Configuration

Environment Variables

Per Process

process2:
  environment:
    - "I_AM_LOCAL_EV=42"

Global

environment:
  - "I_AM_GLOBAL_EV=42"
processes:
  process2:
    command: "chmod 666 /path/to/file"
  environment:
    - "I_AM_LOCAL_EV=42"

Default environment variables:

PC_PROC_NAME - Defines the process name as defined in the process-compose.yaml file.

PC_REPLICA_NUM - Defines the process replica number. Useful for port collision avoidance for processes with multiple replicas.

.env file

VERSION='1.2.3'
DB_USER='USERNAME'
DB_PASSWORD='VERY_STRONG_PASSWORD'
WAIT_SEC=60

Override ${var} and $var from environment variables or .env values

processes:
  downloader:
    command: "python3 data_downloader_${VERSION}.py -s 'data.source.B.uri'"
    availability:
      restart: "always"
      backoff_seconds: ${WAIT_SEC}
    environment:
      - 'OUTPUT_DIR=/path/to/B/data'

Specify which configuration files to use

process-compose -f "path/to/process-compose-file.yaml"

Auto discover configuration files

The following discovery order is used: compose.yml, compose.yaml, process-compose.yml, process-compose.yaml. If multiple files are present the first one will be used.

Merge 2 or more configuration files with override values

process-compose -f "path/to/process-compose-file.yaml" -f "path/to/process-compose-override-file.yaml"

Using multiple process-compose files lets you customize a process-compose application for different environments or different workflows.

See the Merging Configuration for more information on merging files.

Backend

For cases where your process compose requires a non default or transferable backend definition, setting an environment variable won't do. For that, you can configure it directly in the process-compose.yaml file:

version: "0.5"
shell:
  shell_command: "python3"
  shell_argument: "-m"
processes:
  http:
    command: "server.py"

Note: please make sure that the shell.shell_command value is in your $PATH

Linux

The default backend is bash. You can define a different backend with a COMPOSE_SHELL environment variable.

Windows

The default backend is cmd. You can define a different backend with a COMPOSE_SHELL environment variable.

process1:
  command: "python -c print(str(40+2))"
  #note that the same command for bash/zsh would look like: "python -c 'print(str(40+2))'"

Using powershell backend had some funky behavior (like missing command1 && command2 functionality in older versions). If you need to run powershell scripts, use the following syntax:

process2:
  command: "powershell.exe ./test.ps1 arg1 arg2 argN"

macOS

The default backend is bash. You can define a different backend with a COMPOSE_SHELL environment variable.

Namespaces

Assigning namespaces to processes allows better grouping and sorting, especially in TUI:

processes:
  process1:
    command: "tail -f -n100 process-compose-${USER}.log"
    working_dir: "/tmp"
    namespace: debug # if not defined 'default' namespace is automatically assigned to each process

Note: By default process-compose will start process from all the configured namespaces. To start a sub set of the configured namespaces (ns1, ns2, ns3):

process-compose -n ns1 -n ns3
# will start only ns1 and ns3. ns2 namespace won't run and won't be visible in the TUI

Misc

Strict Configuration Validation

To avoid minor proces-compose.yaml configuration errors and typos it is recommended to enable is_strict flag:

version: "0.5"
is_strict: true
processes:
  process1:
   commnad: "sleep 1" # <-- notice the typo here

The above configuration will fail the Process Compose start and exit with error code 1:

unknown key commnad found in process process1