteContext(...)
        github.com/spf13/cobra@v1.1.1/command.go:888
main.main()
        github.com/docker/compose-cli/cli/main.go:203 +0xa37

Describe the results you expected:

The compose files to deploy successfully.

Additional information you deem important (e.g. issue happens only occasionally):

Output of docker version:

Client: Docker Engine - Community
 Cloud integration: 1.0.7
 Version:           20.10.2
 API version:       1.41
 Go version:        go1.13.15
 Git commit:        2291f61
 Built:             Mon Dec 28 16:12:42 2020
 OS/Arch:           darwin/amd64
 Context:           default
 Experimental:      true

Server: Docker Engine - Community
 Engine:
  Version:          20.10.2
  API version:      1.41 (minimum version 1.12)
  Go version:       go1.13.15
  Git commit:       8891c58
  Built:            Mon Dec 28 16:15:28 2020
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.4.3
  GitCommit:        269548fa27e0089a8b8278fc4fc781d7f65a939b
 runc:
  Version:          1.0.0-rc92
  GitCommit:        ff819c7e9184c13b7c2607fe6c30ae19403a7aff
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

Output of docker context show:
You can also run docker context inspect context-name to give us more details but don't forget to remove sensitive content.

[
    {
        "Name": "azure",
        "Metadata": {
            "Description": "rg-docker@northeurope",
            "Type": "aci"
        },
        "Endpoints": {
            "aci": {
                "Location": "northeurope",
                "ResourceGroup": "rg-docker",
                "SubscriptionID": "REDACTED"
            },
            "docker": {
                "SkipTLSVerify": false
            }
        },
        "TLSMaterial": {},
        "Storage": {
            "MetadataPath": "/Users/chrisb/.docker/contexts/meta/0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef",
            "TLSPath": "/Users/chrisb/.docker/contexts/tls/0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
        }
    }
]

Output of docker info:

Client:
 Context:    default
 Debug Mode: false
 Plugins:
  app: Docker App (Docker Inc., v0.9.1-beta3)
  buildx: Build with BuildKit (Docker Inc., v0.5.1-docker)
  scan: Docker Scan (Docker Inc., v0.5.0)

Server:
 Containers: 22
  Running: 0
  Paused: 0
  Stopped: 22
 Images: 162
 Server Version: 20.10.2
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Native Overlay Diff: true
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 1
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 io.containerd.runtime.v1.linux runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 269548fa27e0089a8b8278fc4fc781d7f65a939b
 runc version: ff819c7e9184c13b7c2607fe6c30ae19403a7aff
 init version: de40ad0
 Security Options:
  seccomp
   Profile: default
 Kernel Version: 4.19.121-linuxkit
 Operating System: Docker Desktop
 OSType: linux
 Architecture: x86_64
 CPUs: 2
 Total Memory: 7.779GiB
 Name: docker-desktop
 ID: KXAW:KOVW:XJST:6JYM:4JEB:3NVO:FNCA:SL2C:C5YW:66QU:CHXM:IJYN
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 HTTP Proxy: gateway.docker.internal:3128
 HTTPS Proxy: gateway.docker.internal:3129
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false

Additional environment details (AWS ECS, Azure ACI, local, etc.):

Docker Desktop 3.1.0 (51484)
Azure ACI

[chris-crone]

Thanks for the report @chrisbecke! We'll take a look