Editing GIST with cURL - bash

Question

#!/bin/bash
COMMIT=$(git log -1 --pretty=format:'{"subject": "%s", "name": "xxx", "date": "%cD"}')
curl -X PATCH -d'{"files": {"latest-commit": {"content": "$COMMIT"}}}' -u user:xxxx https://api.github.com/gists/xxx
This just shows $COMMIT in the Gist. I tried playing with ''' and stuff but cannot make this work.

Answer 1

Your $COMMIT variable is not expanded to its value, because it is enclosed in single-quotes.
About an actual implementation in Bash
The GitHub API require you send the file content as a string: https://developer.github.com/v3/gists/#input-1
When file content contains newlines, double quotes or other characters needing an escaping within a string, the most appropriate shell tool to fill-in and escape the content string is jq.
JavaScript provide a JSON.stringify() method, but here in the shell world, we use jq to process JSON data.
If you don't have jq available you can convert the content of the file, to a properly escaped JSON string with GNU sed this way:
# compose the GitHub API JSON data payload
# to update the latest-commit.json file in the $gist_id
# uses sed to properly fill-in and escape the content string
read -r -d '' json_data_payload <<EOF
{
"description": "Updated from GitHub API call in Bash",
"files": {
"latest-commit.json": {
"filename": "latest-commit.json",
"content": "$(
sed ':a;N;$!ba;s/\n/\\n/g;s/\r/\\r/g;s/\t/\\t/g;s/"/\\"/g;' <<<"$latest_commit_json_content"
)"
}
}
}
EOF
This is how jq is used to fill the content string with proper escaping:
json_data_payload="$(
jq \
--arg content "$latest_commit_json_content" \
--compact-output \
'.files."latest-commit.json".content = $content' \
<<'EOF'
{
"files": {
"latest-commit.json": {
"filename": "latest-commit.json",
"content": ""
}
}
}
EOF
)"
Detailed and tested ok implementation:
#!/usr/bin/env bash
# Set to the gist id to update
gist_id='4b85f310233a6b9d385643fa3a889d92'
# Uncomment and set to your GitHub API OAUTH token
github_oauth_token='###################'
# Or uncomment this and set to your GitHub username:password
#github_user="user:xxxx"
github_api='https://api.github.com'
gist_description='Gist update with API call from a Bash script'
filename='latest-commit.json'
get_file_content() {
# Populate variables from the git log of latest commit
# reading null delimited strings for safety on special characters
{
read -r -d '' subject
read -r -d '' author
read -r -d '' date
} < <(
# null delimited subject, author, date
git log -1 --format=$'%s%x00%aN%x00%cD%x00'
)
# Compose the latest commit JSON, and populate it with the latest commit
# variables, using jq to ensure proper encoding and formatting of the JSON
read -r -d '' jquery <<'EOF'
.subject = $subject |
.author = $author |
.date = $date
EOF
jq \
--null-input \
--arg subject "$subject" \
--arg author "$author" \
--arg date "$date" \
"$jquery"
}
# compose the GitHub API JSON data payload
# to update the latest-commit.json file in the $gist_id
# uses jq to properly fill-in and escape the content string
# and compact the output before transmission
get_gist_update_json() {
read -r -d '' jquery <<'EOF'
.description = $description |
.files[$filename] |= (
.filename = $filename |
.content = $content
)
EOF
jq \
--null-input \
--compact-output \
--arg description "$gist_description" \
--arg filename "$filename" \
--arg content "$(get_file_content)" \
"$jquery"
}
# prepare the curl call with options for the GitHub API request
github_api_request=(
curl # The command to send the request
--fail # Return shell error if request unsuccessful
--request PATCH # The request type
--header "Content-Type: application/json" # The MIME type of the request
--data "$(get_gist_update_json)" # The payload content of the request
)
if [ -n "${github_oauth_token:-}" ]; then
github_api_request+=(
# Authenticate the GitHub API with a OAUTH token
--header "Authorization: token $github_oauth_token"
)
elif [ -n "${github_user:-}" ]; then
github_api_request+=(
# Authenticate the GitHub API with an HTTP auth user:pass
--user "$github_user"
)
else
echo 'GitHub API require either an OAUTH token or a user:pass' >&2
exit 1
fi
github_api_request+=(
-- # End of curl options
"$github_api/gists/$gist_id" # The GitHub API url to address the request
)
# perform the GitHub API request call
if ! "${github_api_request[#]}"; then
echo "Failed execution of:" >&2
env printf '%q ' "${github_api_request[#]}" >&2
echo >&2
fi
Here is the generated curl call with my token redacted out:
curl --fail --request PATCH --header 'Content-Type: application/json' \
--data '{"description":"Hello World Examples","files":{"latest-commit.json":{"filename":"latest-commit.json","content":"{\n \"subject\": \"depricate Phosphor\",\n \"name\": \"Blood Asp\",\n \"date\": \"Wed, 12 Dec 2018 18:55:39 +0100\"\n}"}}}' \
--header 'Authorization: token xxxx-redacted-xxxx' \
-- \
https://api.github.com/gists/4b85f310233a6b9d385643fa3a889d92
And the JSON response it replied with:
"url": "https://api.github.com/gists/4b85f310233a6b9d385643fa3a889d92",
"forks_url": "https://api.github.com/gists/4b85f310233a6b9d385643fa3a889d92/forks",
"commits_url": "https://api.github.com/gists/4b85f310233a6b9d385643fa3a889d92/commits",
"id": "4b85f310233a6b9d385643fa3a889d92",
"node_id": "MDQ6R2lzdDRiODVmMzEwMjMzYTZiOWQzODU2NDNmYTNhODg5ZDky",
"git_pull_url": "https://gist.github.com/4b85f310233a6b9d385643fa3a889d92.git",
"git_push_url": "https://gist.github.com/4b85f310233a6b9d385643fa3a889d92.git",
"html_url": "https://gist.github.com/4b85f310233a6b9d385643fa3a889d92",
"files": {
"latest-commit.json": {
"filename": "latest-commit.json",
"type": "application/json",
"language": "JSON",
"raw_url": "https://gist.githubusercontent.com/leagris/4b85f310233a6b9d385643fa3a889d92/raw/7cb7f9d4a0170daf5083929858fb7eef706f8b59/latest-commit.json",
"size": 105,
"truncated": false,
"content": "{\n \"subject\": \"depricate Phosphor\",\n \"name\": \"Blood Asp\",\n \"date\": \"Wed, 12 Dec 2018 18:55:39 +0100\"\n}"
}
},
...