Merge pull request #4 from buildkite-plugins/codex/hosted-agent-cache

feat: add hosted agent cache support

Author: lox

README.md

@@ -31,10 +31,25 @@ steps:
     command: go test ./...
 ```
 
+## Hosted Agent Cache Volumes
+
+```yml
+cache: ".buildkite/cache-volume"
+
+steps:
+  - label: ":wrench: Test"
+    plugins:
+      - buildkite-plugins/mise#v1.0.0: ~
+    command: go test ./...
+```
+
+When running on Buildkite hosted agents, the plugin automatically uses `/cache/bkcache/mise` as `MISE_DATA_DIR` if a cache volume is attached. Buildkite only mounts that volume when the pipeline or step defines `cache`, so you still need to request one in `pipeline.yml`.
+
 ## Configuration
 
 - `version` (default: `latest`): mise version to install.
 - `dir` (default: checkout directory): directory where `mise install` and `mise env` run.
+- `cache-dir` (default: unset): directory to use for `MISE_DATA_DIR`. This is mainly useful on self-hosted agents with a persistent disk.
 
 ## Repo Requirements
 
@@ -44,7 +59,7 @@ The target directory must contain one of:
 - `.mise.toml`
 - `.tool-versions`
 
-Advanced `mise` behavior should be configured with normal step environment variables such as `MISE_DATA_DIR`, `MISE_LOG_LEVEL`, or `MISE_EXPERIMENTAL`, not plugin-specific config keys.
+`MISE_DATA_DIR` still takes precedence over plugin configuration. Advanced `mise` behavior should otherwise be configured with normal step environment variables such as `MISE_LOG_LEVEL` or `MISE_EXPERIMENTAL`.
 
 ## Development
 

hooks/pre-command

@@ -47,6 +47,44 @@ cleanup_install_mise() {
   rm -rf "$2"
 }
 
+hosted_cache_volume_root() {
+  printf '%s' "${MISE_HOSTED_CACHE_VOLUME_ROOT:-/cache/bkcache}"
+}
+
+resolve_mise_dir() {
+  local cache_dir_cfg
+  local hosted_cache_root
+
+  if [ -n "${MISE_DATA_DIR:-}" ]; then
+    MISE_DIR_SOURCE="MISE_DATA_DIR environment variable"
+    MISE_DIR="$MISE_DATA_DIR"
+    return
+  fi
+
+  cache_dir_cfg="$(plugin_cfg cache-dir)"
+  if [ -n "$cache_dir_cfg" ]; then
+    MISE_DIR_SOURCE="plugin cache-dir configuration"
+    MISE_DIR="$cache_dir_cfg"
+    return
+  fi
+
+  hosted_cache_root="$(hosted_cache_volume_root)"
+  if [ "${BUILDKITE_COMPUTE_TYPE:-self-hosted}" = "hosted" ] && [ -d "$hosted_cache_root" ] && [ -w "$hosted_cache_root" ]; then
+    MISE_DIR_SOURCE="Buildkite hosted agent cache volume"
+    MISE_DIR="${hosted_cache_root}/mise"
+    return
+  fi
+
+  if [ -n "${XDG_DATA_HOME:-}" ]; then
+    MISE_DIR_SOURCE="XDG_DATA_HOME fallback"
+    MISE_DIR="${XDG_DATA_HOME}/mise"
+    return
+  fi
+
+  MISE_DIR_SOURCE="HOME fallback"
+  MISE_DIR="${HOME}/.local/share/mise"
+}
+
 detect_platform() {
   local os
   local arch
@@ -173,55 +211,58 @@ ensure_mise_config_present() {
   exit 1
 }
 
-required_version_raw="$(plugin_cfg_default version latest)"
-dir_cfg="$(plugin_cfg dir)"
+main() {
+  local current_version
+  local dir_cfg
+  local required_version_raw
 
-if [ -n "$dir_cfg" ]; then
-  WORKING_DIRECTORY="$dir_cfg"
-else
-  WORKING_DIRECTORY="${BUILDKITE_BUILD_CHECKOUT_PATH:-${PWD}}"
-fi
+  required_version_raw="$(plugin_cfg_default version latest)"
+  dir_cfg="$(plugin_cfg dir)"
 
-if [ -n "${MISE_DATA_DIR:-}" ]; then
-  MISE_DIR="$MISE_DATA_DIR"
-elif [ -n "${XDG_DATA_HOME:-}" ]; then
-  MISE_DIR="${XDG_DATA_HOME}/mise"
-else
-  MISE_DIR="${HOME}/.local/share/mise"
-fi
+  if [ -n "$dir_cfg" ]; then
+    WORKING_DIRECTORY="$dir_cfg"
+  else
+    WORKING_DIRECTORY="${BUILDKITE_BUILD_CHECKOUT_PATH:-${PWD}}"
+  fi
 
-MISE_BIN="${MISE_DIR}/bin"
-MISE_BINARY="${MISE_BIN}/mise"
+  resolve_mise_dir
+  MISE_BIN="${MISE_DIR}/bin"
+  MISE_BINARY="${MISE_BIN}/mise"
 
-if [ "$required_version_raw" = latest ]; then
-  VERSION="$(latest_version)"
-else
-  VERSION="${required_version_raw#v}"
-fi
-VERSION="${VERSION#v}"
+  echo "Using mise data dir: ${MISE_DIR} (${MISE_DIR_SOURCE})"
 
-PLATFORM="$(detect_platform)"
-require_cmd curl
-require_cmd tar
+  if [ "$required_version_raw" = latest ]; then
+    VERSION="$(latest_version)"
+  else
+    VERSION="${required_version_raw#v}"
+  fi
+  VERSION="${VERSION#v}"
 
-current_version="$(installed_version)"
-if [ -z "$current_version" ] || [ "$current_version" != "$VERSION" ]; then
-  install_mise "$VERSION" "$PLATFORM"
-fi
+  PLATFORM="$(detect_platform)"
+  require_cmd curl
+  require_cmd tar
 
-ensure_mise_config_present
+  current_version="$(installed_version)"
+  if [ -z "$current_version" ] || [ "$current_version" != "$VERSION" ]; then
+    install_mise "$VERSION" "$PLATFORM"
+  fi
 
-run_mise --version
-run_mise install
+  ensure_mise_config_present
 
-if [ -z "${BUILDKITE_ENV_FILE:-}" ]; then
-  echo "BUILDKITE_ENV_FILE is not set" >&2
-  exit 1
-fi
+  run_mise --version
+  run_mise install
 
-append_export MISE_DATA_DIR "$MISE_DIR"
-append_export MISE_TRUSTED_CONFIG_PATHS "$WORKING_DIRECTORY"
-append_export MISE_YES "1"
-run_mise env --shell bash >> "$BUILDKITE_ENV_FILE"
+  if [ -z "${BUILDKITE_ENV_FILE:-}" ]; then
+    echo "BUILDKITE_ENV_FILE is not set" >&2
+    exit 1
+  fi
+
+  append_export MISE_DATA_DIR "$MISE_DIR"
+  append_export MISE_TRUSTED_CONFIG_PATHS "$WORKING_DIRECTORY"
+  append_export MISE_YES "1"
+  run_mise env --shell bash >> "$BUILDKITE_ENV_FILE"
+
+  echo "~~~ :white_check_mark: mise setup complete"
+}
 
-echo "~~~ :white_check_mark: mise setup complete"
+main "$@"

plugin.yml

@@ -14,3 +14,6 @@ configuration:
     dir:
       type: string
       description: Directory where `mise install` and `mise env` run. Defaults to the checkout directory.
+    cache-dir:
+      type: string
+      description: Directory to use for `MISE_DATA_DIR`. Useful for persistent caches on self-hosted agents.

tests/pre-command.bats

@@ -9,9 +9,24 @@ setup() {
   export MISE_DATA_DIR="${TEST_TMPDIR}/mise-data"
   export BUILDKITE_PLUGIN_MISE_VERSION="1.0.0"
 
-  mkdir -p "${BUILDKITE_BUILD_CHECKOUT_PATH}" "${MISE_DATA_DIR}/bin" "${MISE_DATA_DIR}/shims"
+  mkdir -p "${BUILDKITE_BUILD_CHECKOUT_PATH}"
+  write_mise_mock "${MISE_DATA_DIR}"
 
-  cat > "${MISE_DATA_DIR}/bin/mise" <<'MOCK'
+  export MISE_MOCK_LOG="${TEST_TMPDIR}/mise.log"
+  : > "${MISE_MOCK_LOG}"
+
+  unset BUILDKITE_PLUGIN_MISE_CACHE_DIR
+  unset BUILDKITE_PLUGIN_MISE_DIR
+  unset BUILDKITE_COMPUTE_TYPE
+  unset MISE_HOSTED_CACHE_VOLUME_ROOT
+}
+
+write_mise_mock() {
+  local data_dir="$1"
+
+  mkdir -p "${data_dir}/bin" "${data_dir}/shims"
+
+  cat > "${data_dir}/bin/mise" <<'MOCK'
 #!/usr/bin/env bash
 set -euo pipefail
 
@@ -40,12 +55,7 @@ case "${cmd}" in
     ;;
 esac
 MOCK
-  chmod +x "${MISE_DATA_DIR}/bin/mise"
-
-  export MISE_MOCK_LOG="${TEST_TMPDIR}/mise.log"
-  : > "${MISE_MOCK_LOG}"
-
-  unset BUILDKITE_PLUGIN_MISE_DIR
+  chmod +x "${data_dir}/bin/mise"
 }
 
 teardown() {
@@ -134,6 +144,35 @@ MOCK
   grep -F "env pwd=${subdir} env --shell bash" "${MISE_MOCK_LOG}"
 }
 
+@test "uses cache-dir config when MISE_DATA_DIR is unset" {
+  cache_dir="${TEST_TMPDIR}/self-hosted-cache"
+  unset MISE_DATA_DIR
+  export BUILDKITE_PLUGIN_MISE_CACHE_DIR="${cache_dir}"
+  write_mise_mock "${cache_dir}"
+  printf 'go 1.0.0\n' > "${BUILDKITE_BUILD_CHECKOUT_PATH}/.tool-versions"
+
+  run bash hooks/pre-command
+
+  [ "${status}" -eq 0 ]
+  grep -F "Using mise data dir: ${cache_dir} (plugin cache-dir configuration)" <<< "${output}"
+  grep -F "export MISE_DATA_DIR=${cache_dir}" "${BUILDKITE_ENV_FILE}"
+}
+
+@test "uses hosted cache volume automatically when available" {
+  hosted_cache_root="${TEST_TMPDIR}/hosted-cache"
+  unset MISE_DATA_DIR
+  export BUILDKITE_COMPUTE_TYPE="hosted"
+  export MISE_HOSTED_CACHE_VOLUME_ROOT="${hosted_cache_root}"
+  write_mise_mock "${hosted_cache_root}/mise"
+  printf 'go 1.0.0\n' > "${BUILDKITE_BUILD_CHECKOUT_PATH}/.tool-versions"
+
+  run bash hooks/pre-command
+
+  [ "${status}" -eq 0 ]
+  grep -F "Using mise data dir: ${hosted_cache_root}/mise (Buildkite hosted agent cache volume)" <<< "${output}"
+  grep -F "export MISE_DATA_DIR=${hosted_cache_root}/mise" "${BUILDKITE_ENV_FILE}"
+}
+
 @test "fails when no mise config exists" {
   run bash hooks/pre-command