Merge #153

153: Add service.healthcheck and extend service.depends_on r=roberth a=t4ccer

Add option to define custom health checks for services, and extend `depends_on` so it can also include `<service>.condition` field for conditions based on health checks.

Co-authored-by: t4ccer <t4ccer@gmail.com>

CHANGELOG.md

@@ -1,5 +1,15 @@
 # Revision history for Arion
 
+## Next
+
+### Changed
+
+* Healthcheck-based dependencies in `service.depends_on`.
+
+### Added
+
+* Support `service.healthcheck` for defining custom healthchecks.
+
 ## 0.1.3.0 -- 2020-05-03
 
 ### Changed

docs/modules/ROOT/partials/NixOSOptions.adoc

@@ -514,7 +514,7 @@ See link:https://docs.docker.com/compose/compose-file/#depends_on[Docker Compose
 [discrete]
 === details
 
-Type:: list of strings
+Type:: list of strings or attribute set of submodules
 Default::
 +
 ----
@@ -668,6 +668,123 @@ Default::
 
 No Example:: {blank}
 
+== services.<name>.service.healthcheck
+
+None
+
+[discrete]
+=== details
+
+Type:: submodule
+No Default:: {blank}
+
+No Example:: {blank}
+
+== services.<name>.service.healthcheck.interval
+
+See link:https://docs.docker.com/compose/compose-file/#healthcheck[Docker Compose#healthcheck]
+
+[discrete]
+=== details
+
+Type:: string
+Default::
++
+----
+"30s"
+----
+
+
+Example::
++
+----
+"1m"
+----
+
+
+== services.<name>.service.healthcheck.retries
+
+See link:https://docs.docker.com/compose/compose-file/#healthcheck[Docker Compose#healthcheck]
+
+[discrete]
+=== details
+
+Type:: signed integer
+Default::
++
+----
+3
+----
+
+
+No Example:: {blank}
+
+== services.<name>.service.healthcheck.start_period
+
+See link:https://docs.docker.com/compose/compose-file/#healthcheck[Docker Compose#healthcheck]
+
+[discrete]
+=== details
+
+Type:: string
+Default::
++
+----
+"0s"
+----
+
+
+Example::
++
+----
+"30s"
+----
+
+
+== services.<name>.service.healthcheck.test
+
+See link:https://docs.docker.com/compose/compose-file/#healthcheck[Docker Compose#healthcheck]
+
+[discrete]
+=== details
+
+Type:: null or list of strings
+Default::
++
+----
+null
+----
+
+
+Example::
++
+----
+["CMD","pg_isready"]
+----
+
+
+== services.<name>.service.healthcheck.timeout
+
+See link:https://docs.docker.com/compose/compose-file/#healthcheck[Docker Compose#healthcheck]
+
+[discrete]
+=== details
+
+Type:: string
+Default::
++
+----
+"30s"
+----
+
+
+Example::
++
+----
+"10s"
+----
+
+
 == services.<name>.service.hostStoreAsReadOnly
 
 Adds a ':ro' (read-only) access mode to the host nix store bind mount.

src/nix/modules/service/docker-compose-service.nix

@@ -4,11 +4,11 @@
    the user-facing options service.image, service.volumes, etc.
 
  */
-{ pkgs, lib, config, ... }:
+{ pkgs, lib, config, options, ... }:
 
 let
   inherit (lib) mkOption types;
-  inherit (types) listOf nullOr attrsOf str either int bool;
+  inherit (types) listOf nullOr attrsOf str either int bool submodule enum;
 
   link = url: text:
     ''link:${url}[${text}]'';
@@ -100,11 +100,62 @@ in
       default = null;
       description = dockerComposeRef "container_name";
     };
-    service.depends_on = mkOption {
-      type = listOf str;
+    service.depends_on =
+      let conditionsModule = {
+            options = {
+              condition = mkOption {
+                type = enum ["service_started" "service_healthy" "service_completed_successfully"];
+                description = dockerComposeRef "depends_on";
+                default = "service_started";
+              };
+            };
+          };
+       in mkOption {
+         type = either (listOf str) (attrsOf (submodule conditionsModule));
          default = [];
          description = dockerComposeRef "depends_on";
        };
+    service.healthcheck = mkOption {
+      type = submodule ({ config, options, ...}: {
+        options = {
+          _out = mkOption {
+            internal = true;
+            default = lib.optionalAttrs (options.test.highestPrio < 1500) {
+              inherit (config) test interval timeout start_period retries;
+            };
+          };
+          test = mkOption {
+            type = nullOr (listOf str);
+            default = null;
+            example = [ "CMD" "pg_isready" ];
+            description = dockerComposeRef "healthcheck";
+          };
+          interval = mkOption {
+            type = str;
+            default = "30s";
+            example = "1m";
+            description = dockerComposeRef "healthcheck";
+          };
+          timeout = mkOption {
+            type = str;
+            default = "30s";
+            example = "10s";
+            description = dockerComposeRef "healthcheck";
+          };
+          start_period = mkOption {
+            type = str;
+            default = "0s";
+            example = "30s";
+            description = dockerComposeRef "healthcheck";
+          };
+          retries = mkOption {
+            type = int;
+            default = 3;
+            description = dockerComposeRef "healthcheck";
+          };
+        };
+      });
+    };
     service.devices = mkOption {
       type = listOf str;
       default = [];
@@ -250,6 +301,8 @@ in
     inherit (config.service) container_name;
   } // lib.optionalAttrs (config.service.depends_on != []) {
     inherit (config.service) depends_on;
+  } // lib.optionalAttrs (options.service.healthcheck.highestPrio < 1500) {
+    healthcheck = config.service.healthcheck._out;
   } // lib.optionalAttrs (config.service.devices != []) {
     inherit (config.service) devices;
   } // lib.optionalAttrs (config.service.entrypoint != null) {