Environment Variable substitution not working

[surajssd]

I am using following docker-compose.yml file

$ cat docker-compose.yml 
version: "2"

services:
  mariadb:
    image: centos/mariadb
    ports:
      - "$DB_PORT"
    environment:
      MYSQL_ROOT_PASSWORD: $ROOT_PASS
      MYSQL_DATABASE: $DB_NAME
      MYSQL_PASSWORD: $DB_PASS
      MYSQL_USER: $DB_USER

  etherpad:
    image: centos/etherpad
    ports:
      - "80:9001"
    depends_on:
      - mariadb
    environment:
      DB_HOST: $DB_HOST
      DB_DBID: $DB_NAME
      DB_PASS: $DB_PASS
      DB_PORT: $DB_PORT
      DB_USER: $DB_USER

and following envs

$ cat envs 
DB_HOST=mariadb
ROOT_PASS=etherpad
DB_NAME=etherpad
DB_PASS=etherpad
DB_USER=etherpad
DB_PORT=3306

error

$ export $(cat envs)
$ ./kompose convert -o output
panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x20 pc=0x64e144]

goroutine 1 [running]:
panic(0x11ef080, 0xc820010140)
    /usr/local/go/src/runtime/panic.go:481 +0x3e6
github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config.Interpolate.func1(0xc8204acc88, 0x7, 0x0, 0x0)
    /home/vagrant/work/src/github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config/interpolation.go:145 +0x84
github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config.parseVariable(0xc8204ac790, 0x8, 0x8, 0xc82015fbe8, 0x0, 0x0, 0x0, 0xc8204ba150)
    /home/vagrant/work/src/github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config/interpolation.go:36 +0x120
github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config.parseInterpolationExpression(0xc8204ac790, 0x8, 0x1, 0xc82015fbe8, 0x0, 0x0, 0xc82015f7a8, 0x4127d8)
    /home/vagrant/work/src/github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config/interpolation.go:74 +0x10f
github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config.parseLine(0xc8204ac790, 0x8, 0xc82015fbe8, 0x0, 0x0, 0x412672)
    /home/vagrant/work/src/github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config/interpolation.go:90 +0xbf
github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config.parseConfig(0xc8204ac718, 0x5, 0xc8204ac6f0, 0x7, 0xc82015f990, 0xc82015fbe8, 0x0, 0x0)
    /home/vagrant/work/src/github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config/interpolation.go:110 +0x532
github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config.parseConfig(0xc8204ac718, 0x5, 0xc8204ac6f0, 0x7, 0xc82015fb68, 0xc82015fbe8, 0x0, 0x0)
    /home/vagrant/work/src/github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config/interpolation.go:117 +0x1d3
github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config.Interpolate(0x0, 0x0, 0xc82015fd38, 0x0, 0x0)
    /home/vagrant/work/src/github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config/interpolation.go:144 +0x1f3
github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config.MergeServicesV2(0xc8204638c0, 0x0, 0x0, 0x0, 0x0, 0xc820463880, 0x12, 0xc82049c000, 0x1d9, 0x3d9, ...)
    /home/vagrant/work/src/github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config/merge_v2.go:22 +0x12a
github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config.Merge(0xc8204638c0, 0x0, 0x0, 0x0, 0x0, 0xc820463880, 0x12, 0xc82049c000, 0x1d9, 0x3d9, ...)
    /home/vagrant/work/src/github.com/skippbox/kompose/vendor/github.com/docker/libcompose/config/merge.go:40 +0x24c
github.com/skippbox/kompose/vendor/github.com/docker/libcompose/project.(*Project).load(0xc8204651e0, 0xc820463880, 0x12, 0xc82049c000, 0x1d9, 0x3d9, 0x0, 0x0)
    /home/vagrant/work/src/github.com/skippbox/kompose/vendor/github.com/docker/libcompose/project/project.go:178 +0xe5
github.com/skippbox/kompose/vendor/github.com/docker/libcompose/project.(*Project).Parse(0xc8204651e0, 0x0, 0x0)
    /home/vagrant/work/src/github.com/skippbox/kompose/vendor/github.com/docker/libcompose/project/project.go:86 +0x335
github.com/skippbox/kompose/cli/app.loadComposeFile(0xc820463880, 0x12, 0xc820347180, 0x0)
    /home/vagrant/work/src/github.com/skippbox/kompose/cli/app/app.go:733 +0x1b6
github.com/skippbox/kompose/cli/app.Convert(0xc820347180)
    /home/vagrant/work/src/github.com/skippbox/kompose/cli/app/app.go:1028 +0x4b9
github.com/skippbox/kompose/cli/command.ConvertCommand.func1(0xc820347180)
    /home/vagrant/work/src/github.com/skippbox/kompose/cli/command/command.go:30 +0x21
github.com/skippbox/kompose/vendor/github.com/urfave/cli.Command.Run(0x13eb378, 0x7, 0x0, 0x0, 0x0, 0x0, 0x0, 0x159d920, 0x30, 0x0, ...)
    /home/vagrant/work/src/github.com/skippbox/kompose/vendor/github.com/urfave/cli/command.go:179 +0x1399
github.com/skippbox/kompose/vendor/github.com/urfave/cli.(*App).Run(0xc82048ab00, 0xc82000a940, 0x4, 0x4, 0x0, 0x0)
    /home/vagrant/work/src/github.com/skippbox/kompose/vendor/github.com/urfave/cli/app.go:196 +0x137c
main.main()
    /home/vagrant/work/src/github.com/skippbox/kompose/cli/main/main.go:46 +0x5fe

version

$ ./kompose -v
kompose version 0.0.1-alpha (HEAD)

[surajssd]

@ngtuna I would like to fix this one :) to get started with the project.

[kadel]

Go ahead @surajssd, you already fixed same or at least similar bug once 😉

[ngtuna]

@surajssd I guess this bug comes from libcompose. See it: https://github.com/skippbox/kompose/blob/master/cli/app/app.go#L733.
I just call to libcompose parsing function.

If that's the main cause, then you can also make a PR to them :-)