Maven

<profile>
    <id>ext</id>
    <activation>
        <file>
            <missing>${basedir}/ext</missing>
        </file>
    </activation>
</profile>

Distribution

<settings>
    [...]
    <profiles>
        <profile>
        <id>nex</id>
        <properties>
            <altSnapshotDeploymentRepository>academia.snapshots::default::https://nex.chorke.org/repository/maven/snapshots</altSnapshotDeploymentRepository>
            <altReleaseDeploymentRepository>academia.releases::default::https://nex.chorke.org/repository/maven/releases</altReleaseDeploymentRepository>
        </properties>
        </profile>
    </profiles>
</settings>

Security

M2_MASTER_PASS='<master.password>';\
M2_SECURITY_XML="${HOME}/.m2/settings-security.xml";\
printf -v M2_MASTER_HASH '%s' $(mvn --encrypt-master-password ${M2_MASTER_PASS});\
if  [ ! -f ${M2_SECURITY_XML} ]||[ ! -s ${M2_SECURITY_XML} ];then\
  cat << EOF | tee ${M2_SECURITY_XML} >/dev/null
<?xml version="1.0" encoding="UTF-8"?>
<settingsSecurity>
  <master>${M2_MASTER_HASH}</master>
</settingsSecurity>
EOF
fi

---

M2_NEXUS_USER='<nexus.username>';\
M2_NEXUS_PASS='<nexus.password>';\
M2_SETTINGS_XML="${HOME}/.m2/settings.xml";\
printf -v M2_NEXUS_HASH '%s' $(mvn --encrypt-password ${M2_NEXUS_PASS});\
if  [ ! -f ${M2_SETTINGS_XML} ]||[ ! -s ${M2_SETTINGS_XML} ];then\
  cat << EOF | tee ${M2_SETTINGS_XML} >/dev/null
<?xml version="1.0" encoding="UTF-8"?>
<settings xmlns="http://maven.apache.org/SETTINGS/1.2.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.2.0 https://maven.apache.org/xsd/settings-1.2.0.xsd">
 <servers>
    <server>
      <id>academia.releases</id>
        <username>${M2_NEXUS_USER}</username>
        <password>${M2_NEXUS_HASH}</password>
    </server>
    <server>
      <id>academia.snapshots</id>
        <username>${M2_NEXUS_USER}</username>
        <password>${M2_NEXUS_HASH}</password>
     </server>
  </servers>

  <mirrors>
    <mirror>
      <id>academia</id>
      <mirrorOf>*</mirrorOf>
      <url>https://cdn.chorke.org/nexus/repository/m2/</url>
    </mirror>
  </mirrors>

  <profiles>
    <profile>
      <id>academia</id>
      <properties>
        <altSnapshotDeploymentRepository>academia.snapshots::default::https://cdn.chorke.org/nexus/repository/m2-snapshots</altSnapshotDeploymentRepository>
        <altReleaseDeploymentRepository>academia.releases::default::https://cdn.chorke.org/nexus/repository/m2-releases</altReleaseDeploymentRepository>
      </properties>
      <repositories>
        <repository>
          <id>central</id>
          <url>http://central</url>
          <releases><enabled>true</enabled></releases>
          <snapshots><enabled>true</enabled></snapshots>
        </repository>
      </repositories>
     <pluginRepositories>
        <pluginRepository>
          <id>central</id>
          <url>http://central</url>
          <releases><enabled>true</enabled></releases>
          <snapshots><enabled>true</enabled></snapshots>
        </pluginRepository>
      </pluginRepositories>
    </profile>
  </profiles>
  
  <activeProfiles>
    <activeProfile>academia</activeProfile>
  </activeProfiles>
</settings>
EOF
fi

References

altDeploymentRepository vs. altReleaseDeploymentRepository Externalized Maven Distribution Management File specification used to activate the profile Activate a Maven Profile if missing a file Maven Deploy Optional Parameters Maven Encrypt Master Password Maven Deploy External JAR Bash Multi-line string Nexus:Maven Nexus	Maven Checkstyle Plugin
CocoaPods Conan Bazel NPM Ant Ivy