Added :fn log strategy (#41)

CHANGELOG.md

@@ -1,6 +1,13 @@
 # Change Log
 All notable changes to this project will be documented in this file. This change log follows the conventions of [keepachangelog.com](http://keepachangelog.com/).
 
+## [0.6.0] - 2022-03-26
+### Changed
+- [#55](https://github.com/javahippie/clj-test-containers/issues/55): Upgrade to latest Testcontainers version
+
+### Added
+- [#42](https://github.com/javahippie/clj-test-containers/issues/42): Extend wait strategies
+
 ## [0.5.0] - 2021-08-18
 ### Changed
 - [#49](https://github.com/javahippie/clj-test-containers/issues/49): Updated to latest Testcontainers version

README.md

@@ -69,15 +69,15 @@ Creates a testcontainers instance from a given Docker label and returns them
 #### Config parameters:
 
 | Key                | Type                        | Description                                                                                         |
-| -------------      | :-------------              | :-----                                                                         |
+| -------------      | :-------------              |:----------------------------------------------------------------------------------------------------|
 | `:image-name`      | String, mandatory           | The name and label of an image, e.g. `postgres:12.2`                                                |
 | `:exposed-ports`   | Vector with ints, mandatory | All ports which should be exposed and mapped to a local port                                        |
 | `:env-vars`        | Map                         | A map with environment variables                                                                    |
 | `:command`         | Vector with strings         | The start command of the container                                                                  |
 | `:network`         | Map                         | A map containing the configuration of a Docker Network (see: `create-network`)                      |
 | `:network-aliases` | Map                         | A list of alias names for the container on the network                                              |
-| `:wait-for`        | Map                         | A map containing the wait strategy to use and the condition to check for       |
+| `:wait-for`        | Map                         | A map containing the [wait strategy](docs/wait-strategies.md) to use and the condition to check for |
-| `:log-to`          | Map                         | A map containing the log strategy to use, e.g. {:log-strategy string}          |
+| `:log-to`          | Map                         | A map containing the [log strategy](docs/log-strategies.md) to use, e.g. {:log-strategy string}     |
 
 #### Result:
 
@@ -124,21 +124,21 @@ Initializes a given Testcontainer, which was e.g. provided by a library
 #### Config parameters:
 
 | Key                | Type                                                        | Description                                                                                         |
-| -------------      | :-------------                                              | :-----                                                                         |
+| -------------      | :-------------                                              |:----------------------------------------------------------------------------------------------------|
 | `:container`       | `org.testcontainers.containers.GenericContainer`, mandatory | The name and label of an image, e.g. `postgres:12.2`                                                |
 | `:exposed-ports`   | Vector with ints, mandatory                                 | All ports which should be exposed and mapped to a local port                                        |
 | `:env-vars`        | Map                                                         | A map with environment variables                                                                    |
 | `:command`         | Vector with strings                                         | The start command of the container                                                                  |
 | `:network`         | Map                                                         | A map containing the configuration of a Docker Network (see: `create-network`)                      |
 | `:network-aliases` | Map                                                         | A list of alias names for the container on the network                                              |
-| `:wait-for`        | Map                                                         | A map containing the wait strategy to use and the condition to check for       |
+| `:wait-for`        | Map                                                         | A map containing the [wait strategy](docs/wait-strategies.md) to use and the condition to check for |
-| `:log-to`          | Map                                                         | A map containing the log strategy to use, e.g. {:log-strategy string}          |
+| `:log-to`          | Map                                                         | A map containing the [log strategy](docs/log-strategies.md) to use, e.g. {:log-strategy string}                               |
 |                    |                                                             |                                                                                                     |
 
 #### Result:
 
 | Key              | Type                                      | Description                                                                               |
-| -------------    | :-------------                            | :-----                                                                                    |
+| -------------    | :-------------                            |:------------------------------------------------------------------------------------------|
 | `:container`     | `org.testcontainers.containers.Container` | The Testcontainers instance, accessible for everything this library doesn't provide (yet) |
 | `:exposed-ports` | Vector with ints                          | Value of the same input parameter                                                         |
 | `:env-vars`      | Map                                       | Value of the same input parameter                                                         |
@@ -185,8 +185,8 @@ Creates a testcontainer from a Dockerfile
 | `:command`         | Vector with strings         | The start command of the container                                             |
 | `:network`         | Map                         | A map containing the configuration of a Docker Network (see: `create-network`) |
 | `:network-aliases` | Map                         | A list of alias names for the container on the network                         |
-| `:wait-for`        | Map                         | A map containing the wait strategy to use and the condition to check for       |
+| `:wait-for`        | Map                         | A map containing the [wait strategy](docs/wait-strategies.md) to use and the condition to check for       |
-| `:log-to`          | Map                         | A map containing the log strategy to use, e.g. {:log-strategy string}          |
+| `:log-to`          | Map                         | A map containing the [log strategy](docs/log-strategies.md) to use, e.g. {:log-strategy string}          |
 |                    |                             |                                                                                |
 
 #### Result:

doc/log-strategies.md

@@ -0,0 +1,34 @@
+# Log strategies
+
+This library offers two ways to access the logs of the running container: The :string strategy and the :fn strategy.
+
+## String Strategy
+
+The `:string` strategy sets up a function in the returned map, under the `string-log` key. This function enables the
+dumping of the logs when passed to the `dump-logs` function.
+
+Example:
+
+```clojure
+{:log-strategy :string}
+```
+
+Then, later in your program, you can access the logs thus:
+
+```clojure
+(def container-config (tc/start! container))
+(tc/dump-logs container-config)
+```
+
+## Function Strategy
+
+The `:fn` strategy accepts an additional parameter `:function` in the configuration map, which allows you to pass a
+function to the Testcontainers log mechanism which accepts a single String parameter and gets called for every log line.
+This way you can pass the container logging on to the logging library of your choice.
+
+Example:
+
+```clojure
+{:log-strategy :fn
+ :function     (fn [log-line] (println "From Container: " log-line)}
+```

project.clj

@@ -23,7 +23,8 @@
                                   [orchestra "2021.01.01-1"]
                                   [org.clojure/tools.namespace "1.2.0"]
                                   [org.testcontainers/postgresql "1.16.3"]
-                                  [com.fzakaria/slf4j-timbre "0.3.21"]]
+                                  [com.fzakaria/slf4j-timbre "0.3.21"]
+                                  [nrepl "0.9.0"]]
                    :source-paths ["dev-src"]}}
 
   :target-path "target/%s")

src/clj_test_containers/core.clj

@@ -13,6 +13,8 @@
     GenericContainer
     Network)
    (org.testcontainers.containers.output
+    BaseConsumer
+    OutputFrame
     ToStringConsumer)
    (org.testcontainers.containers.wait.strategy
     Wait)
@@ -278,11 +280,10 @@
      :stderr    (.getStderr result)}))
 
 (defmulti log
-  "Sets a log strategy on the container as a means of accessing the container
+  "Sets a log strategy on the container as a means of accessing the container logs.
-          logs.  It currently only supports a :string as the strategy to use.
 
                   ## String Strategy
-          The :string strategy sets up a function in the returned map, under the
+                  The `:string` strategy sets up a function in the returned map, under the
                   `string-log` key. This function enables the dumping of the logs when passed to
                   the `dump-logs` function.
 
@@ -297,6 +298,18 @@
                   ```clojure
                   (def container-config (tc/start! container))
                   (tc/dump-logs container-config)
+                  ```
+
+                  ## Function Strategy
+                  The `:fn` strategy accepts an additional parameter `:function` in the configuration
+                  map, which allows you to pass a function to the Testcontainers log mechanism
+                  which accepts a single String parameter and gets called for every log line. This
+                  way you can pass the container logging on to the logging library of your choice.
+
+                  Example:
+                  ```clojure
+                  {:log-strategy :fn
+                   :function (fn [log-line] (println \"From Container: \" log-line)}
                   ```
                    "
   :log-strategy)
@@ -309,9 +322,12 @@
             (-> (.toUtf8String to-string-consumer)
                 (clojure.string/replace #"\n+" "\n")))}))
 
-(defmethod log :slf4j [_ _] nil)                            ; Not yet implemented
+(defmethod log :fn [{:keys [function]} ^GenericContainer container]
+  (.followOutput container (proxy [BaseConsumer] []
+                             (^void accept [^OutputFrame frame]
+                               (function (.getUtf8String frame))))))
 
-(defmethod log :default [_ _] nil)                          ; Not yet implemented
+(defmethod log :default [_ _] nil)
 
 (defn dump-logs
   "Dumps the logs found by invoking the function on the :string-log key"

test/clj_test_containers/core_test.clj

@@ -20,13 +20,20 @@
       (is (nil? (:id stopped-container)))
       (is (nil? (:mapped-ports stopped-container)))))
 
-  (testing "Testing log access to the container"
+  (testing "Testing log access to the container with string logs"
     (let [container (sut/init {:container (PostgreSQLContainer. "postgres:12.2")
                                :log-to    {:log-strategy :string}})
           initialized-container (sut/start! container)]
       (Thread/sleep 500)
       (is (includes? (sut/dump-logs initialized-container) "database system is ready to accept connections"))))
 
+  (testing "Testing log access to the container with function logs"
+    (let [logs (atom [])]
+      (sut/start! (sut/init {:container (PostgreSQLContainer. "postgres:12.2")
+                             :log-to    {:log-strategy :fn
+                                         :function     #(swap! logs conj %)}}))
+      (is (filter #(includes? "database system is ready to accept connections" %) @logs))))
+
   (testing "Testing basic testcontainer generic image initialisation with wait for log message"
     (let [container (sut/create {:image-name    "postgres:12.2"
                                  :exposed-ports [5432]