Merge pull request #4 from improbable-eng/fix-multiples

.buildkite/local-pipeline.yml

@@ -6,7 +6,5 @@ steps:
           pre-command: |
             echo "pre-command hook"
             echo "with two commands"
-          command.bat: echo "command hook .bat"
           post-command: echo "post-command hook"
-          pre-artifact.cmd: echo "pre-artifact hook .cmd"
-          pre-exit: echo  "pre-exit hook"
+          pre-exit: echo "pre-exit hook"

changelog.md

@@ -0,0 +1,55 @@
+# Changelog
+
+## 0.4.0
+
+### Fixed
+
+- Allow multiple steps to use metahooks for the same hook but with different content.
+- Inject `bash` shebang and Bash Strict Mode (`set -euo pipefail`) so that if metahooks fail with errors the job halts rather than continuing.
+
+  Bash Strict Mode is provided by
+  - `set -o errexit` - halt on error
+  - `set -o nounset` - halt if variable is unset
+  - `set -o pipefail` - halt if a command inside a pipe fails
+
+  You can override those choices by setting different values (e.g. `set +o nounset`) within your metahook.
+
+### Removed
+
+- **Breaking change** Removed support for `command` metahook.
+
+    Buildkite special-cases this which triggers edge-cases that a `command` metahook would need to work around.
+
+    If you want to override behaviour here, you will need to modify the automation you're running rather than inject a difference via metahook.
+
+- **Breaking change** Removed Windows Batch (`.bat`, `.cmd`) support.
+
+    Sorry if this impacts you.
+
+    To transition from a Windows Batch metahook like
+
+    ```yaml
+    - label: my-step
+      command: echo "hello world"
+      plugins:
+        - improbable-eng/metahook#0.3.0:
+            post-checkout.bat: scripts/windows-setup.bat
+            post-artifact.bat: |
+              call some-batch-file.bat
+              echo "Step finished!"
+    ```
+
+    to
+
+    ```yaml
+    - label: my-step
+      command: echo "hello world"
+      plugins:
+        - improbable-eng/metahook#0.4.0:
+            post-checkout: scripts/windows-setup.sh
+            post-artifact: |
+              some-bash-script-that-was-the-batch-file.sh
+              echo "Step finished!"
+    ```
+
+    To transition Windows Batch shell scripts to bash shell scripts [here is a porting guide](https://www.tldp.org/LDP/abs/html/dosbatch.html).

contributing.md

@@ -4,17 +4,22 @@
 make vendorize local_run
 ```
 
-On macOS & linux, the output should contain
+## Expected output
+
+### On macOS & linux, the output should contain
 
 ```txt
+~~~ Running plugin metahook environment hook
+$ .buildkite/plugins/metahook/hooks/environment
+# BUILDKITE_METAHOOK_HOOKS_PATH changed
+
 ~~~ Running plugin metahook pre-command hook
 $ .buildkite/plugins/metahook/hooks/pre-command
 pre-command hook
 with two commands
 
-~~~ Running commands
-$ trap 'kill -- $$' INT TERM QUIT; echo "Hello World"
-Hello World
+~~~ Running plugin metahook command hook
+$ .buildkite/plugins/metahook/hooks/command
 
 ~~~ Running plugin metahook post-command hook
 $ .buildkite/plugins/metahook/hooks/post-command
@@ -24,3 +29,40 @@ post-command hook
 $ .buildkite/plugins/metahook/hooks/pre-exit
 pre-exit hook
 ```
+
+### On Windows, the output should contain
+
+```txt
+>>> Executing command step Test
+
+~~~ Preparing plugins
+> cd C:\Users\Pete\src\improbable\metahook-buildkite-plugin
+
+~~~ Running plugin metahook environment hook
+> .buildkite\plugins\metahook\hooks\environment
+> cd C:\Users\Pete\src\improbable\metahook-buildkite-plugin\c\Users\Pete\src\improbable\metahook-buildkite-plugin
+# BUILDKITE_METAHOOK_HOOKS_PATH changed
+
+~~~ Running plugin metahook pre-command hook
+> .buildkite\plugins\metahook\hooks\pre-command
+pre-command hook
+with two commands
+> cd C:\Users\Pete\src\improbable\metahook-buildkite-plugin\c\Users\Pete\src\improbable\metahook-buildkite-plugin
+
+~~~ Running plugin metahook command hook
+> .buildkite\plugins\metahook\hooks\command
+> cd C:\Users\Pete\src\improbable\metahook-buildkite-plugin\c\Users\Pete\src\improbable\metahook-buildkite-plugin
+
+~~~ Running plugin metahook post-command hook
+> .buildkite\plugins\metahook\hooks\post-command
+post-command hook
+> cd C:\Users\Pete\src\improbable\metahook-buildkite-plugin\c\Users\Pete\src\improbable\metahook-buildkite-plugin
+
+~~~ Running plugin metahook pre-exit hook
+> .buildkite\plugins\metahook\hooks\pre-exit
+pre-exit hook
+> cd C:\Users\Pete\src\improbable\metahook-buildkite-plugin\c\Users\Pete\src\improbable\metahook-buildkite-plugin
+
+>>> Command succeeded in 3.2662428s
+>>> Build finished in 3.2672403s
+```

hooks/checkout

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+set -euo pipefail
+"${BASH_SOURCE%/*}/run-hook.sh" "$(basename "${BASH_SOURCE[0]}")"

hooks/environment

@@ -1,46 +1,15 @@
 #!/usr/bin/env bash
+set -euo pipefail
 
-# The list of possible hooks to implement.
-declare -a hooks=(
-    # "environment" # not allowed
-    "pre-checkout"
-    "checkout"
-    "post-checkout"
-    "pre-command"
-    "command"
-    "post-command"
-    "pre-artifact"
-    "post-artifact"
-    "pre-exit"
-)
+BUILDKITE_METAHOOK_HOOKS_PATH="$(mktemp -d)"
+export BUILDKITE_METAHOOK_HOOKS_PATH
+env | sort | grep "BUILDKITE_PLUGIN_METAHOOK" | uniq >"${BUILDKITE_METAHOOK_HOOKS_PATH}/vars"
 
-# The list of possible file extensions for hooks.
-declare -a extensions=(
-    ""
-    ".bat"
-    ".cmd"
-)
+if grep -E 'BUILDKITE_PLUGIN_METAHOOK_.+(\.BAT|\.CMD)=' "${BUILDKITE_METAHOOK_HOOKS_PATH}/vars"; then
+  echo "Sorry, we had to remove Windows Batch file support in 0.4.0."
+  echo "Please refer to https://github.com/improbable-eng/metahook-buildkite-plugin/tree/master/changelog.md#0.4.0"
+  echo ""
+  exit 1
+fi
 
-hooks_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-
-vars="$(mktemp)"
-cleanup() {
-  rm -rf "${vars}"
-}
-trap cleanup EXIT
-
-env | sort | grep "METAHOOK" | uniq >"${vars}"
-
-for hook_name in "${hooks[@]}"; do
-  for ext in "${extensions[@]}"; do
-    hook_file="${hooks_dir}/${hook_name}${ext}"
-    rm -f "${hook_file}"
-    upperd="$(echo "${hook_name}${ext}" | tr "[:lower:]" "[:upper:]")"
-    var_name="BUILDKITE_PLUGIN_METAHOOK_${upperd//-/_}"
-    if grep "${var_name}" <"${vars}"; then
-      # Note: ! syntax here is dynamic variable expansion. That is
-      # use the var_name string's variable value.
-      echo "${!var_name}" >"${hook_file}"
-    fi
-  done
-done
+"${BASH_SOURCE%/*}/run-hook.sh" "$(basename "${BASH_SOURCE[0]}")"

hooks/post-artifact

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+set -euo pipefail
+"${BASH_SOURCE%/*}/run-hook.sh" "$(basename "${BASH_SOURCE[0]}")"

hooks/post-checkout

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+set -euo pipefail
+"${BASH_SOURCE%/*}/run-hook.sh" "$(basename "${BASH_SOURCE[0]}")"

hooks/post-command

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+set -euo pipefail
+"${BASH_SOURCE%/*}/run-hook.sh" "$(basename "${BASH_SOURCE[0]}")"

hooks/pre-artifact

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+set -euo pipefail
+"${BASH_SOURCE%/*}/run-hook.sh" "$(basename "${BASH_SOURCE[0]}")"

hooks/pre-command

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+set -euo pipefail
+"${BASH_SOURCE%/*}/run-hook.sh" "$(basename "${BASH_SOURCE[0]}")"

hooks/pre-exit

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+cleanup() {
+  rm -rf "${BUILDKITE_METAHOOK_HOOKS_PATH}"
+}
+trap cleanup EXIT
+
+"${BASH_SOURCE%/*}/run-hook.sh" "$(basename "${BASH_SOURCE[0]}")"

hooks/run-hook.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+set -euo pipefail
+hook_name="${1:?1st arg needs to be hook name}"
+
+upperd="$(echo "${hook_name}" | tr "[:lower:]" "[:upper:]" | sed "s:-:_:")"
+var_name="BUILDKITE_PLUGIN_METAHOOK_${upperd}"
+
+if grep -q "${var_name}" <"${BUILDKITE_METAHOOK_HOOKS_PATH}/vars"; then
+  hook_file="${BUILDKITE_METAHOOK_HOOKS_PATH}/${hook_name}"
+
+  echo "#\!/usr/bin/env bash" >"${hook_file}"
+  echo "set -o errexit" >>"${hook_file}"
+  echo "set -o nounset" >>"${hook_file}"
+  echo "set -o pipefail" >>"${hook_file}"
+  # Exclamation syntax here is dynamic variable expansion.
+  # That is, use the var_name string to look up the value.
+  echo "${!var_name}" >>"${hook_file}"
+  chmod +x "${hook_file}"
+  exec "${hook_file}"
+fi

readme.md

@@ -9,7 +9,6 @@ common: &common
   plugins:
   - improbable-eng/metahook:
       post-checkout: scripts/setup.sh
-      post-checkout.bat: scripts/windows-setup.bat
       pre-exit: |
         scripts/cleanup.sh
         echo "Step finished!"
@@ -25,6 +24,18 @@ steps:
     <<: *common
 ```
 
+Metahooks execute via a `bash` script, searching your `PATH` for `bash`.
+
+Metahooks execute in Bash Strict Mode.
+
+Bash Strict Mode is provided by
+
+- `set -o errexit` - halt on error
+- `set -o nounset` - halt if variable is unset
+- `set -o pipefail` - halt if a command inside a pipe fails
+
+You can override those choices by setting different values (e.g. `set +o nounset`) within your metahook.
+
 ## Contributing
 
 See [contributing](contributing.md)