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ggregory pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/commons-lang.git
The following commit(s) were added to refs/heads/master by this push:
new 3e994821b Javadoc
3e994821b is described below
commit 3e994821b4e3ceed87d32a7b332bf1323802b063
Author: ggregory <[email protected]>
AuthorDate: Tue Aug 19 09:56:51 2025 -0400
Javadoc
---
.../apache/commons/lang3/RuntimeEnvironment.java | 75 +++++++++++++++++-----
1 file changed, 60 insertions(+), 15 deletions(-)
diff --git a/src/main/java/org/apache/commons/lang3/RuntimeEnvironment.java
b/src/main/java/org/apache/commons/lang3/RuntimeEnvironment.java
index f747a41c6..7be1ee9e9 100644
--- a/src/main/java/org/apache/commons/lang3/RuntimeEnvironment.java
+++ b/src/main/java/org/apache/commons/lang3/RuntimeEnvironment.java
@@ -36,28 +36,71 @@ private static boolean fileExists(final String path) {
/**
* Tests whether we are running in a container like Docker or Podman.
+ * <p>
+ * <em>The following may change if we find better detection logic.</em>
+ * </p>
+ * <p>
+ * We roughly follow the logic in SystemD:
+ * </p>
+ * <p>
+ * <a href=
+ *
"https://github.com/systemd/systemd/blob/0747e3b60eb4496ee122066c844210ce818d76d9/src/basic/virt.c#L692";>https://github.com/systemd/systemd/blob/0747e3b60eb4496ee122066c844210ce818d76d9/src/basic/virt.c#L692</a>
+ * </p>
+ * <p>
+ * We check the `container` environment variable of process 1:
+ * </p>
+ * <ol>
+ * <li>If the variable is empty, we return false. This includes the case,
where the container developer wants to hide the fact that the application runs
in
+ * a container.</li>
+ * <li>If the variable is not empty, we return true.</li>
+ * <li>If the variable is absent, we continue.</li>
+ * <li>We check files in the container. According to SystemD:/
+ * <ol>
+ * <li>/.dockerenv is used by Docker.</li>
+ * <li>/run/.containerenv is used by PodMan.</li>
+ * </ol>
+ * </li>
+ * </ol>
*
- * @return whether we are running in a container like Docker or Podman.
Never null
+ * @return whether we are running in a container like Docker or Podman.
Never null.
+ * @see <a
href="https://github.com/systemd/systemd/blob/0747e3b60eb4496ee122066c844210ce818d76d9/src/basic/virt.c#L692";>SystemD
virt.c</a>
*/
public static Boolean inContainer() {
return inContainer(StringUtils.EMPTY);
}
+ /**
+ * Tests whether we are running in a container like Docker or Podman.
+ * <p>
+ * <em>The following may change if we find better detection logic.</em>
+ * </p>
+ * <p>
+ * We roughly follow the logic in SystemD:
+ * </p>
+ * <p>
+ * <a href=
+ *
"https://github.com/systemd/systemd/blob/0747e3b60eb4496ee122066c844210ce818d76d9/src/basic/virt.c#L692";>https://github.com/systemd/systemd/blob/0747e3b60eb4496ee122066c844210ce818d76d9/src/basic/virt.c#L692</a>
+ * </p>
+ * <p>
+ * We check the `container` environment variable of process 1:
+ * </p>
+ * <ol>
+ * <li>If the variable is empty, we return false. This includes the case,
where the container developer wants to hide the fact that the application runs
in
+ * a container.</li>
+ * <li>If the variable is not empty, we return true.</li>
+ * <li>If the variable is absent, we continue.</li>
+ * <li>We check files in the container. According to SystemD:/
+ * <ol>
+ * <li>/.dockerenv is used by Docker.</li>
+ * <li>/run/.containerenv is used by PodMan.</li>
+ * </ol>
+ * </li>
+ * </ol>
+ *
+ * @return Whether we are running in a container like Docker or Podman.
+ * @see <a
href="https://github.com/systemd/systemd/blob/0747e3b60eb4496ee122066c844210ce818d76d9/src/basic/virt.c#L692";>SystemD
virt.c</a>
+ */
static boolean inContainer(final String dirPrefix) {
- /*
- Roughly follow the logic in SystemD:
-
https://github.com/systemd/systemd/blob/0747e3b60eb4496ee122066c844210ce818d76d9/src/basic/virt.c#L692
-
- We check the `container` environment variable of process 1:
- If the variable is empty, we return false. This includes the case,
where the container developer wants to hide the fact that the application runs
in a container.
- If the variable is not empty, we return true.
- If the variable is absent, we continue.
-
- We check files in the container. According to SystemD:
- /.dockerenv is used by Docker.
- /run/.containerenv is used by PodMan.
-
- */
final String value = readFile(dirPrefix + "/proc/1/environ",
"container");
if (value != null) {
return !value.isEmpty();
@@ -79,12 +122,14 @@ private static String readFile(final String envVarFile,
final String key) {
// Split by null byte character
final String[] lines =
content.split(String.valueOf(CharUtils.NUL));
final String prefix = key + "=";
+ // @formatter:off
return Arrays.stream(lines)
.filter(line -> line.startsWith(prefix))
.map(line -> line.split("=", 2))
.map(keyValue -> keyValue[1])
.findFirst()
.orElse(null);
+ // @formatter:on
} catch (final IOException e) {
return null;
}
