Add update-version task (#172)

This commit adds an update version task to cargo make.

The task is implemented as a rust script to work cross-platform
and to allow retrieving the current version from Cargo.toml
package version, for replacement in docs. It assumes that
the version to be updated across all docs is the same.

(cherry picked from commit 1c6b509)

Makefile.toml

@@ -211,6 +211,100 @@ end
 """
 ]
 
+[tasks.update-version]
+description = "Updates the package versions and version in docs"
+condition = { env_set = ["NEW_VERSION"] }
+script_runner = "@rust"
+script = '''
+//! ```cargo
+//! [dependencies]
+//! envmnt = "*"
+//! glob = "0.3.0"
+//! semver = "0.11.0"
+//! toml_edit = "0.2.0"
+//! ```
+extern crate glob;
+extern crate semver;
+
+use std::fs::{File, OpenOptions};
+use std::io::{Read, Write};
+use std::path::Path;
+use glob::glob;
+use semver::Version;
+fn main() {
+    let new_version = {
+        let v = envmnt::get_or_panic("NEW_VERSION");
+        v.parse::<Version>().expect("NEW_VERSION must be a valid semantic version")
+    };
+    let old_version = update_cargo_toml(&new_version);
+    update_docs(&old_version, &new_version);
+}
+
+fn update_docs(old_version: &str, new_version: &Version) {
+    for entry in glob("docs/*.asciidoc").unwrap()
+        .chain(glob("README.md").unwrap())
+        .chain(glob("elasticsearch/src/lib.rs").unwrap()) {
+        match entry {
+            Ok(path) => {
+                let mut content = read_file(&path);
+                content = content.replace(
+                    &format!("elasticsearch = \"{}\"", old_version),
+                    &format!("elasticsearch = \"{}\"", new_version.to_string()));
+                write_file(&path, content);
+            }
+            Err(e) => panic!("{:?}", e),
+        }
+    }
+}
+
+fn update_cargo_toml(new_version: &Version) -> String {
+    let mut old_version = String::new();
+    for entry in glob("**/Cargo.toml").unwrap() {
+        match entry {
+            Ok(path) => {
+                // skip workspace and target tomls
+                if path.starts_with("target") || path.to_string_lossy() == "Cargo.toml" {
+                    continue;
+                }
+
+                let content = read_file(&path);
+                let mut toml = content.parse::<toml_edit::Document>().expect("Could not parse Cargo.toml");
+                let name = toml["package"]["name"].as_str().expect("toml has name");
+
+                // store the version from the elasticsearch package to target replacement in docs
+                if name == "elasticsearch" {
+                    old_version = toml["package"]["version"]
+                        .as_str()
+                        .expect("toml has version")
+                        .to_string();
+                }
+
+                toml["package"]["version"] = toml_edit::value(new_version.to_string());
+                write_file(&path, toml.to_string());
+            },
+            Err(e) => panic!("{:?}", e),
+        }
+    }
+    old_version
+}
+
+fn read_file<P: AsRef<Path>>(path: P) -> String {
+    let mut file = File::open(path).unwrap();
+    let mut raw_data = String::new();
+    file.read_to_string(&mut raw_data).unwrap();
+    raw_data
+}
+
+fn write_file<P: AsRef<Path>>(path: P, content: String) {
+    let mut file = OpenOptions::new()
+        .write(true)
+        .truncate(true)
+        .open(path)
+        .unwrap();
+    file.write_all(content.as_bytes()).unwrap();
+}
+'''
+
 [tasks.default]
 clear = true
 script_runner = "@duckscript"
@@ -225,6 +319,8 @@ script = ['''
     echo - test-generator: Generates and runs api_generator package tests
     echo - test: Runs elasticsearch package tests against a given Elasticsearch version
     echo
+    echo - update-version: Updates the version
+    echo       pass NEW_VERSION environment variable for version
     echo - generate-release-notes: Generates release notes for elasticsearch crate.
     echo       pass OLD_VERSION and NEW_VERSION environment variables to match release version GitHub labels e.g. v7.9.0-alpha.1
     echo - package: Packages the elasticsearch crate.