App list does not show installed app from another client

[kinghuang]

Description

I installed a Docker App from my MacBook (Computer A). It appears when I list the apps. But, when I list apps from my iMac (Computer B), no apps are listed.

Steps to reproduce the issue:

1. On computer A, install a Docker app. In this case, named "gitlab-runners".
2. On computer A, list the apps.
3. On computer B, list the apps.

Describe the results you received:

Computer B does not show the installed app.

‣ ~ docker app ls --target-context ba-tools
INSTALLATION APPLICATION LAST ACTION RESULT CREATED MODIFIED REFERENCE

Describe the results you expected:

Computer B should show the installed app like Computer A.

‣ ~ docker app ls --target-context ba-tools
INSTALLATION   APPLICATION            LAST ACTION RESULT  CREATED  MODIFIED REFERENCE
gitlab-runners gitlab-runners (0.1.0) install     success 21 hours 21 hours 

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

Listing stacks from both computers shows the app's stack.

‣ ~ docker --context ba-tools stack ls 
NAME                SERVICES            ORCHESTRATOR
gitlab-runners      1                   Swarm

Output of docker version:

‣ ~ docker --context ba-tools version
Client: Docker Engine - Community
 Version:           19.03.1
 API version:       1.40
 Go version:        go1.12.5
 Git commit:        74b1e89
 Built:             Thu Jul 25 21:18:17 2019
 OS/Arch:           darwin/amd64
 Experimental:      true

Server: Docker Engine - Community
 Engine:
  Version:          19.03.1
  API version:      1.40 (minimum version 1.12)
  Go version:       go1.12.5
  Git commit:       74b1e89
  Built:            Thu Jul 25 21:19:36 2019
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.2.6
  GitCommit:        894b81a4b802e4eb2a91d1ce216b8817763c29fb
 runc:
  Version:          1.0.0-rc8
  GitCommit:        425e105d5a03fabd737a126ad93d62a9eeede87f
 docker-init:
  Version:          0.18.0
  GitCommit:        fec3683

Output of docker app version:

‣ ~ docker app version
Version:               v0.8.0
Git commit:            7eea32b7
Built:                 Thu Jul 25 21:26:00 2019
OS/Arch:               darwin/amd64
Experimental:          off
Renderers:             none
Invocation Base Image: docker/cnab-app-base:v0.8.0

Output of docker info:

Client:
 Debug Mode: false
 Plugins:
  app: Docker Application (Docker Inc., v0.8.0)
  buildx: Build with BuildKit (Docker Inc., v0.2.2-10-g3f18b65-tp-docker)

Server:
 Containers: 3
  Running: 2
  Paused: 0
  Stopped: 1
 Images: 1
 Server Version: 19.03.1
 Storage Driver: overlay2
  Backing Filesystem: xfs
  Supports d_type: true
  Native Overlay Diff: true
 Logging Driver: local
 Cgroup Driver: cgroupfs
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: active
  NodeID: vj7l9j66hwohsr571nrjb8e7e
  Is Manager: true
  ClusterID: dghus6qqcd3pbzm639rtm767k
  Managers: 3
  Nodes: 5
  Default Address Pool: 10.0.0.0/8  
  SubnetSize: 24
  Data Path Port: 4789
  Orchestration:
   Task History Retention Limit: 5
  Raft:
   Snapshot Interval: 10000
   Number of Old Snapshots to Retain: 0
   Heartbeat Tick: 1
   Election Tick: 10
  Dispatcher:
   Heartbeat Period: 5 seconds
  CA Configuration:
   Expiry Duration: 3 months
   Force Rotate: 0
  Autolock Managers: false
  Root Rotation In Progress: false
  Node Address: 10.54.21.111
  Manager Addresses:
   10.54.11.180:2377
   10.54.21.111:2377
   10.54.31.42:2377
 Runtimes: runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 894b81a4b802e4eb2a91d1ce216b8817763c29fb
 runc version: 425e105d5a03fabd737a126ad93d62a9eeede87f
 init version: fec3683
 Security Options:
  seccomp
   Profile: default
 Kernel Version: 4.14.123-111.109.amzn2.x86_64
 Operating System: Amazon Linux 2
 OSType: linux
 Architecture: x86_64
 CPUs: 2
 Total Memory: 961.5MiB
 Name: ip-10-54-21-111.transzap.com
 ID: 55HI:DLYV:DLBE:EBXZ:IEUX:ERAY:YZOP:CAPB:57LD:CNT2:JVQL:DKFO
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false

WARNING: bridge-nf-call-ip6tables is disabled

Additional environment details (AWS, VirtualBox, physical, etc.):

[kinghuang]

I've just discovered that installation information seems to be stored locally in the calling client's Docker config directory ($DOCKER_CONFIG/app/installations/). Does this make installations completely non-portable?