main
1#!/usr/bin/env nix-shell
2#! nix-shell -i bash -p jq
3# shellcheck shell=bash
4
5# DetectRuntime.sh - Detect Docker or Podman runtime and return information
6# Usage: DetectRuntime.sh [--runtime docker|podman] [--json]
7
8set -euo pipefail
9
10show_usage() {
11 cat <<EOF
12Usage: DetectRuntime.sh [OPTIONS]
13
14Detect container runtime (Docker or Podman) and return information.
15
16OPTIONS:
17 --runtime RUNTIME Force specific runtime (docker|podman)
18 --json Output in JSON format
19 -h, --help Show this help message
20
21EXAMPLES:
22 DetectRuntime.sh # Auto-detect available runtime
23 DetectRuntime.sh --runtime docker # Force Docker runtime
24 DetectRuntime.sh --json # Output as JSON
25EOF
26}
27
28detect_runtime() {
29 local force_runtime=""
30 local output_json=false
31
32 # Parse arguments
33 while [[ $# -gt 0 ]]; do
34 case $1 in
35 --runtime)
36 force_runtime="$2"
37 shift 2
38 ;;
39 --json)
40 output_json=true
41 shift
42 ;;
43 -h|--help)
44 show_usage
45 exit 0
46 ;;
47 *)
48 echo "ERROR: Unknown option: $1" >&2
49 show_usage >&2
50 exit 1
51 ;;
52 esac
53 done
54
55 local runtime=""
56 local compose=""
57 local version=""
58 local rootless="false"
59 local socket=""
60
61 # If specific runtime requested, check only that one
62 if [[ -n "$force_runtime" ]]; then
63 case "$force_runtime" in
64 podman)
65 if ! command -v podman &>/dev/null; then
66 echo "ERROR: Podman requested but not found in PATH" >&2
67 exit 1
68 fi
69 runtime="podman"
70 ;;
71 docker)
72 if ! command -v docker &>/dev/null; then
73 echo "ERROR: Docker requested but not found in PATH" >&2
74 exit 1
75 fi
76 runtime="docker"
77 ;;
78 *)
79 echo "ERROR: Invalid runtime '$force_runtime'. Must be 'docker' or 'podman'" >&2
80 exit 1
81 ;;
82 esac
83 fi
84
85 # Auto-detect if no runtime forced
86 if [[ -z "$runtime" ]]; then
87 # Check for Podman first (preference for rootless)
88 if command -v podman &>/dev/null; then
89 runtime="podman"
90 # Fall back to Docker
91 elif command -v docker &>/dev/null; then
92 runtime="docker"
93 else
94 echo "ERROR: Neither Docker nor Podman found in PATH" >&2
95 exit 1
96 fi
97 fi
98
99 # Get runtime-specific information
100 case "$runtime" in
101 podman)
102 version=$(podman --version | awk '{print $3}')
103
104 # Check if running rootless
105 if podman info --format '{{.Host.Security.Rootless}}' 2>/dev/null | grep -q "true"; then
106 rootless="true"
107 socket="unix://$XDG_RUNTIME_DIR/podman/podman.sock"
108 else
109 rootless="false"
110 socket="unix:///run/podman/podman.sock"
111 fi
112
113 # Check for podman-compose
114 if command -v podman-compose &>/dev/null; then
115 compose="podman-compose"
116 elif command -v docker-compose &>/dev/null; then
117 compose="docker-compose"
118 else
119 compose="none"
120 fi
121 ;;
122 docker)
123 version=$(docker --version | awk '{print $3}' | tr -d ',')
124 rootless="false"
125 socket="unix:///var/run/docker.sock"
126
127 # Check for docker-compose
128 if docker compose version &>/dev/null 2>&1; then
129 compose="docker-compose-plugin"
130 elif command -v docker-compose &>/dev/null; then
131 compose="docker-compose"
132 else
133 compose="none"
134 fi
135 ;;
136 esac
137
138 # Output format
139 if [[ "$output_json" == true ]]; then
140 jq -n \
141 --arg runtime "$runtime" \
142 --arg version "$version" \
143 --arg compose "$compose" \
144 --arg rootless "$rootless" \
145 --arg socket "$socket" \
146 '{
147 runtime: $runtime,
148 version: $version,
149 compose: $compose,
150 rootless: ($rootless == "true"),
151 socket: $socket
152 }'
153 else
154 echo "Runtime: $runtime"
155 echo "Version: $version"
156 echo "Compose: $compose"
157 echo "Rootless: $rootless"
158 echo "Socket: $socket"
159 fi
160}
161
162detect_runtime "$@"